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AFUE, HSPF and COP, how do they relate?
http://www.energyexperts.org/fuelcalc/default.asp
wants me to calculate heat pump heating efficiencies based on the AFUE of the heat pump, but I see them measured in HSPF (Heating System Performance Factor) at the state website which discusses rebates http://egov.oregon.gov/ENERGY/CONS/RES/tax/HVAC.shtml Other USENET discussions (here and elsewhere) discuss a third measure, the COP (Coefficiency of Perfomance). Are there conversion factors from one to the other? Given one, how can I calculate the others? If there is none, is there an alternate web site I can use to estimate the result if I replace a gas furnace with a heat pump? Thank you kindly. -- K7AAY John Bartley Portland OR USA views are mine, all mine. http://kiloseven.blogspot.com "The Temporal Office says you have to do this. No, no explanation. Here's your stuffed tuna and an airhorn." - James Nicoll |
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John;
This may be a bit lengthy but I'll try to explain as breifly as possible. The only way you can compare one unit to another [efficiency] is work in the same language. In other words, heat [btu/h]. Capacity vs. energy consumed. To relate, a heat pump is measured in HSPF [Heating Seasonal Performance Factor] and COP [Coefficient of Performance.] Both have relationship [ratio] between the energy consumed vs. heat energy delivered. A furnace on the other hand consumes natural gas or propane gas and delivers heat energy vs. energy consumed and has a specifiec amount of waster AFUE [American Fuel Utilization Efficienty] The easiest way to make a comparison is to convert the energy the 'heat pump' uses [kWh] to btu/h. (3413 btu/h per kWh). Then compare the amount of btu/h energy delivered to the occupied space. This is representative of the COP. [A heat pump with a COP of say 2.0 has a 'coefficent' of 200% as compared to a electric strip heater of the same capacity.] Keep in mind though, that when the conditions change [outdoor temp's] the COP decreases as well as the capacity delivered. On the other hand, a natural gas furnace delivers the same btu/h no matter what the outdoor temperature is. But, is either 80% efficient or 90% - 93% depending on the model. The remainder of the which goes up the flu stack. When you compare $ for $ [which if you ask, I will be happy to send you a power point presentation based on the costs associated with different energy sources and different uses] you would find a heat pump actually is just as effient as a gas fired heater, provided it doesn't reach a low COP [low outdoor temp's]. This 'higher efficency' state only occurrs around 70º F ambient. When the temp. outside drops to 50º F the COP really starts to take a dive and the gas fired furnace becomes the winner. [More efficent.] The time to consider a heat pump is when other fuels are either expensive, or unavailable. I hope this is helpful. Zyp wrote in message ... http://www.energyexperts.org/fuelcalc/default.asp wants me to calculate heat pump heating efficiencies based on the AFUE of the heat pump, but I see them measured in HSPF (Heating System Performance Factor) at the state website which discusses rebates http://egov.oregon.gov/ENERGY/CONS/RES/tax/HVAC.shtml Other USENET discussions (here and elsewhere) discuss a third measure, the COP (Coefficiency of Perfomance). Are there conversion factors from one to the other? Given one, how can I calculate the others? If there is none, is there an alternate web site I can use to estimate the result if I replace a gas furnace with a heat pump? Thank you kindly. -- K7AAY John Bartley Portland OR USA views are mine, all mine. http://kiloseven.blogspot.com "The Temporal Office says you have to do this. No, no explanation. Here's your stuffed tuna and an airhorn." - James Nicoll |
On Sun, 20 Feb 2005 13:34:25 -0800, "Zyp" wrote:
John; This may be a bit lengthy but I'll try to explain as breifly as possible. The only way you can compare one unit to another [efficiency] is work in the same language. In other words, heat [btu/h]. Capacity vs. energy consumed. To relate, a heat pump is measured in HSPF [Heating Seasonal Performance Factor] and COP [Coefficient of Performance.] Both have relationship [ratio] between the energy consumed vs. heat energy delivered. A furnace on the other hand consumes natural gas or propane gas and delivers heat energy vs. energy consumed and has a specifiec amount of waster AFUE [American Fuel Utilization Efficienty] The easiest way to make a comparison is to convert the energy the 'heat pump' uses [kWh] to btu/h. (3413 btu/h per kWh). Then compare the amount of btu/h energy delivered to the occupied space. This is representative of the COP. [A heat pump with a COP of say 2.0 has a 'coefficent' of 200% as compared to a electric strip heater of the same capacity.] Keep in mind though, that when the conditions change [outdoor temp's] the COP decreases as well as the capacity delivered. On the other hand, a natural gas furnace delivers the same btu/h no matter what the outdoor temperature is. But, is either 80% efficient or 90% - 93% depending on the model. The remainder of the which goes up the flu stack. When you compare $ for $ [which if you ask, I will be happy to send you a power point presentation based on the costs associated with different energy sources and different uses] you would find a heat pump actually is just as effient as a gas fired heater, Nonsequitor. That's like saying the moon is as low as water - it simply doesn't make any sense at all, it's gibberish. What you meant to say was 'cost effective'. This can only be computed when fuel costs are known and stated ( gas v oil v electricity ). provided it doesn't reach a low COP [low outdoor temp's]. This 'higher efficency' state only occurrs around 70º F ambient. Oh, ****ing bull****. WTF are you talking about ? You're supposing someone runs their heat pump in heat mode when it's 70 outside ??? And that's the 'only' time heat pumps make economic sense ??? Bull****. Nonsense. When the temp. outside drops to 50º F the COP really starts to take a dive and the gas fired furnace becomes the winner. [More efficent.] Bzzt. Wrong. At ANY temp above the economic balance point, a heat pump will continue to provide cheaper heat, IE, 'more heat energy out of it than you put electrical ( source ) energy into it '. IOW - even at 30 F or less, a heat pump continues to provide economical heat. Now, it may very well not provide *ALL* the heat you need at that point, but what heat it DOES provide is less expensive than anything else, such as fuel-fired, etc, *IF* the fuel costs made sense to begin with. The economic balance point is derived from the cost of fuels and electricity at the time. In areas with high gas/oil costs and low KW costs, it makes sense. In areas with high KW costs and low oil/gas costs, it does not. The time to consider a heat pump is when other fuels are either expensive, or unavailable. I hope this is helpful. Misleading in it's bulk. You started of with a few simple facts that you got right, but then you ****ed up completely. If you're going to give advice on a subject, you should study it and understand it first. Paul ( pjm @ pobox . com ) - remove spaces to email me 'Some days, it's just not worth chewing through the restraints.' HVAC/R program for Palm PDA's Free demo now available online http://pmilligan.net/palm/ Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/ |
Paul;
Then give the advice. If you are so bent on being the perfectionist.... I tried to answer it as simply as possible. And your correct [symantics.] But that's fine. Like I said you are obviously bent on putting other's down. All of your posts are either telling someone to get the **** out or someone's wrong in their posting. I haven't truly seen anything positive from your end. I don't have to put up with your bull either. I can just troll .... Zyp p j m@see _my _sig _for_address.com wrote in message ... On Sun, 20 Feb 2005 13:34:25 -0800, "Zyp" wrote: John; This may be a bit lengthy but I'll try to explain as breifly as possible. The only way you can compare one unit to another [efficiency] is work in the same language. In other words, heat [btu/h]. Capacity vs. energy consumed. To relate, a heat pump is measured in HSPF [Heating Seasonal Performance Factor] and COP [Coefficient of Performance.] Both have relationship [ratio] between the energy consumed vs. heat energy delivered. A furnace on the other hand consumes natural gas or propane gas and delivers heat energy vs. energy consumed and has a specifiec amount of waster AFUE [American Fuel Utilization Efficienty] The easiest way to make a comparison is to convert the energy the 'heat pump' uses [kWh] to btu/h. (3413 btu/h per kWh). Then compare the amount of btu/h energy delivered to the occupied space. This is representative of the COP. [A heat pump with a COP of say 2.0 has a 'coefficent' of 200% as compared to a