Computer based thermostat (DIY)

[bbrendon]

Shaky suggested I start a thread on non traditional thermostats. He has some input on some past experience and I'm starting down this road with this device.
http://cainetworks.com/products/webcontr...l-faq.html

[jkish]

I've always been interested in doing this, but it seemed to big a project for me to fit in at any point so far.

Are you doing zoning?

Have you seen this: http://www.homeclimatecontrol.com/

[bbrendon]

I've always been interested in doing this, but it seemed to big a project for me to fit in at any point so far.

Are you doing zoning?

Have you seen this: http://www.homeclimatecontrol.com/

I have not! Looks interesting. Unfortunately I'm not on Android so I wouldn't pursue it, but definitely looks like an option.

[jkish]

I have not! Looks interesting. Unfortunately I'm not on Android so I wouldn't pursue it, but definitely looks like an option.

I don't know what your plans are, but thought that the underlying controller might be of some interest since it already has control algorithms and support for various sensors and controls such as servo motors.

The basic controller looks like it runs on most Linux platforms.

[Shaky]

That Home Climate control link and the info on there looks very interesting. I'll be looking at that for sure for more ideas.

I don't have a lot of time to nicely detail out what I have done at the moment, but here's a rough summary of my setup:

Basically I have:
Elk controlling my Furnace(2-stage gas), and AC (single stage). My furnace is newer with a control board of it's own so has some smarts in it, although I've disabled some. Wish I had zone heating, but didn't know much about that when we built 7 years ago.

HVAC Interface:
Elk Relays (M1RB) are connected to the furnace to:
1x Relay - Turn AC ON/Off
1x Relay - Turn stage 1 Heat On/Off
1x Relay - Turn stage 2 Heat On/off
1x Relay - Turn fan to auto vs continuous mode
1x Relay - Control Humidity (future project)
1x Relay - Open Close Damper for Air to Air Exchanger (future project)

Temp Probes:
1x Elk Keypad temp
4 x VK-011 Temp sensors around house/ interface board tied to CQC
3 x Precon HS-200D for more temp sensors and Humidity tied to CQC

CQC:
RunTimer to track run times
Graphamatic to graph various heating/cooling stats
Datlog DB driver: track temps and relay on/off
Logic Server/Variables driver for logic inputs/outputs
Scheduled task: for Primary logic on Heat/Cooling calls (this should be a Macro\Driver some day if I ever get time)

The Elk has all the logic and safety controls built in and is capable of keeping the climate comfortable, but only uses the keypad for temp. input. I also have an old style thermostat hooked in parallel to the furnace. I set it to +5 Celcius (I'm in Canada) to make sure if both the Elk and CQC fail that the house wouldn't freeze if we were away in Winter.

I use CQC for fancier control with various logic to control things when it's up and running and use average room temp. from key locations to try and level things out. I hope one day to build in the ability to change which temp locations are used based on other inputs (like outside temps, time of year etc.) I think that would allow better cooling/heating to certain areas depending on other variables. If I were to build a house again I would go with zone heating, but the avg. temps scheme do help a lot for comfort. (just sacrifices some efficiency)

To keep things runnning if CQC were to fail I built a watchdog that if CQC fails to respond to the Elk for 5mins, the Elk takes over HVAC control.

I think that's it in a nutshell...it's always a work in progress and look forward to hearing more ideas and constructive feedback.

[bbrendon]

Wow. I had no idea HVAC could be so complex. My thermostat currently has two wires. When they touch the heat goes on. When they aren't touching, its off

In the shower this morning I was thinking about a more bullet-proof solution using arduino, but it's definitely out of my expertise.

...I'll see where the webcontrol board takes me and go from there.

[Dean Roddey]

There's also that Kyoko PLC that there's a driver for over in the beta drivers section. It might be something that could be addressed towards such a thing.

[Shaky]

Wow. I had no idea HVAC could be so complex. My thermostat currently has two wires. When they touch the heat goes on. When they aren't touching, its off

In the shower this morning I was thinking about a more bullet-proof solution using arduino, but it's definitely out of my expertise.

...I'll see where the webcontrol board takes me and go from there.

Haha, definitely the geekiest HVAC on my block...But not as complex as it sounds. The relays are just shorting the various wires to turn AC vs Heat off & On etc.

[rbroders]

The Koyo Click PLC is definitely an inexpensive programmable microcontroller with relay outputs. The only weakpoint for a thermostat system would be temperature inputs. Only one analog input is supported, but you could have CQC push the temperature into the Click from any source CQC can recognize.

Shaky, I recommend you check out my alternate runtimer: RunTimers2.
http://www.charmedquark.com/vb_forum/sho...hp?t=10514
It was explicitly designed for things like furnace run times. It provides a 24HR rolling total and also daily historical runtimes which can be displayed in a text list browser (I'm still waiting for a GraphListBrowser from Dean). With it, I can tell you that my hardest furnace day this year was 12/19 with a total of 7hr20min of runtime.

--Bob

[Shaky]

Shaky, I recommend you check out my alternate runtimer: RunTimers2.
--Bob

Thanks, downloading now and will give it a try.