My Barndominium is 3000 SF with 15’ ceilings. Inside I have carved out 400SF as a two story apartment. I’ve already run 1/2” pex in the floor and am ready to buy the rest of the system.
Propane was the initial plan, but the prices are outrageous. Can anyone help me design a geothermal system that I can heat DHW, heat a closed floor loop for my radiant system AND provide AC just on the apartment side? Oh, and I’m on well water.
It CAN BE DONE, but you are NOT going to get the design service for free ! On top of that, the installation costs will be VERY HIGH !
Geothermal heat pumps are very cost effective to run, so you will recover your money. The combination of in floor heat and A/C adds another complication. It can be done, just more installation costs.
My only advice is install wells, not horizontal tubes. With wells you can add more if required.
Wiz the only cost difference will be the heat source in this simple system. How much is a Propane Boiler vs a Geo Heat Pump and Wells? Yes there will be more cost but what is the ROI. A basic simple calculation will tell the OP which direction to go.
Adding AC does not complicate the system. It is just another source of heat and cooling with a cost difference. No more complication.
I have both Wells and Loop Field. Using directional boring you can add to a Loop Field same as a well field and the cost in our area is about the same when we did ours.
I'd be nervous about geothermal. When they don't work well, it's an expensive problem.
How about an air source heat pump with propane backup?
They don't work well because they are not designed properly. You need to find a contractor that knows what they are doing and have experience and training in Geothermal. It is 100% science. I called 8 of our Geo designers customers and they were all happy. No complaints.
All the stuff you read on the web is the ****** negative stuff. Heck I did a write up on here about how our Gas Back-up Boiler blew up. Negative. I have never done a write up about how well our Garage Door Open on the third stall performs.
We have 2 Geo System. One for the house and one for the Shop. The house has wells and the shop ground loops.
The house system is design to run down to -7° without assistance. From -8° to -1 million° there is a Natural Gas Boiler with heating coils in each of the forced air furnace/heat pumps. There is also a heat pump for the in-floor systems which also can be supplemented by the backup boiler. The Backup boiler is the main source for heating the water.
So there are 3 forced air furnace/heat pumps/AC, one for the main floor, one for the second floor, one for the bonus room above the garage in-floor heat pump (11 Zones: Anything concrete or tile has in-floor including the whole basement and upper and lower garages). Since no HVAC Contractor I have found yet can balance a house anymore I made them do the upstairs, downstairs and bonus room on 3 separate systems. The House system has 20 140 Foot vertical loops. Originally we were going to have (16) 180 foot loops but we hit fractured bedrock at 140. So we added 4 more loops to get the capacity we need. These are all water to water exchange.
Cost was about 33%+/- over conventional. At the time there was a tax rebate of 30%. Based on having a dual heat system. Geo with a natural gas back-up the house qualified for the POCO's "Back-up Relief Program". Thus any kilowatt hours the Geo systems uses is at a 50% discount.
According to the "study" based on the house and the system design Geo can save you tons of money with an initial higher investment up front. Based on 2008 (when we built) electric rates the savings over a 20 year period was estimated at $110,000.00 or $458 per month. The ROI was 4.6 years (I think, Memory again, and time the Government was offering a 30% tax credit to and that is considered in the ROI.)
Maintenance? There really isn't any other than changing filters and looking for leaks. When it gets below zero I look the system over morning and evening to make sure everything is cycling as it should.
Problems? On the house system really nothing. In the beginning the in-floor boiler would trip out showing a high pressure issue. After some head scratching and chin rubbing the tech and I sorted out that the gas boiler supplemental heat load out was routed to the heat pump load out thus the lines were reversed creating the issue. That was an installation issue...rather complex system.
Next problem. Our Triangle Tube Boiler blew up. That had nothing to do with the system.
The shop: 2 heat pumps for the in-floor and one forced air furnace/heat pump/AC. 7 Zones.
On the shop we tried the Vertical loops but hit fractured bedrock at 70 feet only 800 feet SSE of the house loop field. We ended up going with (8) 300 foot directional bored horizontal loops. This is just as effective in my area based on a high water table. We bored at and average depth of 20 feet and were in water the whole time. Water has the best thermal transfer. If you run a horizontal loop in dry sand or clay you will have problems with thermal transfer.
"A properly design system will pay for itself. My shop is 10574 sq feet. I heat office and vault, 832 sq ft feet to 68°, the car shop, machine shop, storage room, and utility room totaling 4320 sq ft to 62° and the 5422 sq ft "Cold Storage" to 50° and the highest bill this year so far with how cold it got this year was $216. Last year the highest bill was $162 with a mild winter. Air Conditioning everything except the "Cold Storage" Area is more than effective. Averaging $37.00 per month in the peak of the heat. All these costs leave out the meter rental and service charges." (quoted from another misleading GJ Thread).
OP do your research. Filter it and use caution when you seek advise or opinion on the GJ (or any web-site)...those who post a solution or opinion on every thread or most of them cannot be experts in all those fields.
Above is my shared experience with Geo...I am interested in which direction you go.
