On 5/26/2012 12:38 AM, Jon Elson wrote:
Tom Gardner wrote:



I've heard about using propane. AND I've heard the new refrigerants are
similarly petro-based and flammable. Is there an energy savings?
Really, different refrigerants don't have vastly different properties
in respect to energy required to move X BTUs from temp 1 to temp 2.
There are differences, and Propane is a bit better, but the difference
is pretty small. I used to have a thermodynamic calculator program
where you entered all the parameters (temp 1, temp 2, heat load,
compressor displacement, and refrigerant) and it would calculate the
HP required. It did show Propane to be a bit better than R-22.
But, the possibility of a major leak indoors blowing my house up
for the small improvement in efficiency made it seem like a bad idea.

Now, the newer A/C units achieve all their higher efficiency through
other means. They often have variable-speed compressors, scroll
compressors are a bit more efficient than pistons and valves,
they almost all use thermal expansion valves instead of capillary
metering, and they have larger condenser cores so that the condensing
temperature is a lot lower. All of this helps improve the
efficiency. just cleaning out the condenser core with a garden
hose can reduce power consumption 20% or more, and of course can bring
a system back to life when it is packed with cottonwood fuzz.
I clean my condensers once a year, for sure.

So, if you think the secret of the high SEER ratings on newer units
is due to the refrigerant used, it is practically achieved DESPITE
the refrigerants they have to use due to the ozone problem.

Jon

I too keep the condenser clean and I'm thankful there aren't any
Cottonwoods around. I've only had a bad capacitor and a bad Schrader
valve so far in this Trane system.

Jon Elson wrote:
Tom Gardner wrote:



I've heard about using propane. AND I've heard the new refrigerants are
similarly petro-based and flammable. Is there an energy savings?
Really, different refrigerants don't have vastly different properties
in respect to energy required to move X BTUs from temp 1 to temp 2.
There are differences, and Propane is a bit better, but the difference
is pretty small. I used to have a thermodynamic calculator program
where you entered all the parameters (temp 1, temp 2, heat load,
compressor displacement, and refrigerant) and it would calculate the
HP required. It did show Propane to be a bit better than R-22.
But, the possibility of a major leak indoors blowing my house up
for the small improvement in efficiency made it seem like a bad idea.

Now, the newer A/C units achieve all their higher efficiency through
other means. They often have variable-speed compressors, scroll
compressors are a bit more efficient than pistons and valves,
they almost all use thermal expansion valves instead of capillary
metering, and they have larger condenser cores so that the condensing
temperature is a lot lower. All of this helps improve the
efficiency. just cleaning out the condenser core with a garden
hose can reduce power consumption 20% or more, and of course can bring
a system back to life when it is packed with cottonwood fuzz.
I clean my condensers once a year, for sure.

So, if you think the secret of the high SEER ratings on newer units
is due to the refrigerant used, it is practically achieved DESPITE
the refrigerants they have to use due to the ozone problem.

Jon


http://www.icorinternational.com/hotshot.html


try this.

Jon Elson wrote:
Tom Gardner wrote:



I was thinking of just replacing the refrigerant *IF* an energy savings
would justify it. The 40% they state is mighty attractive! My system
is in good shape and should last a little while yet. I sell to a HVAC
supply outfit and am able to purchase from them. I imagine I'll be
replacing the unit in a number of years so I'll keep abreast of what to
do and what to buy.
40%?? VERRRY unlikely. You can swap to Propane, it will improve
efficiency by MAYBE 5% or so. Not so good if you spring a leak in
the evaporator coil. Next time the A/C starts up, the furnace
blows apart like a grenade.

There may be some other mixtures that are also available as drop-in
replacements, but anybody that claims they can get a 40% efficiency
boost without changing anything else in the system is selling snake
oil!

Also, many home A/C systems, especially older ones, use capillary
tube metering, and any change in heat capacity, saturation curve
or liquid viscosity will end up throwing the metering of liquid
into the evaporator off. Well, of course, cap tube systems don't
really meter the liquid well except at one set of temperatures,
anyway. And, a system with a thermal expansion valve needs to
have the same fluid in the sensing bulb as the refrigerant, so
changing the refrig. in those systems can lead to major malfunctions.
The worst would be "slugging", where a huge load of liquid pools in
the evaporator and is then slugged into the compressor, possibly
destroying it the first time this happens.

Jon


http://www.icorinternational.com/hotshot.html

I have used this on several occasions and it works fine and is not
explosive.



John

On 5/26/2012 2:35 PM, john wrote:
Jon Elson wrote:
Tom Gardner wrote:



I was thinking of just replacing the refrigerant *IF* an energy savings
would justify it. The 40% they state is mighty attractive! My system
is in good shape and should last a little while yet. I sell to a HVAC
supply outfit and am able to purchase from them. I imagine I'll be
replacing the unit in a number of years so I'll keep abreast of what to
do and what to buy.
40%?? VERRRY unlikely. You can swap to Propane, it will improve
efficiency by MAYBE 5% or so. Not so good if you spring a leak in
the evaporator coil. Next time the A/C starts up, the furnace
blows apart like a grenade.

There may be some other mixtures that are also available as drop-in
replacements, but anybody that claims they can get a 40% efficiency
boost without changing anything else in the system is selling snake
oil!

Also, many home A/C systems, especially older ones, use capillary
tube metering, and any change in heat capacity, saturation curve
or liquid viscosity will end up throwing the metering of liquid
into the evaporator off. Well, of course, cap tube systems don't
really meter the liquid well except at one set of temperatures,
anyway. And, a system with a thermal expansion valve needs to
have the same fluid in the sensing bulb as the refrigerant, so
changing the refrig. in those systems can lead to major malfunctions.
The worst would be "slugging", where a huge load of liquid pools in
the evaporator and is then slugged into the compressor, possibly
destroying it the first time this happens.

Jon


http://www.icorinternational.com/hotshot.html

I have used this on several occasions and it works fine and is not
explosive.



John

In the case studies for their R-22 replacement they *DO* show a better
than 20% energy savings. And, it won't be affected by the upcoming ban.
This is well worth consideration!

Steve W. wrote:
wrote:
On Fri, 25 May 2012 05:54:58 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

On the R22 thing... switch to propane, if you're doing it yourself.

LPG works well in car a/c

Alan

Yep, right up until it goes BOOM... Oh and the minor point of it being
illegal in the US.

Here is a controlled test that is going to demonstrate just how safe
propane is. These guys are ones who tell you how safe it is and that
leaks aren't a problem.

http://www.youtube.com/watch?v=Djtow...hannel&list=UL


http://www.epa.gov/ozone/snap/refrigerants/hc-12a.html



Hydrocarbon refrigerants are so dangerous that pepsi and coke drink
machines run on it and loads of European fridges and air cons run on it