Thermostat Question
April 1, 2004 5:43 PM Subscribe
Are there any programmable or automatic thermostats that can keep a house within a certain temperature range, and not just at a certain point? For example, I don't want to set the temperature at 72°F, but have the air conditioner come on at 73°F and the heater come on at 71°F. I'd prefer a range of six degrees or so, so that the air conditioner comes on if the temperature rises above 74°F, and the heater if it falls below 68°F, or something like that. I don't pay enough attention to it now, so the temperature swings too much and it's bad for items in the house. Can't some technology do this for me?
Response by poster: Yeah, I read that (in the PDF version), but it only talks about "set points" and programs to raise and lower the heat or cooling at specific times. It doesn't answer my question about a range of temperatures.
Thanks, though.
posted by mdeatherage at 10:22 PM on April 1, 2004
Thanks, though.
posted by mdeatherage at 10:22 PM on April 1, 2004
mdeatherage: Here's a better explanation. Almost any digital thermostat will allow you to create a "setback" schedule so that your house is (say) 65 degrees at night and 72 degrees during the day. Good ones let you do even more schedules to include mornings, evenings and weekends. Additionally you can generally tweak the current temperature until the next schedule change -- or set a permanent "hold".
In almost all cases the thermostat will have three overall settings: cool, heat, and off. In other words, it is either inoperative, or it's only operating one of the HVAC devices it's connected to. I suppose they might exist, but I doubt there are many that will operate as you posit in the post, turning on both devices at the opposite ends of the range you set. Usually they simply depend on the ambient outside temp to bring the house up or down until the appropriate device kicks in again. (It would be incredibly inefficient to have two devices working against each other. If your house is set up that way, it's likely the equipment was installed wrong.)
Really, they're cheap. Go to your local hardware store and get one. They're not that hard to hook up, either -- the main thing you need to do is watch the wires as you disassemble them (and tie the bundle off around a pencil first -- so it doesn't fall into the wall accidentally). Oh, and cut the power.
posted by dhartung at 11:24 PM on April 1, 2004
In almost all cases the thermostat will have three overall settings: cool, heat, and off. In other words, it is either inoperative, or it's only operating one of the HVAC devices it's connected to. I suppose they might exist, but I doubt there are many that will operate as you posit in the post, turning on both devices at the opposite ends of the range you set. Usually they simply depend on the ambient outside temp to bring the house up or down until the appropriate device kicks in again. (It would be incredibly inefficient to have two devices working against each other. If your house is set up that way, it's likely the equipment was installed wrong.)
Really, they're cheap. Go to your local hardware store and get one. They're not that hard to hook up, either -- the main thing you need to do is watch the wires as you disassemble them (and tie the bundle off around a pencil first -- so it doesn't fall into the wall accidentally). Oh, and cut the power.
posted by dhartung at 11:24 PM on April 1, 2004
Response by poster: I didn't mean to imply that the thermostat should turn on the heater and the air conditioner at the same time. I'm looking for one that will turn on the air conditioner when the temperature gets above (say) 74°F, or the heater when the temperature falls below 68°F. Since the temp can't be above 74° and below 68° at the same time, it should only run one device, no?
I saw several thermostats advertising heat-only or cool-only modes as a feature, saying the device "will not activate the heater or air conditioner unexpectedly," but that's exactly what I want it to do. I'm entering a two-month period (there will be another one in September-October) where the outside temperature will fluctuate between about 55°F and 85°F. When it gets warm in the afternoon, I have to go turn on the A/C or the temperature in the house gets into the high 70s. If I then don't remember to switch it back to heater at night, then overnight, the in-house temperature will fall to about 65°.
The swings are too much for things like keeping a piano in tune, and I'm looking for a way to fix that. What I do now effectively leaves all devices off much of the time, like by leaving the heater on set to 68° overnight and forgetting to set it back to A/C at 74°F during the afternoon. That often works well enough, but not always. If the temperature rises or falls too much, I want a little climate-controlled HVAC help without having to go home to the thermostat and ask for it.
Maybe what I want doesn't exist. That would make me sad.
posted by mdeatherage at 9:41 AM on April 2, 2004
I saw several thermostats advertising heat-only or cool-only modes as a feature, saying the device "will not activate the heater or air conditioner unexpectedly," but that's exactly what I want it to do. I'm entering a two-month period (there will be another one in September-October) where the outside temperature will fluctuate between about 55°F and 85°F. When it gets warm in the afternoon, I have to go turn on the A/C or the temperature in the house gets into the high 70s. If I then don't remember to switch it back to heater at night, then overnight, the in-house temperature will fall to about 65°.
The swings are too much for things like keeping a piano in tune, and I'm looking for a way to fix that. What I do now effectively leaves all devices off much of the time, like by leaving the heater on set to 68° overnight and forgetting to set it back to A/C at 74°F during the afternoon. That often works well enough, but not always. If the temperature rises or falls too much, I want a little climate-controlled HVAC help without having to go home to the thermostat and ask for it.
