Go Back   EcoRenovator > Improvements > Geothermal & Heat Pumps
Advanced Search

Blog 60+ Home Energy Saving Tips Recent Posts Search Today's Posts Mark Forums Read

Thread Tools Display Modes
Prev Previous Post   Next Post Next
Old 07-11-14, 03:22 AM   #11
Supreme EcoRenovator
AC_Hacker's Avatar
Join Date: Mar 2009
Location: Portland, OR
Posts: 4,004
Thanks: 303
Thanked 723 Times in 534 Posts

Originally Posted by jeff5may View Post
...For the first version of a controller, I would like to use an uno. ...
Great, Radio Shack has them, about 8 blocks away...

Originally Posted by jeff5may View Post
I have a good question for you: what kind of data is the thing you will be controlling this unit with going to be sending and receiving? Switch states? readings of what frequency? Keep alive sgnals?
I hope I'm talking approximately the same language...

For the very simplest application, I want to control a water-to-water heat pump... heating only, no cooling.

What I can envision as the most basic function is:

1.) Delayed (1 min) startup at power-up, then...

2.) Look for a "heat-required" signal from a separate thermostat.

3.) If "heat-required" signal is FALSE, do nothing.

4.) If "heat-required" signal is TRUE, start the loop water pump 30 seconds before indoor loop water pump. During this time, monitor the temperature of the water at the output of the ground loop HX.

[* NOTE: The controller needs a minimum HX output temp variable, to be used to assure that the HX does not freeze. For now, I think it should be 37F. That could be tweaked later *]

If the HX output temp measures <= 37F, keep loop water pump running, and wait 10 minutes, then re-measure.

If HX output temp measures > 37F then...

[* NOTE: we need to build a fail safe into the system such that if a value or value range from a thermistor (or 1-wire) that would occur if the sensor failed or a sensor wire broke, the unit would shut down and issue an ERROR light *]

5.) Start indoor water pump, and run for 30 seconds. After 30 seconds...

6.) Start compressor.

7.) Run until "heat-required" signal is FALSE, then...

8.) Cut both compressor and outdoor loop pump.

9.) Continue running indoor loop pump another 5 (variable here?) minutes.

10.) Continue monitoring "heat-required" signal

This is the first cut, so I'm open to feedback.



I'm not an HVAC technician. In fact, I'm barely even a hacker...
AC_Hacker is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -5. The time now is 11:17 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Ad Management by RedTyger
Inactive Reminders By Icora Web Design