Programmable thermostats

[The Atomic Ass]

Lately I've become interested in these. My current central controller is just a digital thermostat only, no program ability.

But I also see a marked difference between running my space heater, and running my central, to keep the the temperature comfortable while above freezing. I use WAY less running the space heater above freezing. Below freezing, however, the space heater runs out of heat and I start losing temperature, thus needing to use the central, while the space heater basically stops cycling and runs constantly.

Then when it gets warm again, the space heater needs to be adjusted manually to prevent over-running up to obscene temps and bills.

Is there a programmable thermostat that will switch on and off a space heater while at warmer outside temps, and then, perhaps based on the duty cycle of the space heater, at some point decide to run the central, while still running the space heater so as to lower the cycling of the central? Or is this asking way too much?

[trikkonceptz]

I am not sure what you are asking for is possible. However, as a solution you may want to look into programmable air vents. Basically the air vent is run on a selonoid which has an independant programmable thermostat. This allows you to control air temps by room independantly by closing or opening specific vents in your house giving you room by room control.

This way if you run your central heat to just one room, it will reach the temp you desire much faster thus using less energy. It's ideal for homes where you need to cool specific areas like the TV room or bedroom at night, without having to keep the entire house at a specific tempertature.

[JMags]

You would probably have to build something like that. There are things called outdoor reset switches in the HVAC world that would give you a start though. Havn't drawn it out but I'm thinking something like breaking the circuit @ the central t-stat when above 32 and allowing @ the space heater and vise versa below temperature.

[The Atomic Ass]

Originally Posted by trikkonceptz

I am not sure what you are asking for is possible. However, as a solution you may want to look into programmable air vents. Basically the air vent is run on a selonoid which has an independant programmable thermostat. This allows you to control air temps by room independantly by closing or opening specific vents in your house giving you room by room control.

This way if you run your central heat to just one room, it will reach the temp you desire much faster thus using less energy. It's ideal for homes where you need to cool specific areas like the TV room or bedroom at night, without having to keep the entire house at a specific tempertature.

I'm already down to a single room, of a sorts. I'm in an apartment, and I've moved my bed out into the empty dining room, and so I just heat this area which is roughly 60% of the apartment.

I've been lucky the last few days, as I've stayed 2+ degrees above my central setpoint. But my space heater takes a lot of fiddling, as it tends to run away during the day, or on warmer days, and if it's set low when it gets cold, the central cycles prematurely. I should mention the space heater has a dumb thermostat.

[The Atomic Ass]

Ok, here's another idea. Are there any programmable thermostats that allow you to have both the A/C and heat activated at the same time? I was thinking have one heater, set on low setting, (~650 watts), be always on, UNLESS, the A/C triggers, flipping a DP relay, shutting it off, until the A/C portion clicked off, and restarted the heater...

Meanwhile, have the other heater, which has 1k and 1.5k watt settings, triggered via the heating portion. I figure setting the A/C portion for 62F, and the heat for 60F, to keep everything tightly controlled.

All of this would be completely independent of my central system, which is now shut off at the breaker. (It just flat out takes too much power, to the tune of 9kw, AND blows cold air for the first minute).

Thus far, manually triggering my 2 space heaters in an attempt to hold 60F has resulted in my power bill following the trend of the temperatures... Downward.

[Frank Lee]

Do ya just needta have something running at all times?

[The Atomic Ass]

Originally Posted by Frank Lee

Do ya just needta have something running at all times?

Ya' know what, I've got a clear picture in my head, but trying to explain it any clearer than that is pretty much hopeless with my limited grasp of the English language.

To attempt to clarify, in my idea, the thermostat's A/C set point would trigger a small relay, to shut OFF all the heat, should I reach an upper threshold. This is strictly heat-oriented, no actual Air Conditioning comes on when the set point is reached.

[wyatt]

I have heard of thermostats that plug into an outlet with a probe that goes inside a fridge, and you use it to keep beer fermenting at an "ideal" temp. You may be able to use something like that, but I have no idea what they are called or where to look... I guess google? ebay? amazon?

EDIT: Google search for Beer Fermenting Thermostat, 1st result
http://www.northernbrewer.com/temp-control.html
Looks like you plug in to the wall, and plug your fridge into it, use it to set the temp for the probe to kick on at. Not sure if it works for heating or just cooling, but you can look for more online also.

[Who]

What you need is a "2 stage thermostat" and a 24 volt relay. The thermostat would first "energize" your space heater via the 24 volt relay, and then when that can't maintain temp it would kick in the central heating. Normally these 2 stagers wouldn't be used with a space heater which is why you would need the relay to take the 24 volts from the t-stat and switch on the heater's regular electricty.

Honeywell, White-Rogers, tekmar et al make and sell them.

[MissileStick]

Could you close the central heating vents to the rooms you're not living in?

Also, it sounds like your space heater doesn't have a thermostat, but just a heat setting. A thermostat (by definition) is a device that turns on and off to maintain a given temperature. Would it be possible to get a space heater with a built-in thermostat? It sounds like that would solve your problems.