Hi all,
I have the Honeywell Vision Pro IAQ controlling a Tranquility 27 4 ton with 5 and 10 KW backup heat packs.  The system works great and our bills are very very low through this hard winter.  We are very happy with our geo purchase.

Now that I have owned the system through the first heating season, I am questioning some of the control logic with the t-stat and wondering if there is a better moustrap out there just made for geo.

I have kept the e-heat breakers shut down and the sytem has kept up niceley.  I do supplement heat with a wood stove when it's really cold, but I think it would have been able to keep up, but I am not 100% sure.  It's definately doing better that the estimated use I got at the proposal stage.

The stat has the outdoor temp sensor, so can set e-heat lockout above a programmable set point, but if I am away the house could go cold if there is a heat pump issue.

It seems all the stats really like to keep comfort as the primary goal, and economy as a secondary afterthought.  I would like economy to be primary.

Some logic I thought a Geo Stat should have:
1) only turns on the e-heat if the inside temp drop below set point more than "x" (adjustable) degrees? (say a 2 degree drop).  ie. it can't keep up.

2) does not turn on e-heat to return from a programmed set-backs unless inside temp does not rise within "y" (adjustable) minutes?  (say 30-60 minutes with no temp rise)

3) does not turn on e-heat during manual temp adjustements unless inside temp does not rise within "z" (adjustable) minutes?  (say 30-60 minutes with no temp rise)

I would like to turn my e-heat breakers back on and would like to have a stat that would be more intelligent in it's use of expensive e-heat and not just turn it on due to set point changes.  Only turn it on as a last ditch, I am loosing the battle here, type scenario.  As you would do if you were in control of the system.

I see tons of observations of unrealized gains in economy due to stats turning on e-heat willy nilly.  I true economy based logic t-stat would really help a lot of geo folks.  IMO.

Maybe someone has found a stat that does just this and could share.  Maybe there are some models that come close? 

Any thoughts or comments are greatly appreciated.

Thanks,
Chris

Posted By heatoftheearth on 14 Mar 2011 08:44 PM
Climatemaster's ATP32U03 will do all the things you are requesting. PM me if you need help locating one.

Posted By chrisbiker on 14 Mar 2011 03:24 PM
The stat has the outdoor temp sensor, so can set e-heat lockout above a programmable
set point, but if I am away the house could go cold if there is a heat pump issue.

Posted By Looby on 14 Mar 2011 10:26 PM

Posted By chrisbiker on 14 Mar 2011 03:24 PM
The stat has the outdoor temp sensor, so can set e-heat lockout above a programmable
set point, but if I am away the house could go cold if there is a heat pump issue.

Easy! Put the "outdoor" temp sensor indoors. That'll allow you to
lock out e-heat unless the indoor temperature falls dangerously
low (while you're away from the house), or just too chilly (when
you're at home).

IMO, outdoor temperature information is of no use whatsoever
for controlling a water-to-air geo system, so you might as well
keep the sensor busy doing something useful.

Posted By joe.ami on 15 Mar 2011 01:17 AM
Most times I have to remind myself that my "holy grail" is not everybodies.

Any idea who makes this stat for Climate Master and what the model number would be?

Posted By Looby on 15 Mar 2011 11:58 AM

...stage1, stage2, sweater, aux,

Looby