electric strip heater of the same capacity.] Keep in mind though, that when the conditions change [outdoor temp's] the COP decreases as well as the capacity delivered. On the other hand, a natural gas furnace delivers the same btu/h no matter what the outdoor temperature is. But, is either 80% efficient or 90% - 93% depending on the model. The remainder of the which goes up the flu stack. When you compare $ for $ [which if you ask, I will be happy to send you a power point presentation based on the costs associated with different energy sources and different uses] you would find a heat pump actually is just as effient as a gas fired heater, Nonsequitor. That's like saying the moon is as low as water - it simply doesn't make any sense at all, it's gibberish. What you meant to say was 'cost effective'. This can only be computed when fuel costs are known and stated ( gas v oil v electricity ). provided it doesn't reach a low COP [low outdoor temp's]. This 'higher efficency' state only occurrs around 70º F ambient. Oh, ****ing bull****. WTF are you talking about ? You're supposing someone runs their heat pump in heat mode when it's 70 outside ??? And that's the 'only' time heat pumps make economic sense ??? Bull****. Nonsense. When the temp. outside drops to 50º F the COP really starts to take a dive and the gas fired furnace becomes the winner. [More efficent.] Bzzt. Wrong. At ANY temp above the economic balance point, a heat pump will continue to provide cheaper heat, IE, 'more heat energy out of it than you put electrical ( source ) energy into it '. IOW - even at 30 F or less, a heat pump continues to provide economical heat. Now, it may very well not provide *ALL* the heat you need at that point, but what heat it DOES provide is less expensive than anything else, such as fuel-fired, etc, *IF* the fuel costs made sense to begin with. The economic balance point is derived from the cost of fuels and electricity at the time. In areas with high gas/oil costs and low KW costs, it makes sense. In areas with high KW costs and low oil/gas costs, it does not. The time to consider a heat pump is when other fuels are either expensive, or unavailable. I hope this is helpful. Misleading in it's bulk. You started of with a few simple facts that you got right, but then you ****ed up completely. If you're going to give advice on a subject, you should study it and understand it first. Paul ( pjm @ pobox . com ) - remove spaces to email me 'Some days, it's just not worth chewing through the restraints.' HVAC/R program for Palm PDA's Free demo now available online http://pmilligan.net/palm/ Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/ |
Found the aforementionsed site, plus others, but they are either opaque
(don't reveal how they calculate... which, after the flap over the bad 'hockey stick' model that was used to justify Kyoto http://www.jerrypournelle.com/view/view349.html#hockeystick makes me mistrust them, as they are probably assuming we run our house hotter than we do, our house is less well sealed than it is, or it's larger than it is) or ask for data in arcane formats (i.e., AFUE for heat pumps). Also, a search for the conversion factors themselves was not productive. I did my homework first. |
On Sun, 20 Feb 2005 14:29:58 -0800, "Zyp" wrote:
Paul; Then give the advice. If you are so bent on being the perfectionist.... I tried to answer it as simply as possible. And your correct [symantics.] But that's fine. **** semantics, I was correct on FACTS and INFORMATION. You were WRONG. You post was FACTUALLY INCORRECT and misleading in the extreme. You suggested that heat pumps are only effective and efficient at 70 + ambient, and that is purest bull****. You suggested that they are practically worthless under 50 F, and that also is purrest bull****. I'm not playing word games here, I'm telling anyone reading this thread that you stated the facts incorrectly, and that they were mislead by your post, if they believed it. Like I said you are obviously bent on putting other's down. I'm 'bent' on assholes not giving bad advice and incorrect information. If you fit in that category, that's your problem, not mine. If you can't stand being corrected, then you have 'issues'. All of your posts are either telling someone to get the **** out or someone's wrong in their posting. I haven't truly seen anything positive from your end. You clueless ****wit. If I don't tell you you're wrong, then how do you learn ? What is your suggestion, that when you post wrong ****, everyone else should just go along with it ? Well, I would suggest that Britney Spears show up at my door tonight drunk and horny, but I don't think either event is likely. Here I try to teach you something about heatpumps, I try to correct your WRONG statements so you can LEARN something, and all you can do is take it as a personal attack. You display not only your ignorance, but also how you acheived it. I don't have to put up with your bull either. I can just troll .... And blow me. Paul ( pjm @ pobox . com ) - remove spaces to email me 'Some days, it's just not worth chewing through the restraints.' HVAC/R program for Palm PDA's Free demo now available online http://pmilligan.net/palm/ Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/ |
Thank you for the useful basic information... much better than raving
'experts' who take the time for flame, but don't themselves provide useful information. A continues search found: http://www.energyoutlet.com/res/heat...fficiency.html which states: snip "A heat pump with an HSPF of 6.8 has an "average COP" of 2 for the heating season. To estimate the average COP, divide the HSPF by 3.4. "Don't assume the HSPF will be an accurate predictor of your actual installed performance. HSPF assumes specific conditions that, are unlikely to coincide with your climate. " snip I assume the COP is equal to the AFUE (except the AFUE is normally expressed in terms of %). Is that fairly accurate? |
On Sun, 20 Feb 2005 13:34:25 -0800, "Zyp" wrote:
John; This may be a bit lengthy but I'll try to explain as breifly as possible. The only way you can compare one unit to another [efficiency] is work in the same language. In other words, heat [btu/h]. Capacity vs. energy consumed. To relate, a heat pump is measured in HSPF [Heating Seasonal Performance Factor] and COP [Coefficient of Performance.] Both have relationship [ratio] between the energy consumed vs. heat energy delivered. A furnace on the other hand consumes natural gas or propane gas and delivers heat energy vs. energy consumed and has a specifiec amount of waster AFUE [American Fuel Utilization Efficienty] The easiest way to make a comparison is to convert the energy the 'heat pump' uses [kWh] to btu/h. (3413 btu/h per kWh). Then compare the amount of btu/h energy delivered to the occupied space. This is representative of the COP. [A heat pump with a COP of say 2.0 has a 'coefficent' of 200% as compared to a electric strip heater of the same capacity.] Keep in mind though, that when the conditions change [outdoor temp's] the COP decreases as well as the capacity delivered. On the other hand, a natural gas furnace delivers the same btu/h no matter what the outdoor temperature is. But, is either 80% efficient or 90% - 93% depending on the model. The remainder of the which goes up the flu stack. When you compare $ for $ [which if you ask, I will be happy to send you a power point presentation based on the costs associated with different energy sources and different uses] you would find a heat pump actually is just as effient as a gas fired heater, On Sun, 20 Feb 2005 , p j m@see _my _sig _for_address.com replied: Nonsequitor. That's like saying the moon is as low as water - it simply doesn't make any sense at all, it's gibberish. What you meant to say was 'cost effective'. This can only be computed when fuel costs are known and stated ( gas v oil v electricity ). OK: Here they a Assume 8.27 cents per KwH (current cost is 6.89 cents for a marginal KwH, but the Administration's FY2006 budget proposal assumes BPA will raise their rates 20% to 'market', therefore I will assume that will occur) Assume 1.18 cents per marginal Therm. The existing energy use is 671 Therms/year for heating with the old and failing furnace, and 1,059 KwH for cooling (A/C only heat pump). snip IOW - even at 30 F or less, a heat pump continues to provide economical heat. Now, it may very well not provide *ALL* the heat you need at that point, but what heat it DOES provide is less expensive than anything else, such as fuel-fired, etc, *IF* the fuel costs made sense to begin with. Please don't assume there's any logic to fuel pricing. It's market driven, and the marketeers in this case include Enron's Portland General Electric. The economic balance point is derived from the cost of fuels and electricity at the time. In areas with high gas/oil costs and low KW costs, it makes sense. In areas with high KW costs and low oil/gas costs, it does not. Given the data above, what's your