Holy Power Costs, batman!

beelzerob said:
We have a generator subpanel and portable generator, but the heat isn't wired into it. That's what the fireplace is for, mainly. It adds heat during the colder days of winter, but it was mostly thought of as our most emergency-type heat.

I have an air to air exchanger, I guess you'd call it. There's the big unit outside that gets the heat from the air, and then it brings it into the inside unit where the fan is.

Not varying during winter is part of the reason I'd like geothermal, because like I said...when it's down in the single digits downstairs, I see upper 70's for duct temps, but when it's in the 40's, it's closer to 100.

If the geothermal is always exchanging with water that's around ground temperature (around 50 deg or so) then I guess I don't understand why it'd have to run all the time, or wouldn't even be able to keep the house warm. Isn't that more than enough heat coming out? If my air exchange heat pump can produce 100 deg of heat from 40 deg air, I'd think a ground exchange would do even better with 50 deg water.
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Depending on if you have a horizontal ground loop or open loop system, it's a misconception that the ground can replenish the heat as quickly as you can pull it out.
When it was real cold last month, I put a thermocouple into the supply loop to see what the delta T was running, and even though our ground temps here run about 50F at 6' depth, my water supply temps were about 34F or so.
That's typical for end of season in my opinion. My feeling is that you probably lose a bit of capacity as the winter goes on. I'll work on improving the tightness of my house over this year and hopefully keep up a bit better next year.
Meanwhile, I'm using propane to supplement.
 
Ya, I knew that the water in the loop would get "colder" over the winter, as the heat doesn't flow that fast through the ground to the loops. Low 30's doesn't seem so bad, I was hearing that temps get into the single digits towards end of winter in horizontal loop systems here.

Is yours horizontal or vertical loops? I'd think vertical would be better at replenishing the heat, wouldn't it?

I think we're still a couple years out from being able to seriously consider geothermal...at least in that time, I should be able to log and note my heating/cooling costs separately, so that will give me some better idea of the payoff time.
 
DavidL said:
In the transfer switch, there is a 100amp double pole breaker that backfeeds another pair of breakers in the main power panel. I can manually turn off the utility mains on all panels (completely independent of a backfeed situation), and then turn on both double pole breakers.
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Thanks for the info David.

I have the same switch you have, my electrician also installed a set of 100 amp breakers in the transfer switch and fed that to a standard 200 amp service panel to overcome the 16 breaker limit.

I like the way they did yours, but I have a 600 amp service with several 200 amp breaker panels spread throughout the house and garage, I don't think it would work as well for my setup.

Brian
 
"I like the way they did yours, but I have a 600 amp service with several 200 amp breaker panels spread throughout the house and garage, I don't think it would work as well for my setup.

Brian"

How is your 600amp service split up? Is there one 600 amp breaker? (doubtful). I assume that there is a 600 amp breaker bar (fed by the utility meter), with your multiple 200amp service panels coming off of that? Is one or more of the service panels then getting further distributed to subpanels in those "remote" locations?

I have a 200amp main panel, and a 200amp "cheap energy" panel (HVAC and water heat) and a 300 amp seperate, commercial service, panel for my barn. The "main" panel is then split to multiple subpanels located around the house and to the boat house (small seperate building).
 
Back to Geo...
Installed the new Water to Air Geo unit (6ton) yesterday and all is working again nicely. Cleaned up a lot of the utility room while I was at it. The emergency propane furnace goes in sometime this week. Need to do some duct fabrication to tie it all together.

I installed several water temp test ports for monitoring.

My last geo used a freon pressure regulated water flow valve that changed flow rate dependent on freon pressure that is temperature linked. Nice in theory, but I have had reliability problems with the valve in the past. The new one uses an electric solenoid and a fixed flow rate water regulator. The regulator does dynamically compensate for differences in water pressure. Looks like it likes 10gpm. The temp test ports come in to tune the system to minimize water but provide enough water to not freeze the system. They are also there to tell the HA system that there is a problem. The geo controller also monitors temp and will shutdown the system if getting too close to freeze (not enough water).

At least the house is warm again :)

There are now two stages of electric (toaster) coils. The secondary heat is triggered by the RCS-TR40 thermostat, and kicking in Stage 2 and Stage 3 of the electric coils is regulated by the geo main controller board.

Initial measurement is 23amps / 220v for the geo compressor while running. I ran a 8Gauge 50 amp breaker for this.

The 2nd stage toaster is run on it's own 6Gauge 50 amp breaker.
The 3rd stage toaster is run on it's own 10Gauge 20amp breaker.
 
beelzerob said:
Ya, I knew that the water in the loop would get "colder" over the winter, as the heat doesn't flow that fast through the ground to the loops. Low 30's doesn't seem so bad, I was hearing that temps get into the single digits towards end of winter in horizontal loop systems here.

Is yours horizontal or vertical loops? I'd think vertical would be better at replenishing the heat, wouldn't it?

I think we're still a couple years out from being able to seriously consider geothermal...at least in that time, I should be able to log and note my heating/cooling costs separately, so that will give me some better idea of the payoff time.
Click to expand...

My loop is a 4 ton horizontal, which is made of 1.25" black polyethelene piping. 4 loops 600' long at 6' deep.

Vertical is better for heat transfer, however, drilling costs $$$$. Horizontal is cheaper. I've got the acreage too.
 
Ya, I really don't have the space. Plus I figure if I'm going to do this, I should just plan to afford the best system. I know I'd get better heat transfer from an open loop water system, but I don't want to dual-use my water well, so that's another water well, a waste well, and another pump. Yikes!
 
Getting back to HA electronics, I suggested to an engineer who was building a net-zero house here about automation.

http://www.riverdalenetzero.ca/Home.html

He took one look at the cost of operation and said it wouldn't work. As mentioned, the cost of running the HA computer was excessive for the concept, but he also pointed out that the "smart" switches used power- approx 4 watts. If you have 30 or 40 of those, it adds up fast.

Are there any switches or other automation devices out there that have less consumption?

bob
 
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