Forgive me if I missed it, but what was the price for a conventional zoned system? We don't have to pay back 42K, just the price difference.
Joe

That's a very nice observation, Joe, about a way to make the justification easier. (And it makes me I wonder if you have a background in sales. :)

I've not gotten an estimate for a conventional zoned system, but it's been suggested that it would easily be half the geothermal. I have started getting competitive bids for the geothermal.

Thanks!
--David

David, I read you're getting geo bids. Are you confident you're getting accurate Man J & D calculations? If not, I'd recomment you look at www.energywisestructures.com if you're looking for an independent analysis. They're located in McKinney, TX, and are very familiar with homes like the one you will build. We used them recently and will be looking for geo systems later this year. Dave in Kansas

It depends on where any residual air might be trapped.   If the air is located such that it would need to be pushed down the loop before it makes it to the Spiro Vents  ( which we do install on every job ) then it will most likely never get out.

This is why we have invested so much in our purge equipment.  We want to be sure that there is no air in the loop when we leave.

Our pumps are set up to run on 220 volts so our cords don't need to be that big.  We usually hijack th dryer circuit to purge with.

I've read in other threads the desire to have turbulent flow for better heat exchange. If you purge air from the loops, how do you achieve the desired turbulence? Is it a function of velocity, loop diameter, etc.? Or do I need to know as long a loop is designed and installed correctly, including proper purging? Thanks, Dave

 

Dewayne - thanks.  Very interesting.

My guess is you have a checklist of things to make sure are present on a job, and the existence of a 220 V outlet, somewhere is on your list.

Best regards,

Bill

Turbulent flow is a function of velocity.

Velocity is a function of pipe diameter, length,  head pressure, and pump size.

Thank you for that lead, Farmboy.

David,
We live in Bastrop, to the east of Austin. Two weeks ago, we had a geothermal system installed in our approximately 2100 square foot house. Our system includes approximately 1500 feet of horizontal ground loop, a Climate Master Tranquility 27--Earthpure unit (3 ton) with a Carrier ComfortZone IIB modulating damper zone system and three zones. Our desuperheater is not yet connected, and the cost without that was $17,356. The install went like a dream and it's working like a dream, too, but of course we have no idea yet how our energy costs will be impacted. Through our efforts such as radiant barriers, low E windows, LED lights, daylighting and even some cooking on a sun oven, and Bluebonnet Energy's current low costs, our monthly energy bills were already low--about $104, $105, and $150 for the last three months with all our 100+ days in our all-electric home--so our payback may be a while unless Bluebonnet goes up on costs. However, we want costs and usage as low as possible as a prelude perhaps to someday adding a grid-connected PV system, and figure we'll recoup some of our costs because we'll pay less for that system because of the previous efforts we've made. Our installer was Tom Romberg of Action Mechanical Services.

Nice, Linda. And thank you for that reference to Tom Romberg.
--David

Linda,

If at all possible get that desuper connected to a preheat tank soon. With it on my system my total cost for hot water (for a family of 5) since May has been about $15. Desuper has reduced hotwater cost by around 75%. With your closed loop system and likely higher water temps your desuper should work even better than mine.

I have an hourmeter on my 5500 Watt water heater, so I'm quite confident of these values.

Thanks for sharing your system details here

Thanks! The desuperheater was connected earlier this week. We were just waiting for them to schedule the appointment. Everything is still working wonderfully even with all our 100+ temperatures, with the house much more comfortable than it was previously. I'm looking forward to seeing how it helps the electrical usage although we added LED lights in two more rooms this month, too, so it may be difficult to ascertain which savings are linked to what. Since LED lights are so expensive--and we have a daughter who visits often who has seizures and has been advised that CFL's are not right for her by her neurologist--we're doing one room at a time, depending on usage. Kitchen, master bedroom, study, laundry rooms and bathrooms are done, so now we just have guest bedrooms to go.