Geothermal heat pump install with crawlspace encapsulation

[jimpen]

Another possibility is to go with PEX Tubing Radiant Floor Heat System Install Options. That cuts all the noise of forced air heating and you can run the geothermal pipe to the floor heating in the winter and have a cut off in the summer to use for the A/C.

 

[japody]

We're in Southside VA, probably 75 miles north of you as the crow flies. We have a Bosch system. To say that we are very pleased is an understatement. The aux heat has never come on. Our electric bill for a 3300 sq ft all electric house has never been over $125 in the winter with the thermostat set at 73. Summer's bill never over $100 with thermostat set at 73. And the de-superheater is an extra plus. You'll enjoy it!

 

[fishheadbob]

I'd look into foam insulation. It's been my experience that critters can gnaw and burrow their way into just about anything. The salesmen claim they won't bother it but claims and reality may not be the same as reality doesn't get paid on commission.
We had our 7 ton Water Furnace installed in May so no real experience except that we traded a $45 propane for hot water bill into a $30 increase in electric which included some new to us central air. The Buffalo area is somewhere that air conditioning isn't mandatory but it came with the system . I'm getting too old to wrestle with making 20+ cords of wood so the geo system sounded like the ticket for me as opposed to a new oil system ($$$$). I'm keeping my central wood for a backup.

 

[MacLawn]

Wow, what a timely post, Geek and others! My Carrier Puron two stage heat pump is now 11 years old, and I've been researching geothermal many years. Just yesterday, after cutting wood and came inside to rest, I noticed wetness at the edges of our oak hardwood floors about 12' from where the inside heat pump unit is located! I knew right away what it was - condensate was backing up and had been leaking for at least a couple days!! So, my geothermal research has just gone into turbo mode!

A question I haven't been able to find an answer to: with geothermal, I'm thinking Water Furnace, Bosch, would there be this inside the house condensate issue? My house is also crawl space.

Looking forward to your progress Geek!

 

[techman]

would there be this inside the house condensate issue?

There will always be a condensate drain at the air handler or unified geo unit, wherever it is located. When cooling the coil causes moisture to condense from the air, and this needs to be drained. Doen not matter what the technology is.

Paul

 

[MacLawn]

Thanks Paul. That's what I thought. This is about the sixth time we've had this problem! A house we rent just leaked from ceiling in garage two weeks ago, water pouring all over! Our house has had condensate dripping issues five times! Something needs to be done by designers to FIX this kind of poor design! My hardwood floor will probably have to be replaced! Oh me.

 

[doxford jim]

Just a thought , can the condensate drain be rerun in a larger size ? I have had to clear the condensate drain on my Waterfurnace several times. On my unit there is an indicator that shows when the condensate drain is plugged, so any damage caused is minor. Probably a tad cheaper than another complete unit.

 

[MacLawn]

Heheheheheeee, right dox, reckon a bigger pipe wouldn't set me back like a geothermal. But, I just have not had good success with heat pumps after my very first one that lasted from 1980 until 2003! It was lp heat and electric cool, but like others said, wow!, gas has gone sky high! I have no LP now at me house, and glad to be shed of it. The drain pipe under my house is about 12' long and has been bowed down in center since it was installed. I had been meaning to tie it up to a gentle slope since it was first done in '80 - well, I tied it up last night! Funny thing though, it seemed to be draining all along. There was water at my outside drain pipe.

Back to ye olde geothermal - I still want one! Maybe I even need one:confused2:

Oh, and if I do, I'm gonna make installer use about a 12" culvert for condensate drain :raincloud:

 

[dpb800]

I had started and participated in a thread or two here recently about geothermal heat pumps, trying to decide if one is right for me. I've decided to pull the trigger and I'll follow the install on this thread.

Background: I'm replacing a dual-fuel air-source heat pump. The backup furnace is propane. When I built my house propane was $1 a gallon. Now as we all know it's much more, and also much more volatile. Plus, the local market here is quickly evolving into a duopoly as the two big players (Amerigas and Ferrellgas) are systematically buying up all the mom-n-pops. So I just don't think conditions are favorable for propane heating any more. Last January, during the polar vortex, one month of propane cost me $850. And that's at a significant discount because I had signed a contract in the fall and was getting a commercial rate, plus I own my tank so was also getting a favorable rate for that.