take on the matter at hand? It may be helpful to visit tinyurl.com/64pq6 which is an EPA site with an estimator program, with my data already entered. However, I am uncertain of several of their assumptions. The optimum solution, so far, seems to be a 90% furmace, as over ten years it looks less expensive than the 80% also proposed. Here is the data, transposed from an Excel spreadsheet: Dealer estimate Gross price state rebate net up front cost finance cost total furnace cost est yearly fuel cost (based on projected fuel cost * old furnace efficiency / new furnace efficiency) 5 year cost 10 year cost 15 year cost (All figures in current dollars) I'd be happy to send the spreadsheet by e-mail if desired. Projected gas cost is 1.03 * current fuel cost, based on EPA demand projections of a 3% increase. Very rough, not at all accurate, but best available in a short period of time. Dealer estimate for REPAIR Gross price = $1,560 state rebate = $0 net up front cost = $1,560 finance cost = $0 total furnace cost = $1,560 est yearly fuel cost = $812 5 year cost = $7,181 (assumes re-repair every 5 yr., same cost) 10 year cost = $14,363 15 year cost = $21,544 Dealer estimate for REPLACE W/ 80% EFFICIENT FURNACE Gross price = $ 2,600 state rebate = $0 net up front cost = $2,600 finance cost = $7 on balance we can't pay for immediately total furnace cost = $2,607 est yearly fuel cost = $711 5 year cost = $6,161 10 year cost = $9,714 15 year cost = $13,268 Dealer estimate for REPLACE W/ 90% EFFICIENT FURNACE Gross price = $3,400 state rebate = $200 net up front cost = $3,200 finance cost = $49 total furnace cost = $3,249 est yearly fuel cost = $632 5 year cost = $6,408 10 year cost = $9,567 15 year cost = $12,725 Dealer estimate for REPLACE W/ 94% EFFICIENT FURNACE Gross price = $4,700 state rebate = $550 net up front cost = $4,150 finance cost = $116 total furnace cost = $4,266 est yearly fuel cost = $605 5 year cost = $7,290 10 year cost = $10,314 15 year cost = $13,339 A very rough estimate of an air-air heat pump to replace both the exisiting A/C only heat pump and the gas furnace follows. It deducts our current estimated A/C energy cost from the total energy cost for the 5, 10 and 15 year projections, and uses that 20% hike in electrical cost I mentioned above. It uses the EPA's website (op cit.) ballpark price for an air-air heat pump with HSFP 8.5 & SEER 13 of $4,800, and adds $500 for each step up in effiiciency. It also assumes the existing duct work, which serves us well for summer A/C needs, would be servicable for winter heating. None of these assumptions are sacred, and any improvements in accuracy you suggest would be eagerly listened to, as we have two more estimators from diferent HVAC companies coming tomorrow, and we'd like to make a decision soon after the last departs. Ballpark estimate for REPLACE W/ HEAT PUMP, HSFP 8.5 SEER 13 Gross price = $ 4,800 state rebate = $500 net up front cost = $4,300 finance cost = $126 on balance we can't pay for immediately total replacement cost = $4,426 est yearly energy cost = $811 5 year cost = $8,043 (adjusting for greater cooling efficiency) 10 year cost = $11,660 15 year cost = $15,227 Ballpark estimate for REPLACE W/ HEAT PUMP, HSFP 9 SEER 13.5 Gross price = $ 5,300 state rebate = $600 net up front cost = $4,700 finance cost = $154 on balance we can't pay for immediately total replacement cost = $4,854 est yearly energy cost = $768 5 year cost = $8,256 (adjusting for greater cooling efficiency) 10 year cost = $11,658 15 year cost = $15,060 Ballpark estimate for REPLACE W/ HEAT PUMP, HSFP 9.5 SEER 14 Gross price = $ 5,800 state rebate = $700 net up front cost = $5,100 finance cost = $182 on balance we can't pay for immediately total replacement cost = $5,282 est yearly energy cost = $730 5 year cost = $8,494 (adjusting for greater cooling efficiency) 10 year cost = $11,706 15 year cost = $14,918 BTW, I made several hours of attempts to find anyone in the Portland (OR) metro area who was competent to discuss ground source heat pumps. The one designer I found, who did the People's Food Co-Op system, said the underlying basalt where our home is (said homesite having been selected to avoid soil liquification when the Big One hits) makes vertical well drilling very chancy. That was confirmed by a local well driller, who did some well work about a quarter mile from here. The largest open space we have for a slinky layout is 30' x 60', which makes me think I don't have the room for a ground source heat sink. And, BTW, Paul, have you considered offering your expertise to other Palm Users? PalmSource offers their Expert Guides, and I see there is no HVAC guide. The compensation is modest, but you may find it worthwhile. http://www.palmsource.com/expertguides/ Thank you kindly. -- K7AAY John Bartley Portland OR USA views are mine, all mine. http://kiloseven.blogspot.com "The Temporal Office says you have to do this. No, no explanation. Here's your stuffed tuna and an airhorn." - James Nicoll |
"Zyp" wrote in message ... ambient. When the temp. outside drops to 50º F the COP really starts to take a dive and the gas fired furnace becomes the winner. [More efficent.] Suggest take a *good* look at some typical heat pump performance charts that show outdoor temperatures v/s btu output, and charted along with compressor draw before attempting to give advice. -- SVL |
wrote in message ... BTW, I made several hours of attempts to find anyone in the Portland (OR) metro area who was competent to discuss ground source heat pumps. The one designer I found, who did the People's Food Co-Op system, said the underlying basalt where our home is (said homesite having been selected to avoid soil liquification when the Big One hits) makes vertical well drilling very chancy. That was confirmed by a local well driller, who did some well work about a quarter mile from here. You do realize that you don't have drill until you "hit water" in order to use geothermal...... -- SVL |
Here's another rule of thumb:
"Around 37 F many heat pumps reach what is called the balance point. At or near this temperature the heat pump needs to run constantly to produce enough heat to maintain a comfortable indoor temperature." http://www.askthebuilder.com/294_Hea...ey_Work_.shtml |
wrote in message ... BTW, I made several hours of attempts to find anyone in the Portland (OR) metro area who was competent to discuss ground source heat pumps. The one designer I found, who did the People's Food Co-Op system, said the underlying basalt where our home is (said homesite having been selected to avoid soil liquification when the Big One hits) makes vertical well drilling very chancy. Which kinda begs the question.... Didja happen to ask him about horizontal well drilling ??? G -- SVL |
Yes. However, he said he was likely to hit basalt within 50', which
makes even the design here impractical: http://www.copper.org/applications/p...s_stdy_pa1.htm http://www.copper.org/applications/p...s_stdy_pa2.htm |
wrote in message oups.com... Yes. However, he said he was likely to hit basalt within 50', which makes even the design here impractical: http://www.copper.org/applications/p...al/cs_stdy_pa1. htm http://www.copper.org/applications/p...al/cs_stdy_pa2. htm Direct exchange system.... Im guessing you near the west hills else maybe down towards Oregon City........... some hard rock in both those areas for sure.... The Troutdale aquifer is all sand, and is a perfect area for geo....oh well.......( pun not intended ) I use all heat pumps, an easy choice since nat gas isnt readily for me and i dont feel like bothering with propane........ My brother is up north of here, nearer to Seattle, and he uses a heat pump with gas backup...his having gone through this process just a few years ago...and so so if I was to advise, I would suggest you should consider doing the same--that way you can always change over your primary heat source depending upon what the fossil fuel v/s electricity prices do in the future......and since you are looking 15 years out and all.....that's just too long a time span, IMO--and so it becomes more like gazing at a chrystal ball than it is making accurate economical decisions...anybody's guess..... -- SVL |
On Sun, 20 Feb 2005 19:32:31 -0800, "PrecisionMachinisT"
wrote: Direct exchange system.... Im guessing you near the west hills else maybe down towards Oregon City........... some hard rock in both those areas for sure.... Got it in 2... S. side of Oatfield Hill, between Milwaukie & Gladstone. snip I use all heat pumps, an easy choice since nat gas isnt readily for me and i dont feel like bothering with propane........ snip So, how do things work when KGW is predicting the end of the world in the next ice storm, and it gets below 30F? -- K7AAY John Bartley Portland OR USA views are mine, all mine. http://kiloseven.blogspot.com "The Temporal Office says you have to do this. No, no explanation. Here's your stuffed tuna and an airhorn." - James Nicoll |
What is symantics?
