Cohousing-L Mailing List: Re: Liveable temp/ geothermal

[katie-henry (katie-henry]

Chiming in from Eastern Village, and following up on Sharon's message. EVC had 
the same developer as TVC, and he evidently learned his lesson about low 
bidders because he went with the most expensive but most respected and 
experienced contractor in the DC area, and we have an excellent system to show 
for it.

As Sharon explained, in contrast to the TVC system, where each unit's heat pump 
is connected to a specific well, our wells (40 of them, each 600 feet deep) are 
all tied together and the water is circulated throughout the building by a 
large central pump. There is an additional small pump that injects water into 
the system to maintain pressure to compensate for normal water loss or a leak. 

Our heat pumps are from Florida Heat Pump. We're pretty satisfied with them. I 
don't have experience with other equipment, so can't compare. I think the 
equipment is a bit noisy. There is no question that it is a more comfortable 
form of heat and AC. 

Our developer bought an extended warranty (two years instead of one) on all of 
our mechanical equipment, which turned out to be a very good move. Most of our 
equipment failures took place during the second year, including a circuit board 
in the variable-speed pump controller that blew up because of a power outage 
and would have cost about $10,000 to replace.

We find our unit electric bills to be half or less compared to similar units in 
the multi-family building next door -- and they are doing everything humanly 
possible to reduce electricity usage, especially in summer, while we crank it 
up with gay abandon. If your electric bill is only $45, why not keep your 
apartment icy cold? We also benefit from our concrete bunker construction. Some 
of our surrounded units never have the heat come on at all in winter, even when 
the outside temp is below freezing. 

However, our maintenance and repair contract for the central circulating pump 
and the 16 CH heat pumps is with the very expensive specialist contractor who 
installed the equipment, and the cost gets passed on to the members in our HOA 
fees, so sometimes I wonder if we are really coming out ahead. 

As Robin pointed out, having geothermal means you don't need compressors. At 
EVC, if we had conventional split HVAC systems, we would have close to 100 
compressors churning away on the roof. Instead, we have a nice peaceful green 
roof with a gazebo and a playground.

One other point from our service guy: Geothermal systems are less efficient in 
winter than in summer. We definitely see that in our electric bills. We had an 
extreme cold spell last February or March and our CH electric bill spiked from 
about $2,400 to $3,500 because the emergency backup electric heat was kicking 
in. You don't see a lot of geothermal systems up north in cold climates because 
the cost of supplemental heating in winter outweighs the savings in summer, 
whereas I don't think there's any such thing as a climate that's too hot for 
geothermal to be cost-effective.

Katie
Eastern Village
Silver Spring, MD