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Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
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#1
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Household programmable thermostat needed.
Looking for a thermostat that will allow the temp to be set up or
down temporarily, and after an interval, will reset to the pre-programmed temp. Also, to enable/disable the whole house fan, then also, after an interval, reset to programmed value. Not finding what I need on the internet, probably because I don't know what it's called or described. thanks gary |
#2
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Household programmable thermostat needed.
On 1/29/2015 11:08 PM, gary wrote:
Looking for a thermostat that will allow the temp to be set up or down temporarily, and after an interval, will reset to the pre-programmed temp. Also, to enable/disable the whole house fan, then also, after an interval, reset to programmed value. Not finding what I need on the internet, probably because I don't know what it's called or described. thanks gary Would be a reasonable DIY project for a microcontroller. BASIC Stamp, Propeller, Pic... |
#3
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Household programmable thermostat needed.
On 1/29/2015 11:37 PM, Richard wrote:
On 1/29/2015 11:08 PM, gary wrote: Looking for a thermostat that will allow the temp to be set up or down temporarily, and after an interval, will reset to the pre-programmed temp. Also, to enable/disable the whole house fan, then also, after an interval, reset to programmed value. Not finding what I need on the internet, probably because I don't know what it's called or described. thanks gary Would be a reasonable DIY project for a microcontroller. BASIC Stamp, Propeller, Pic... One thing you don't want to do is break your HVAC system. There are timers and lockouts and etc. in there to keep the system from hurting itself. One way to get started is to use a heater coupled to the thermostat temperature sensor. Resistor or light bulb stuffed inside the housing near the sensor. You set the thermostat for the highest temperature you want. To get lower, you apply some heat to the sensor. Measure the actual temperature with your microcontroller and just drive the resistor when you want the temperature to go lower. That is minimally invasive and probably won't hurt your HVAC system no matter how often your program crashes ;-) You can even do warmer/colder with a Peltier device as the "heater". My favorite platform for this kind of thing is the Palm 3C PDA. Dirt cheap. You can program it in BASIC. Full GUI interface. I/O is an issue. You have one easily available input and one output at the serial port interface. I've used serial commands to drive a PIC processor that does the actual control interface when I needed more I/O. And if you step up to a more recent Palm, you can use bluetooth for wireless access. You can also use the IR interface as a serial communication port. The link is a prototype of a system that monitors a flapper on the heater vent, subtracts the delays to calculate the ON-time of the gas to the furnace and logs and plots that. http://i.imgur.com/vsaPixW.jpg You could certainly do this with a dedicated microcontroller, but this is dead simple. When I get up in the morning and turn on my PC, I can watch the gas furnace throttle down due to the extra heat from the computer. Was way cool for about a week. It did alert me when the furnace started acting up and the graph differed from the norm. Beware this stuff is addictive. You may soon find yourself building all manner of gadgets that you won't ever use. Guess that's the definition of "hobby". |
#4
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Household programmable thermostat needed.
"gary" wrote in message ...
Looking for a thermostat that will allow the temp to be set up or down temporarily, and after an interval, will reset to the pre-programmed temp. Also, to enable/disable the whole house fan, then also, after an interval, reset to programmed value. Not finding what I need on the internet, probably because I don't know what it's called or described. thanks gary ================================================== ===== The first part is standard on most programmable thermostats. In the US Honeywell seems to be the quality leader (IMHO), and readily available in the $50-100 range at Lowes and Home Depot. Usually you can program in 4 different temps per day, and either 5/2, or for a bit more $ 5/1/1 (5 days lumped together for Mon-Fri then either 2 together for the weekend or individual control over Sat and Sun). Once programmed and started you can manually adjust the set point up or down, and it will hold that new set point until the next time step in the program, when it will revert to the program. There is also a "Hold" button which lock in the manual adjustment until you explicitly release it and return to the programming. So, that is the first part you want, and most of the readily available brands work as I described. The problem is the fan control. I have not found any that allow control of the fan beyond the usual "auto" and "on" choices, where it comes on with the heat or cooling and goes back off when the temp set point is reached, or it is simply on forever until you go back to auto. I would really like to be able to program in say 15 minutes of fan every few hours, just to freshen up the air on those days or nights where the outside temp is close enough to the set point that the heat or cooling may only run once or twice in 8 hours, but I have never found a commercial unit that allows fan programming. Good luck, and if you find something please post it. Regards, Carl Ijames carl.ijames aat deletethis verizon dott net |
#5
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Household programmable thermostat needed.
On Thu, 29 Jan 2015 22:08:05 -0700, gary wrote:
Looking for a thermostat that will allow the temp to be set up or down temporarily, and after an interval, will reset to the pre-programmed temp. Also, to enable/disable the whole house fan, then also, after an interval, reset to programmed value. Not finding what I need on the internet, probably because I don't know what it's called or described. Here you go. WiFi thermostat on Amazon, "only" $283 and change. http://tinyurl.com/l4ck3qx Hook it up to the one WH and you're set. Oops, it's only 3000 watts. WHs are 4-9kW. How about this combo? http://tinyurl.com/qcz4atj controlled by this http://tinyurl.com/o34jbvq Be sure to set up alarms to tell you when you've been hacked. -- If more sane people were armed, crazy people would get off fewer shots. Support the 2nd Amendment |
#6
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Household programmable thermostat needed.
Hey Gary,
Not sure about ALL of what you request, but the bit about having a different setting for a limited period of time is what is used in buildings like a clubhouse. During the colder months, there is not a lot of activity, and the programmable thermostat is set at say 60 degrees, or even a scheduled program. If there is to be a random meeting held, there is a "button" that you push and it will raise the building to a preset programmable setting for say 2 hours (that's programmable too), and then return to the scheduled program. That is so nobody can forget to set the temp back when they leave after the meeting. I'm still trying to recall exactly what that button "says" on it, but something like "OVERRIDE" maybe ????? I'd suggest you pay a visit to an HVAC wholesale shop and describe what you require and see what they have. Take care. Brian Lawson, Bothwell, Ontario. XXXXXXXXXXXXXXXX On Thu, 29 Jan 2015 22:08:05 -0700, gary wrote: Looking for a thermostat that will allow the temp to be set up or down temporarily, and after an interval, will reset to the pre-programmed temp. Also, to enable/disable the whole house fan, then also, after an interval, reset to programmed value. Not finding what I need on the internet, probably because I don't know what it's called or described. thanks gary |
#7
Posted to rec.crafts.metalworking
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Household programmable thermostat needed.
On 1/29/2015 11:08 PM, gary wrote:
Looking for a thermostat that will allow the temp to be set up or down temporarily, and after an interval, will reset to the pre-programmed temp. Also, to enable/disable the whole house fan, then also, after an interval, reset to programmed value. Not finding what I need on the internet, probably because I don't know what it's called or described. thanks gary I see this as a pretty simple setup. Remember that most home thermostats have a 12 volt signal from a relay. Two thermostats set to different temperatures. A simple switch to select one thermostat's output, or the other would let you step up/down. But it could not handle the interval for the temporary change. So the micro (with a small relay output) is acting as the timer to change back. A button (MC) for "Temporary" would cause it to select the other thermostat. After the time ran out, it would change back to the first thermostat. Another switch (SPDT rather than button) could be used to decide it the system is supposed to be shut down for an interval, or just change temp. I suppose it wouldn't have to be a micro - if a mechanical timer could be found that can switch thermostats. A second mechanical timer could be wired to do the shutdown-for-a-while thing. All it has to do it not pass through the thermostat signal for a while... |
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