Zyp wrote: Paul; Then give the advice. If you are so bent on being the perfectionist.... I tried to answer it as simply as possible. And your correct [symantics.] But that's fine. Like I said you are obviously bent on putting other's down. All of your posts are either telling someone to get the **** out or someone's wrong in their posting. I haven't truly seen anything positive from your end. I don't have to put up with your bull either. I can just troll .... Zyp p j m@see _my _sig _for_address.com wrote in message ... On Sun, 20 Feb 2005 13:34:25 -0800, "Zyp" wrote: John; This may be a bit lengthy but I'll try to explain as breifly as possible. The only way you can compare one unit to another [efficiency] is work in the same language. In other words, heat [btu/h]. Capacity vs. energy consumed. To relate, a heat pump is measured in HSPF [Heating Seasonal Performance Factor] and COP [Coefficient of Performance.] Both have relationship [ratio] between the energy consumed vs. heat energy delivered. A furnace on the other hand consumes natural gas or propane gas and delivers heat energy vs. energy consumed and has a specifiec amount of waster AFUE [American Fuel Utilization Efficienty] The easiest way to make a comparison is to convert the energy the 'heat pump' uses [kWh] to btu/h. (3413 btu/h per kWh). Then compare the amount of btu/h energy delivered to the occupied space. This is representative of the COP. [A heat pump with a COP of say 2.0 has a 'coefficent' of 200% as compared to a electric strip heater of the same capacity.] Keep in mind though, that when the conditions change [outdoor temp's] the COP decreases as well as the capacity delivered. On the other hand, a natural gas furnace delivers the same btu/h no matter what the outdoor temperature is. But, is either 80% efficient or 90% - 93% depending on the model. The remainder of the which goes up the flu stack. When you compare $ for $ [which if you ask, I will be happy to send you a power point presentation based on the costs associated with different energy sources and different uses] you would find a heat pump actually is just as effient as a gas fired heater, Nonsequitor. That's like saying the moon is as low as water - it simply doesn't make any sense at all, it's gibberish. What you meant to say was 'cost effective'. This can only be computed when fuel costs are known and stated ( gas v oil v electricity ). provided it doesn't reach a low COP [low outdoor temp's]. This 'higher efficency' state only occurrs around 70º F ambient. Oh, ****ing bull****. WTF are you talking about ? You're supposing someone runs their heat pump in heat mode when it's 70 outside ??? And that's the 'only' time heat pumps make economic sense ??? Bull****. Nonsense. When the temp. outside drops to 50º F the COP really starts to take a dive and the gas fired furnace becomes the winner. [More efficent.] Bzzt. Wrong. At ANY temp above the economic balance point, a heat pump will continue to provide cheaper heat, IE, 'more heat energy out of it than you put electrical ( source ) energy into it '. IOW - even at 30 F or less, a heat pump continues to provide economical heat. Now, it may very well not provide *ALL* the heat you need at that point, but what heat it DOES provide is less expensive than anything else, such as fuel-fired, etc, *IF* the fuel costs made sense to begin with. The economic balance point is derived from the cost of fuels and electricity at the time. In areas with high gas/oil costs and low KW costs, it makes sense. In areas with high KW costs and low oil/gas costs, it does not. The time to consider a heat pump is when other fuels are either expensive, or unavailable. I hope this is helpful. Misleading in it's bulk. You started of with a few simple facts that you got right, but then you ****ed up completely. If you're going to give advice on a subject, you should study it and understand it first. Paul ( pjm @ pobox . com ) - remove spaces to email me 'Some days, it's just not worth chewing through the restraints.' HVAC/R program for Palm PDA's Free demo now available online http://pmilligan.net/palm/ Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/ |
Thats the folks what do my anti-virus software ;-)
"Vicki Szaszvari" wrote in message ... What is symantics? Zyp wrote: Paul; Then give the advice. If you are so bent on being the perfectionist.... I tried to answer it as simply as possible. And your correct [symantics.] But that's fine. Like I said you are obviously bent on putting other's down. All of your posts are either telling someone to get the **** out or someone's wrong in their posting. I haven't truly seen anything positive from your end. I don't have to put up with your bull either. I can just troll .... Zyp p j m@see _my _sig _for_address.com wrote in message ... On Sun, 20 Feb 2005 13:34:25 -0800, "Zyp" wrote: John; This may be a bit lengthy but I'll try to explain as breifly as possible. The only way you can compare one unit to another [efficiency] is work in the same language. In other words, heat [btu/h]. Capacity vs. energy consumed. To relate, a heat pump is measured in HSPF [Heating Seasonal Performance Factor] and COP [Coefficient of Performance.] Both have relationship [ratio] between the energy consumed vs. heat energy delivered. A furnace on the other hand consumes natural gas or propane gas and delivers heat energy vs. energy consumed and has a specifiec amount of waster AFUE [American Fuel Utilization Efficienty] The easiest way to make a comparison is to convert the energy the 'heat pump' uses [kWh] to btu/h. (3413 btu/h per kWh). Then compare the amount of btu/h energy delivered to the occupied space. This is representative of the COP. [A heat pump with a COP of say 2.0 has a 'coefficent' of 200% as compared to a electric strip heater of the same capacity.] Keep in mind though, that when the conditions change [outdoor temp's] the COP decreases as well as the capacity delivered. On the other hand, a natural gas furnace delivers the same btu/h no matter what the outdoor temperature is. But, is either 80% efficient or 90% - 93% depending on the model. The remainder of the which goes up the flu stack. When you compare $ for $ [which if you ask, I will be happy to send you a power point presentation based on the costs associated with different energy sources and different uses] you would find a heat pump actually is just as effient as a gas fired heater, Nonsequitor. That's like saying the moon is as low as water - it simply doesn't make any sense at all, it's gibberish. What you meant to say was 'cost effective'. This can only be computed when fuel costs are known and stated ( gas v oil v electricity ). provided it doesn't reach a low COP [low outdoor temp's]. This 'higher efficency' state only occurrs around 70º F ambient. Oh, ****ing bull****. WTF are you talking about ? You're supposing someone runs their heat pump in heat mode when it's 70 outside ??? And that's the 'only' time heat pumps make economic sense ??? Bull****. Nonsense. When the temp. outside drops to 50º F the COP really starts to take a dive and the gas fired furnace becomes the winner. [More efficent.] Bzzt. Wrong. At ANY temp above the economic balance point, a heat pump will continue to provide cheaper heat, IE, 'more heat energy out of it than you put electrical ( source ) energy into it '. IOW - even at 30 F or less, a heat pump continues to provide economical heat. Now, it may very well not provide *ALL* the heat you need at that point, but what heat it DOES provide is less expensive than anything else, such as fuel-fired, etc, *IF* the fuel costs made sense to begin with. The economic balance point is derived from the cost of fuels and electricity at the time. In areas with high gas/oil costs and low KW costs, it makes sense. In areas with high KW costs and low oil/gas costs, it does not. The time to consider a heat pump is when other fuels are either expensive, or unavailable. I hope this is helpful. Misleading in it's bulk. You started of with a few simple facts that you got right, but then you ****ed up completely. If you're going to give advice on a subject, you should study it and understand it first. Paul ( pjm @ pobox . com ) - remove spaces to email me 'Some days, it's just not worth chewing through the restraints.' HVAC/R program for Palm PDA's Free demo now available online http://pmilligan.net/palm/ Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/ |