My system is also aging and in need of replacement. The refrigerant it uses is being phased out, and the system is in bad shape because it's located in a crawlspace and 15 years of humidity under there plus critters messing with the ducts has taken its toll. To protect against the latter I'm also having my crawlspace encapsulated, which I'll discuss in another post.

I spent some time deciding on a system type. I first got a quote for a solar-assisted air-source heat pump. This is a regular heat pump system plus solar panels through which refrigerant circulates, making the heat pump more efficient. The research I did made me think this was more a gimmick to make a regular heat pump eligible for energy efficiency credits, than a real efficient system. I settled on geothermal because it's by far the most efficient plus I have the land to do a trench system, reducing cost vs wells.

Cost was a factor and here tax credits are a big help. There is a 30% federal tax credit on a geothermal installation. Plus the state of North Carolina has a 35% credit so in the end that works out to over a 50% discount on the system. I say 50% discount, not the 65% discount that would seem apparent because:

• The state tax reduction also reduces your state income tax deduction on your federal taxes, so for all practical purposes you pay federal income tax on the state tax credit
• The NC credit is capped at $10,500

I did a lot of doodling around in this spreadsheet: http://www.eia.gov/tools/faqs/heatcalc.xls. Putting in local values and playing around, plus the fact that I have the land to do it, a geothermal system looked like a no-brainer.

I'll be putting in a 5 ton ClimateMaster Tranquility with gas backup. It may sound funny to say I'm getting the gas backup after what I said above, but all research I've done shows that geothermal systems around here almost never need backup heat. The gas backup is just for peace of mind because I can run it off my 5500W generator in the event of an extended power outage (which ice storms out here can cause), or if a problem develops with the geothermal system. The gas backup will be manually controlled, not on a thermostat, so I can turn it on and off as I want. I expect to run it very seldom, but who knows, if the price of propane crashes, I could run it more. I will have 7 trenches, 150 feet each.

The trenches will be in my pasture. While the trenches are being installed and the grass regrown, the horse will be living in the training round pen and her stall. It's an inconvenience but she's old and doesn't need a lot of running room any more so she'll be fine.

Once this project starts my pasture will be completely torn up. So I've attached a picture of what it looks like now, because it won't look this good again for a long time! The pasture also has a french drain through it that will need to be avoided by the trenches, it's marked with the orange spray paint. Finally, the horse in her temporary lodging.

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This sounds just like our situation a few years ago. We purchased a home and replaced the propane furnace with Geothermal and a propane backup furnace. We were able to take advantage of Federal and State rebates that provided a significant savings. We wanted the propane backup due to the possibility of extended periods of power outages after harsh winter storms. The propane backup furnace would require little power to run from a generator and would keep the house nice and warm.

We ended up with a Bosch 3 ton unit with three 300ft horizontal runs. The cost savings over propane was enormous. Went from an average of $300 per month (averaged over 12 months) for propane costs to an additional $50 to $75 per month on the electric bill to run the Geo. It helps that we also get to use a lower priced electric meter for the Geo system. Electric rate is nearly half that of normal electric. The Geo does an amazing job of keeping the house at 70 all year long. It is quiet and does not have any of the hot or cold spots throughout the house as with a traditional system. We have not needed to run the backup propane heater nor has the geo not been able to keep up with any of the cold windy winter nights. We even had a -25F night that it had no problem with.

By the way, our horizontal feild was installed using a boring machine. This leaves a very small part of the yard disturbed and only takes a day to install the feild. The boring machine was also capable of running the feild at a depth of 15 feet which would be cost prohibitive if you were trenching yet provides a more stable ground temprature deeper down. Very slick way to run the feilds and costs less than wells too. You could consider this option and not have to move the horse or worry about the french drain.

 

[Country Geek]

That's cool about the boring. Not sure why no one seems to offer it as an option here except that our soil can be rocky and have voids, etc... maybe they need to dig a trench to see what their getting and/or remove rock and other obstructions?