Cohousing-L Mailing List: Best Practices: Geothermal HVAC

[Sharon Villines (sharon]

Is there anyone out there who understand the best ways to utilize 
geothermal HVAC units with closed ground loops?

When we moved in our HVAC company said the most economical way to use 
the units was to set a temperature and leave it. You could program them 
to go up and down but because of the length of time it takes to change 
the temperatures, etc. it was better to keep them within some range. 
Because the air coming out of the vents is the same temperature as the 
earth (mine seems to measure 65 degrees winter and summer) the extra 
power used to circulate that air is the only cost.

Is that true? If that is true, what does the compressor do? Our units 
have electrical heaters that boost the temps in the winter but I 
thought the summer cooling was just air flow over water coils.

We have some members who want the CH HVAC set at 82 degrees which means 
with a temperature swing of 6 degrees, it goes 3 degrees higher or 
lower. This temperature in an enclosed place with no cross ventilation 
is not comfortable to inhabit so others don't use the dining room 
without turning down the thermostat several hours before. Fine for 
planned events but still discourages spontaneous uses. For meetings we 
turn it down to 74 although I'm not sure the actual temp ever gets that 
low.

This may be an issue on which we just have to vote on a CH temperature 
but I would like to find some research to establish a best practices. 
Of course the whole issue of conservation would be solved by not having 
a CH or not heating or cooling it but.... Hoping not to go there.

Sharon
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Sharon Villines
Takoma Village Cohousing, Washington DC
http://www.takomavillage.org