On 20 Feb 2005 18:18:40 -0800, wrote:
Here's another rule of thumb: "Around 37 F many heat pumps reach what is called the balance point. At or near this temperature the heat pump needs to run constantly to produce enough heat to maintain a comfortable indoor temperature." http://www.askthebuilder.com/294_Hea...ey_Work_.shtml That is also bull****. It is called the 'thermal balance point' ( as opposed to the *economic* balance point I referred to earlier ), and it ENTIRELY depends on the size of the equipment, in relation to the load. Given 2 identical houses, side by side, one with a 3 ton heat pump and one with a 10 ton heat pump, the outdoor temperature where the 3 ton can 'barely keep up' will be very different ( higher ) than the temperature whre the 10 ton system can barely keep up. In either event, below the 'thermal balance point', the heat pump is STILL putting out economical heat into the house, it simply needs another source to add MORE heat. Paul ( pjm @ pobox . com ) - remove spaces to email me 'Some days, it's just not worth chewing through the restraints.' HVAC/R program for Palm PDA's Free demo now available online http://pmilligan.net/palm/ Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/ |
A software company :-)
On 20 Feb 2005 22:46:35 EST, Vicki Szaszvari wrote: What is symantics? Zyp wrote: Paul; Then give the advice. If you are so bent on being the perfectionist.... I tried to answer it as simply as possible. And your correct [symantics.] But that's fine. Like I said you are obviously bent on putting other's down. All of your posts are either telling someone to get the **** out or someone's wrong in their posting. I haven't truly seen anything positive from your end. I don't have to put up with your bull either. I can just troll .... Zyp p j m@see _my _sig _for_address.com wrote in message ... On Sun, 20 Feb 2005 13:34:25 -0800, "Zyp" wrote: John; This may be a bit lengthy but I'll try to explain as breifly as possible. The only way you can compare one unit to another [efficiency] is work in the same language. In other words, heat [btu/h]. Capacity vs. energy consumed. To relate, a heat pump is measured in HSPF [Heating Seasonal Performance Factor] and COP [Coefficient of Performance.] Both have relationship [ratio] between the energy consumed vs. heat energy delivered. A furnace on the other hand consumes natural gas or propane gas and delivers heat energy vs. energy consumed and has a specifiec amount of waster AFUE [American Fuel Utilization Efficienty] The easiest way to make a comparison is to convert the energy the 'heat pump' uses [kWh] to btu/h. (3413 btu/h per kWh). Then compare the amount of btu/h energy delivered to the occupied space. This is representative of the COP. [A heat pump with a COP of say 2.0 has a 'coefficent' of 200% as compared to a electric strip heater of the same capacity.] Keep in mind though, that when the conditions change [outdoor temp's] the COP decreases as well as the capacity delivered. On the other hand, a natural gas furnace delivers the same btu/h no matter what the outdoor temperature is. But, is either 80% efficient or 90% - 93% depending on the model. The remainder of the which goes up the flu stack. When you compare $ for $ [which if you ask, I will be happy to send you a power point presentation based on the costs associated with different energy sources and different uses] you would find a heat pump actually is just as effient as a gas fired heater, Nonsequitor. That's like saying the moon is as low as water - it simply doesn't make any sense at all, it's gibberish. What you meant to say was 'cost effective'. This can only be computed when fuel costs are known and stated ( gas v oil v electricity ). provided it doesn't reach a low COP [low outdoor temp's]. This 'higher efficency' state only occurrs around 70º F ambient. Oh, ****ing bull****. WTF are you talking about ? You're supposing someone runs their heat pump in heat mode when it's 70 outside ??? And that's the 'only' time heat pumps make economic sense ??? Bull****. Nonsense. When the temp. outside drops to 50º F the COP really starts to take a dive and the gas fired furnace becomes the winner. [More efficent.] Bzzt. Wrong. At ANY temp above the economic balance point, a heat pump will continue to provide cheaper heat, IE, 'more heat energy out of it than you put electrical ( source ) energy into it '. IOW - even at 30 F or less, a heat pump continues to provide economical heat. Now, it may very well not provide *ALL* the heat you need at that point, but what heat it DOES provide is less expensive than anything else, such as fuel-fired, etc, *IF* the fuel costs made sense to begin with. The economic balance point is derived from the cost of fuels and electricity at the time. In areas with high gas/oil costs and low KW costs, it makes sense. In areas with high KW costs and low oil/gas costs, it does not. The time to consider a heat pump is when other fuels are either expensive, or unavailable. I hope this is helpful. Misleading in it's bulk. You started of with a few simple facts that you got right, but then you ****ed up completely. If you're going to give advice on a subject, you should study it and understand it first. Paul ( pjm @ pobox . com ) - remove spaces to email me 'Some days, it's just not worth chewing through the restraints.' HVAC/R program for Palm PDA's Free demo now available online http://pmilligan.net/palm/ Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/ Paul ( pjm @ pobox . com ) - remove spaces to email me 'Some days, it's just not worth chewing through the restraints.' HVAC/R program for Palm PDA's Free demo now available online http://pmilligan.net/palm/ Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/ |
wrote in message ... So, how do things work when KGW is predicting the end of the world in the next ice storm, and it gets below 30F? 30 F usually aint bad at all...sized properly, heat pumps generally work fine in that temp. But, this doesnt really belong on alt hvac, so best would be to take it offline as I dont follow the other groups you are crossposting posting to.....feel free to email me for more info if you like--my email address is good. -- SVL |
p j m@see _my _sig _for_address.com wrote in message ... Given 2 identical houses, side by side, one with a 3 ton heat pump and one with a 10 ton heat pump, the outdoor temperature where the 3 ton can 'barely keep up' will be very different ( higher ) than the temperature whre the 10 ton system can barely keep up. In either event, below the 'thermal balance point', the heat pump is STILL putting out economical heat into the house, it simply needs another source to add MORE heat. IOW, on heating...for the most part, the steep drop-off is in *capacity*, not *efficiency* when the outdoor ambient temp swings low..... Why is this difficult for so many folks ??? -- SVL |
Mine, too, if that's SYMANTEC. With that nice-looking Peter Norton on