Maybe what I want doesn't exist. That would make me sad.
posted by mdeatherage at 9:41 AM on April 2, 2004
i don't know anything about the particular technolgy and american domestic writing, but in general terms what you want can be achieved with two thermostats - one controlling the heating and one the cooling. of course, that lets you set the to so that the ranges overlap, which would be a waste.
posted by andrew cooke at 10:09 AM on April 2, 2004
posted by andrew cooke at 10:09 AM on April 2, 2004
If you have a central forced air system which supplies both heating and cooling, you simply need a thermostat with an "auto" setting -- this will tell the system to provide heating or cooling as needed. It should have a setting which allows the amount of "swing" (i.e. 5 or 10 degrees, accuracy may vary) to be set. With a mixed system (e.g. forced air for cooling, hot water baseboard for heating), the controls can be installed to also allow an auto setting to function. This may be an elaborate enough change to require a heating and air-conditioning contractor.
Critical to its proper function in a mixed system is that your thermostat be properly placed to not give false reading and kick on the cooling while heat is being supplied to bring the temperature up. How old is your house? What systems are at work? Where is the thermostat? So many questions but solutions are always available -- cost is the big question as the solution becomes more complex.
Since it was mentioned, a piano is affected by humidity as well as temperature. Temperature works on the steel strings: I do not know how much they change with temperature (this information must be easily Google-able). Wood expands as it absorbs moisture, it contracts as it dries. Each species and cut of wood will express its own character and will also be related to its finish (as the finish allows more or less moisture to pass into the wood).
You can control humidity independent of temperature but it is potentially inefficient -- the process of dehumidifying adds heat to a space and the temperature may rise too high, require heat to be removed -- through cooling. You can have situations where heating and cooling are in effect being done at the same time to control humidity.
Temperature swings may effect the tuning of a piano but humidity changes are more damaging in the big picture (and to a big picture as well.)
posted by Dick Paris at 4:02 PM on April 2, 2004
Critical to its proper function in a mixed system is that your thermostat be properly placed to not give false reading and kick on the cooling while heat is being supplied to bring the temperature up. How old is your house? What systems are at work? Where is the thermostat? So many questions but solutions are always available -- cost is the big question as the solution becomes more complex.
Since it was mentioned, a piano is affected by humidity as well as temperature. Temperature works on the steel strings: I do not know how much they change with temperature (this information must be easily Google-able). Wood expands as it absorbs moisture, it contracts as it dries. Each species and cut of wood will express its own character and will also be related to its finish (as the finish allows more or less moisture to pass into the wood).
You can control humidity independent of temperature but it is potentially inefficient -- the process of dehumidifying adds heat to a space and the temperature may rise too high, require heat to be removed -- through cooling. You can have situations where heating and cooling are in effect being done at the same time to control humidity.
Temperature swings may effect the tuning of a piano but humidity changes are more damaging in the big picture (and to a big picture as well.)
posted by Dick Paris at 4:02 PM on April 2, 2004
I strongly suspect that what Andrew Cooke suggests is a bad idea unless you set the range to be considerably larger than the six degrees you mention. It would be interesting, though. Depending upon a bunch of different variables, the heating and cooling would be fighting each other—likely sometimes operating simultaneously—and the temp would regularly oscillate within a range.
Years ago, I built by hand a thermistor and relay assembly, connected to a microcomputer, and programmed it to control the heating—in the process, I thought a lot about what you're considering and realized that maintaining a set temperature via both heating and cooling is essentially a different problem than limiting a temperature extreme from a single direction. A regular thermostat can be a remarkably simple mechanical device. The thermostat you want cannot.
posted by Ethereal Bligh at 4:24 AM on April 3, 2004
Years ago, I built by hand a thermistor and relay assembly, connected to a microcomputer, and programmed it to control the heating—in the process, I thought a lot about what you're considering and realized that maintaining a set temperature via both heating and cooling is essentially a different problem than limiting a temperature extreme from a single direction. A regular thermostat can be a remarkably simple mechanical device. The thermostat you want cannot.
posted by Ethereal Bligh at 4:24 AM on April 3, 2004
For pianos you need humidity and heaters for your piano that are independent of the household hvac unless you have a highly controlled environmental system for your music room. I use the Dampp-Chaser system on my grand, with three rods spanned across the extent of the soundboard.
posted by bz at 7:59 PM on April 4, 2004
posted by bz at 7:59 PM on April 4, 2004
« Older I need a good photo or surface map of the Bermuda... | Windows Syncing Software for Website Backup, But... Newer »
This thread is closed to new comments.
posted by BlueTrain at 7:49 PM on April 1, 2004