the boxfor years! Not "symantics." Noon-Air wrote: Thats the folks what do my anti-virus software ;-) "Vicki Szaszvari" wrote in message ... What is symantics? Zyp wrote: Paul; Then give the advice. If you are so bent on being the perfectionist.... I tried to answer it as simply as possible. And your correct [symantics.] But that's fine. Like I said you are obviously bent on putting other's down. All of your posts are either telling someone to get the **** out or someone's wrong in their posting. I haven't truly seen anything positive from your end. I don't have to put up with your bull either. I can just troll .... Zyp p j m@see _my _sig _for_address.com wrote in message ... On Sun, 20 Feb 2005 13:34:25 -0800, "Zyp" wrote: John; This may be a bit lengthy but I'll try to explain as breifly as possible. The only way you can compare one unit to another [efficiency] is work in the same language. In other words, heat [btu/h]. Capacity vs. energy consumed. To relate, a heat pump is measured in HSPF [Heating Seasonal Performance Factor] and COP [Coefficient of Performance.] Both have relationship [ratio] between the energy consumed vs. heat energy delivered. A furnace on the other hand consumes natural gas or propane gas and delivers heat energy vs. energy consumed and has a specifiec amount of waster AFUE [American Fuel Utilization Efficienty] The easiest way to make a comparison is to convert the energy the 'heat pump' uses [kWh] to btu/h. (3413 btu/h per kWh). Then compare the amount of btu/h energy delivered to the occupied space. This is representative of the COP. [A heat pump with a COP of say 2.0 has a 'coefficent' of 200% as compared to a electric strip heater of the same capacity.] Keep in mind though, that when the conditions change [outdoor temp's] the COP decreases as well as the capacity delivered. On the other hand, a natural gas furnace delivers the same btu/h no matter what the outdoor temperature is. But, is either 80% efficient or 90% - 93% depending on the model. The remainder of the which goes up the flu stack. When you compare $ for $ [which if you ask, I will be happy to send you a power point presentation based on the costs associated with different energy sources and different uses] you would find a heat pump actually is just as effient as a gas fired heater, Nonsequitor. That's like saying the moon is as low as water - it simply doesn't make any sense at all, it's gibberish. What you meant to say was 'cost effective'. This can only be computed when fuel costs are known and stated ( gas v oil v electricity ). provided it doesn't reach a low COP [low outdoor temp's]. This 'higher efficency' state only occurrs around 70º F ambient. Oh, ****ing bull****. WTF are you talking about ? You're supposing someone runs their heat pump in heat mode when it's 70 outside ??? And that's the 'only' time heat pumps make economic sense ??? Bull****. Nonsense. When the temp. outside drops to 50º F the COP really starts to take a dive and the gas fired furnace becomes the winner. [More efficent.] Bzzt. Wrong. At ANY temp above the economic balance point, a heat pump will continue to provide cheaper heat, IE, 'more heat energy out of it than you put electrical ( source ) energy into it '. IOW - even at 30 F or less, a heat pump continues to provide economical heat. Now, it may very well not provide *ALL* the heat you need at that point, but what heat it DOES provide is less expensive than anything else, such as fuel-fired, etc, *IF* the fuel costs made sense to begin with. The economic balance point is derived from the cost of fuels and electricity at the time. In areas with high gas/oil costs and low KW costs, it makes sense. In areas with high KW costs and low oil/gas costs, it does not. The time to consider a heat pump is when other fuels are either expensive, or unavailable. I hope this is helpful. Misleading in it's bulk. You started of with a few simple facts that you got right, but then you ****ed up completely. If you're going to give advice on a subject, you should study it and understand it first. Paul ( pjm @ pobox . com ) - remove spaces to email me 'Some days, it's just not worth chewing through the restraints.' HVAC/R program for Palm PDA's Free demo now available online http://pmilligan.net/palm/ Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/ |
OK, maybe 'symantics' is 'pretend shenanigans' :-)
Work on it, folks, work on it :-) On 20 Feb 2005 23:52:35 EST, Vicki Szaszvari wrote: Mine, too, if that's SYMANTEC. With that nice-looking Peter Norton on the boxfor years! Not "symantics." Noon-Air wrote: Thats the folks what do my anti-virus software ;-) "Vicki Szaszvari" wrote in message ... What is symantics? Zyp wrote: Paul; Then give the advice. If you are so bent on being the perfectionist.... I tried to answer it as simply as possible. And your correct [symantics.] But that's fine. Like I said you are obviously bent on putting other's down. All of your posts are either telling someone to get the **** out or someone's wrong in their posting. I haven't truly seen anything positive from your end. I don't have to put up with your bull either. I can just troll .... Zyp p j m@see _my _sig _for_address.com wrote in message m... On Sun, 20 Feb 2005 13:34:25 -0800, "Zyp" wrote: John; This may be a bit lengthy but I'll try to explain as breifly as possible. The only way you can compare one unit to another [efficiency] is work in the same language. In other words, heat [btu/h]. Capacity vs. energy consumed. To relate, a heat pump is measured in HSPF [Heating Seasonal Performance Factor] and COP [Coefficient of Performance.] Both have relationship [ratio] between the energy consumed vs. heat energy delivered. A furnace on the other hand consumes natural gas or propane gas and delivers heat energy vs. energy consumed and has a specifiec amount of waster AFUE [American Fuel Utilization Efficienty] The easiest way to make a comparison is to convert the energy the 'heat pump' uses [kWh] to btu/h. (3413 btu/h per kWh). Then compare the amount of btu/h energy delivered to the occupied space. This is representative of the COP. [A heat pump with a COP of say 2.0 has a 'coefficent' of 200% as compared to a electric strip heater of the same capacity.] Keep in mind though, that when the conditions change [outdoor temp's] the COP decreases as well as the capacity delivered. On the other hand, a natural gas furnace delivers the same btu/h no matter what the outdoor temperature is. But, is either 80% efficient or 90% - 93% depending on the model. The remainder of the which goes up the flu stack. When you compare $ for $ [which if you ask, I will be happy to send you a power point presentation based on the costs associated with different energy sources and different uses] you would find a heat pump actually is just as effient as a gas fired heater, Nonsequitor. That's like saying the moon is as low as water - it simply doesn't make any sense at all, it's gibberish. What you meant to say was 'cost effective'. This can only be computed when fuel costs are known and stated ( gas v oil v electricity ). provided it doesn't reach a low COP [low outdoor temp's]. This 'higher efficency' state only occurrs around 70º F ambient. Oh, ****ing bull****. WTF are you talking about ? You're supposing someone runs their heat pump in heat mode when it's 70 outside ??? And that's the 'only' time heat pumps make economic sense ??? Bull****. Nonsense. When the temp. outside drops to 50º F the COP really starts to take a dive and the gas fired furnace becomes the winner. [More efficent.] Bzzt. Wrong. At ANY temp above the economic balance point, a heat pump will continue to provide cheaper heat, IE, 'more heat energy out of it than you put electrical ( source ) energy into it '. IOW - even at 30 F or less, a heat pump continues to provide economical heat. Now, it may very well not provide *ALL* the heat you need at that point, but what heat it DOES provide is less expensive than anything else, such as fuel-fired, etc, *IF* the fuel costs made sense to begin with. The economic balance point is derived from the cost of fuels and electricity at the time. In areas with high gas/oil costs and low KW costs, it makes sense. In areas with high KW costs and low oil/gas costs, it does not. The time to consider a heat pump is when other fuels are either expensive, or unavailable. I hope this is helpful. Misleading in it's bulk. You started of with a few simple facts that you got right, but then you ****ed up completely. If you're going to give advice on a subject, you should study it and understand it first. Paul ( pjm @ pobox . com ) - remove spaces to email me 'Some days, it's just not worth chewing through the restraints.' HVAC/R program for Palm PDA's Free demo now available online http://pmilligan.net/palm/ Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/ Paul ( pjm @ pobox . com ) - remove spaces to email me 'Some days, it's just not worth chewing through the restraints.' HVAC/R program for Palm PDA's Free demo now available online http://pmilligan.net/palm/ Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/ |
1 Attachment(s)
That's how they spelt it in the "old ways".
Here's how the college edjikated people spell it: 3 entries found for semantics. To select an entry, click on it. semanticsgeneral semanticsgenerative semantics Main Entry: se·man·tics Pronunciation: si-'man-tiks Function: noun plural but singular or plural in construction 1 : the study of meanings: a : the historical and psychological study and the classification of changes in the signification of words or forms viewed as factors in linguistic development b (1) : SEMIOTIC (2) : a branch of semiotic dealing with the relations between signs and what they refer to and including theories of denotation, extension, naming, and truth 2 : GENERAL SEMANTICS 3 a : the meaning or relationship of meanings of a sign or set of signs; especially : connotative meaning b : the language used (as in advertising or political propaganda) to achieve a desired effect on an audience especially through the use of words with novel or dual meanings "Vicki Szaszvari" wrote in message ... What is symantics? Zyp wrote: Paul; Then give the advice. If you are so bent on being the perfectionist.... I tried to answer it as simply as possible. And your correct [symantics.] But that's fine. Like I said you are obviously bent on putting other's down. All of your posts are either telling someone to get the **** out or someone's wrong in their posting. I haven't truly seen anything positive from your end. I don't have to put up with your bull either. I can just troll .... Zyp p j m@see _my _sig _for_address.com wrote in message ... On Sun, 20 Feb 2005 13:34:25 -0800, "Zyp" wrote: John; This may be a bit lengthy but I'll try to explain as breifly as possible. The only way you can compare one unit to another [efficiency] is work in the same language. In other words, heat [btu/h]. Capacity vs. energy consumed. To relate, a heat pump is measured in HSPF [Heating Seasonal Performance Factor] and COP [Coefficient of Performance.] Both have relationship [ratio] between the energy consumed vs. heat energy delivered. A furnace on the other hand consumes natural gas or propane gas and delivers heat energy vs. energy consumed and has a specifiec amount of waster AFUE [American Fuel Utilization Efficienty] The easiest way to make a comparison is to convert the energy the 'heat pump' uses [kWh] to btu/h. (3413 btu/h per kWh). Then compare the amount of btu/h energy delivered to the occupied space. This is representative of the COP. [A heat pump with a COP of say 2.0 has a 'coefficent' of 200% as compared to a electric strip heater of the same capacity.] Keep in mind though, that when the conditions change [outdoor temp's] the COP decreases as well as the capacity delivered. On the other hand, a natural gas furnace delivers the same btu/h no matter what the outdoor temperature is. But, is either 80% efficient or 90% - 93% depending on the model. The remainder of the which goes up the flu stack. When you compare $ for $ [which if you ask, I will be happy to send you a power point presentation based on the costs associated with different energy sources and different uses] you would find a heat pump actually is just as effient as a gas fired heater, Nonsequitor. That's like saying the moon is as low as water - it simply doesn't make any sense at all, it's gibberish. What you meant to say was 'cost effective'. This can only be computed when fuel costs are known and stated ( gas v oil v electricity ). provided it doesn't reach a low COP [low outdoor temp's]. This 'higher efficency' state only occurrs around 70º F ambient. Oh, ****ing bull****. WTF are you talking about ? You're supposing someone runs their heat pump in heat mode when it's 70 outside ??? And that's the 'only' time heat pumps make economic sense ??? Bull****. Nonsense. When the temp. outside drops to 50º F the COP really starts to take a dive and the gas fired furnace becomes the winner. [More efficent.] Bzzt. Wrong. At ANY temp above the economic balance point, a heat pump will continue to provide cheaper heat, IE, 'more heat energy out of it than you put electrical ( source ) energy into it '. IOW - even at 30 F or less, a heat pump continues to provide economical heat. Now, it may very well not provide *ALL* the heat you need at that point, but what heat it DOES provide is less expensive than anything else, such as fuel-fired, etc, *IF* the fuel costs made sense to begin with. The economic balance point is derived from the cost of fuels and electricity at the time. In areas with high gas/oil costs and low KW costs, it makes sense. In areas with high KW costs and low oil/gas costs, it does not. The time to consider a heat pump is when other fuels are either expensive, or unavailable. I hope this is helpful. Misleading in it's bulk. You started of with a few simple facts that you got right, but then you ****ed up completely. If you're going to give advice on a subject, you should study it and understand it first. Paul ( pjm @ pobox . com ) - remove spaces to email me 'Some days, it's just not worth chewing through the restraints.' HVAC/R program for Palm PDA's Free demo now available online http://pmilligan.net/palm/ Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/ |
|
PrecisionMachinisT wrote:
p j m@see _my _sig _for_address.com wrote in message ... Given 2 identical houses, side by side, one with a 3 ton heat pump and one with a 10 ton heat pump, the outdoor temperature where the 3 ton can 'barely keep up' will be very different ( higher ) than the temperature whre the 10 ton system can barely keep up. In either event, below the 'thermal balance point', the heat pump is STILL putting out economical heat into the house, it simply needs another source to add MORE heat. IOW, on heating...for the most part, the steep drop-off is in *capacity*, not *efficiency* when the outdoor ambient temp swings low..... Why is this difficult for so many folks ??? Would you guys say that if a HP system is oversized, the COP can fall enough that the economic balance point is reached, even though the reduction in capacity isn't enough to hit the thermal balance point? %mod% |
On 21 Feb 2005 10:20:36 -0800, wrote:
PrecisionMachinisT wrote: p j m@see _my _sig _for_address.com wrote in message ... Given 2 identical houses, side by side, one with a 3 ton heat pump and one with a 10 ton heat pump, the outdoor temperature where the 3 ton can 'barely keep up' will be very different ( higher ) than the temperature whre the 10 ton system can barely keep up. In either event, below the 'thermal balance point', the heat pump is STILL putting out economical heat into the house, it simply needs another source to add MORE heat. IOW, on heating...for the most part, the steep drop-off is in *capacity*, not *efficiency* when the outdoor ambient temp swings low..... Why is this difficult for so many folks ??? Would you guys say that if a HP system is oversized, the COP can fall enough that the economic balance point is reached, even though the reduction in capacity isn't enough to hit the thermal balance point? %mod% Yep. Paul ( pjm @ pobox . com ) - remove spaces to email me 'Some days, it's just not worth chewing through the restraints.' HVAC/R program for Palm PDA's Free demo now available online http://pmilligan.net/palm/ Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/ |
p j m@see _my _sig _for_address.com wrote: On 21 Feb 2005 10:20:36 -0800, wrote: Would you guys say that if a HP system is oversized, the COP can fall enough that the economic balance point is reached, even though the reduction in capacity isn't enough to hit the thermal balance point? Yep. Well, if that's the case, then is the following true: "below the 'thermal balance point', the heat pump is STILL putting out economical heat into the house..." ? %mod% |
On 21 Feb 2005 12:12:59 -0800, wrote:
p j m@see _my _sig _for_address.com wrote: On 21 Feb 2005 10:20:36 -0800, wrote: Would you guys say that if a HP system is oversized, the COP can fall enough that the economic balance point is reached, even though the reduction in capacity isn't enough to hit the thermal balance point? Yep. Well, if that's the case, then is the following true: "below the 'thermal balance point', the heat pump is STILL putting out economical heat into the house..." ? %mod% Oh, yes, absolutely. The TBP is the point where the output of the heat pump is sufficient to maintain target temps inside ( regardless of cost ). The ECB is the point where the cost of getting a BTU out of the HP exceeds the cost of getting it from some other source ( gas / oil ). In theory, the ECB of a HP CAN NOT fall below unity ** as compared to electric strip heat **, IE, it will ALWAYS return at least 1 KW worth of heat for 1 KW of power to run it ( COP of 1 ). Paul ( pjm @ pobox . com ) - remove spaces to email me 'Some days, it's just not worth chewing through the restraints.' HVAC/R program for Palm PDA's Free demo now available online http://pmilligan.net/palm/ Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/ |
p j m@see _my _sig _for_address.com wrote:
Oh, yes, absolutely. The TBP is the point where the output of the heat pump is sufficient to maintain target temps inside ( regardless of cost ). The ECB is the point where the cost of getting a BTU out of the HP exceeds the cost of getting it from some other source ( gas / oil ). In theory, the ECB of a HP CAN NOT fall below unity ** as compared to electric strip heat **, IE, it will ALWAYS return at least 1 KW worth of heat for 1 KW of power to run it ( COP of 1 ). Well agreed on the last point. However if the alternative source is gas/oil, the EBP will be reached well before the COP falls close to 1. Right? And if the HP is sized so that it can maintain design temp even below the EBP, then it seems clear that as outdoor temperature drops, further increase in heat loss simultaneous with reduction in capacity to reach the TBP, could only result in the cost of electric HP heat exceeding gas/oil at the TBP. So I'd say that the statement "below the 'thermal balance point', the heat pump is STILL putting out economical heat into the house" depends on 1) alternate heat is resistive strips, such that the EBP cannot ever realistically be reached - OR - 2) the TBP is above the EBP, and the presence of an EBP implies fossil fuel alternate heat source; in this case, the HP would never be run below the EBP because the fossil source would have taken over. I could see how either 1 or 2 could apply to almost all real world scenarios, except for gross oversizing. When I was at my neighbor's diagnosing an (unrelated) electrical problem, I discovered his HP can maintain 67F indoors with 17F outdoors with the outdoor unit fan not running (burnt out). His COP can't be that great in that situation, certainly not as high as 2. It was installed in 1978, oil backup. He's on his 2nd tank of oil since installation. His HP is on a separate meter. This underscores the point that the EBP is tied to the rates of both electricity and the alternate fuel. That can change day-to-day, even hour-to-hour because of demand metering. %mod% |
On 21 Feb 2005 14:28:33 -0800, wrote:
p j m@see _my _sig _for_address.com wrote: Oh, yes, absolutely. The TBP is the point where the output of the heat pump is sufficient to maintain target temps inside ( regardless of cost ). The ECB is the point where the cost of getting a BTU out of the HP exceeds the cost of getting it from some other source ( gas / oil ). In theory, the ECB of a HP CAN NOT fall below unity ** as compared to electric strip heat **, IE, it will ALWAYS return at least 1 KW worth of heat for 1 KW of power to run it ( COP of 1 ). Well agreed on the last point. However if the alternative source is gas/oil, the EBP will be reached well before the COP falls close to 1. Right? Very likely, but of course depending on the cost of each fuel source, and the efficiency of the furnace in question. At a practical 'real world' level - 'yes'. And if the HP is sized so that it can maintain design temp even below the EBP, then it seems clear that as outdoor temperature drops, further increase in heat loss simultaneous with reduction in capacity to reach the TBP, could only result in the cost of electric HP heat exceeding gas/oil at the TBP. Yes, exactly. More importantly, proper heat pump sizing is mainly oriented towards COOLING needs, where SHR ( sensible heat ratio ), IE, latent heat removal, is so important. By general concept, heat pumps are most effective where it is warmer. Thus, in context, cooling season is going to be a dominant concern. Thus, moisture removal is critical to proper system design. Thus, oversizing ( such as to provide more heat during the lesser heating season, at the expense of proper moisture removal in summer ) is not advised. In an area that is so dominantly cold rather than hot, heat pumps make a lot less sense, if any. In areas where it is dominantly hot, heat pumps should be sized as AC units, with AC needs in mind. So I'd say that the statement "below the 'thermal balance point', the heat pump is STILL putting out economical heat into the house" depends on 1) alternate heat is resistive strips, such that the EBP cannot ever realistically be reached - OR - 2) the TBP is above the EBP, and the presence of an EBP implies fossil fuel alternate heat source; in this case, the HP would never be run below the EBP because the fossil source would have taken over. Close, not quite cigar material. The HP can still be contributing economically effective heat below it's TBP, even if the TBP is below the EBP. Then again, this is likely to be splitting hairs - if it's *****ing* cold out, you need some *real* heat ! :-) My own system as case in point - when it gets ~ 35 outside, the HP can't keep up, and the strips kick in as stage 2. But I let the HP continue to run, because THOSE BTU's are still costing me less than the ones coming from the strip heat. IE, below TBP, above EBP. At much less than ~ 25, I get tired of hearing the fan run all the time and the cost difference is so minor, so I just go to plain strip heat. Below ~ 17, I need BOTH to maintain temps - neither one by itself is enough. The HP is STILL adding BTU's, very very noticabley and measurably, but not at as much savings if any below the strip heat. But the strip heat by itself won't keep up. When I was at my neighbor's diagnosing an (unrelated) electrical problem, I discovered his HP can maintain 67F indoors with 17F outdoors with the outdoor unit fan not running (burnt out). That's rough :-) The outdoor fan is how the HP accumualtes heat to be moved inside ...... without it - you got squat. His COP can't be that great in that situation, certainly not as high as 2. It was installed in 1978, oil backup. He's on his 2nd tank of oil since installation. Tell him to invest in a fixed fan :-) Paul ( pjm @ pobox . com ) - remove spaces to email me 'Some days, it's just not worth chewing through the restraints.' HVAC/R program for Palm PDA's Free demo now available online http://pmilligan.net/palm/ Free Temperature / Pressure charts for 38 Ref's http://pmilligan.net/pmtherm/ |
When I was at my neighbor's diagnosing an (unrelated) electrical
problem, I discovered his HP can maintain 67F indoors with 17F outdoors with the outdoor unit fan not running (burnt out). That's rough :-) The outdoor fan is how the HP accumualtes heat to be moved inside ...... without it - you got squat. His COP can't be that great in that situation, certainly not as high as 2. It was installed in 1978, oil backup. He's on his 2nd tank of oil since installation. Tell him to invest in a fixed fan :-) Ok, Paul, you got me here. I thought I understood heat pumps but what's this about 'accumulates' heat. I guess I always thought when the RV kicked in, the evap was being used as a condenser and the vice versa. If this not true?... except that the metering device is still on the ID coil. FWIW, here in Indiana I see very few people with commercial HP's who are happy with them. Our office has them and I'm not happy with them there. Seems like they run far too hard, and the service life is about 10 years tops (Carrier) and the strips run a lot of the time anyhow. Might have just been a bad application for me... overhead doors opening and closing, pedestrian doors opening and closing, etc. I'm convinced in a good, tight home it may be a good idea here, but in commercial, I'm skeptical. We have Carrier here at home NG with straight AC, and it works well. Jake |
"Jake" wrote in message news:VNuSd.15105$g44.614@attbi_s54... When I was at my neighbor's diagnosing an (unrelated) electrical problem, I discovered his HP can maintain 67F indoors with 17F outdoors with the outdoor unit fan not running (burnt out). That's rough :-) The outdoor fan is how the HP accumualtes heat to be moved inside ...... without it - you got squat. His COP can't be that great in that situation, certainly not as high as 2. It was installed in 1978, oil backup. He's on his 2nd tank of oil since installation. Tell him to invest in a fixed fan :-) Ok, Paul, you got me here. I thought I understood heat pumps but what's this about 'accumulates' heat. I guess I always thought when the RV kicked in, the evap was being used as a condenser and the vice versa. If this not true?... except that the metering device is still on the ID coil. FWIW, here in Indiana I see very few people with commercial HP's who are happy with them. Our office has them and I'm not happy with them there. Seems like they run far too hard, and the service life is about 10 years tops (Carrier) and the strips run a lot of the time anyhow. Might have just been a bad application for me... overhead doors opening and closing, pedestrian doors opening and closing, etc. I'm convinced in a good, tight home it may be a good idea here, but in commercial, I'm skeptical. We have Carrier here at home NG with straight AC, and it works well. Jake You know, I'll bet your commercial application would work better if your building had more "thermal mass" to store the heat so that the temps would be less affected by doors opening, etc. More mass might help keep the strips from coming on as often (or as long). |
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posted for all of us....
He'd be all-electric except for fear of freezing during a blackout. Thus his I'm not arguing with you but what does he think his system is going to do during a power outage? -- Tekkie |
Tekkie wrote:
posted for all of us.... He'd be all-electric except for fear of freezing during a blackout. Thus his I'm not arguing with you but what does he think his system is going to do during a power outage? -- Tekkie It's a good point. The oil burner and air circulator do require electricity, after all. So there may be more to having the oil backup than fear of blackout. Fear of heatpump breakdown, maybe? Maybe the idea of economic balance point was explained to him when he bought the system, but he sees no need to switch to oil when it gets really cold outside, because his HP is so oversized it keeps his house warm enough anyway, cost of oil vs. electric be damned? The only straight story I can get from him is how old the system is and how he seems to like to save the oil for emergencies. My guess is if the power did go out for an extended time, I'd run a wire over to his house from my generator to run his system on oil to keep his pipes from freezing. Running the HP from a generator would require a much bigger generator. %mod% |
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