Hello, I am new member to this forum. I am looking to go Geothermal heating and cooling for my home. My house is around 3800sqft with 2 zone heating (propane furnace) and cooling(AC) system. One of my biggest issues is the propane heating bills. This has been a pain since I brought the house with around $5k / year in heating and cooling costs ( this is after deducting what my Solar Panels produce ) My downstairs AC stopped working so started researching options and came across the Air based heat pumps which reverse for cooling and heating. On further research I came to know they are not good for below 40F temperatures. Then I stumbled across this forum which has so much useful information. I had a manual J done by a HVAC guy for an air based heat pump + propane furnace. He suggested I need a 4 ton for 1st floor and 3.5 ton for 2nd floor for the air-heat pump. For the furnace he suggested 90K BTU for 1st floor and 75K BTU for 2nd floor. The approx cost for a top of line Air Heat pump + Furnace hybrid system came to approx $30-35K. When I was researching it looked like a similar sized unit ( 7 ton WF 7 ) Geothermal install would be possible in the $40K-$60K price range before rebates. I recently called a vendor for a Geo unit estimate and he said for a Water Furnace 7 series 7 ton unit it could cost about $97K before tax rebate. I literally fell off the chair. Hence I am seeking some guidance on what you think it should cost for a Water Furnace 7 series GEO unit ( 2 zone for 1st and 2nd floor - totaling 7-8ton )? Also any suggestions on good contractors in the Hunterdon County ( i am in Flemington NJ )?
WaterFurnace Series7 come in 3, 4, and 5 ton nominal capacities. No 7 ton. So you are talking 2 units to make up 7 tons. This would nearly double the cost of your typical one unit system. You can not size geo units based on air source HP capacities. ASHP capacities drop significantly more than a GSHP would under extreme design conditions. You will need to know the actual ManualJ BTU loads of your house and compare to published capacity tables under your particular design conditions for selected equipment.
Thank you for your response. Would you have some information on the Geo capacity tables so I can determine what size i may need. The dilemma I have is should I go with a Air-heat pump + Propane furnace hybrid which also should save my bills by about 40-50%. Even that would take me 10 years to break-even. If I go GEO no way I can recoupe the costs any time soon. What do others who have similar sqft (3500sqft) do in terms of Geo? I was told the drilling costs account to about 35%, so is the equipment that expensive... Based on facts I am thinking of dropping the idea of Geo but sad as I was very excited with all the research & positive reviews of Geo.
I have a problem with my ROI calc. My furnace and AC are about 15 years old and one of the AC broke so I think there is still life left in my furnace units ( it turns out the 1st floor furnace is actually a high efficiency unit ). So thinking do I really need to replace all of it or just install a heat pump in 1st floor and see how it goes? In other words my options are Current Energy costs/year = $5k Option A: Install heat pump in 1st floor couple with existing furnace as backup for <30F temperature ( leave all other equipment intact ). My biggest heating expense comes from 1st flr furnace which should drop heating costs by 20-30% - ROI = 10years ( Initial Cost $10K to install 1 Heat Pump 4ton) Risk: Other equipment could fail in next 5-10 years Option B: Replace all equipment with Air-Heat Pump + Propane furnace hybrid. Cost saves expected 40-50% ROI = 15 years (Initial Cost $30-35K for 7.5ton) Risk: Initial investment and delayed ROI Option C: Go for a 7ton Geo WF7 . Cost saves expected 60-70%? ROI = 20years ( Initial Cost 97K post rebate = 70k) Risk: High initial cost and delayed ROI Any thoughts on my ROI calc above? Geo looks good but for me the break even seems very high but need to think it through I guess.
Not true, there are units that can provide 80% of capacity at -5F. On Green Building Adviser there is a blog about mini-split heat pumps, ductless and ducted. https://www.greenbuildingadvisor.com/article/getting-the-right-minisplit. You might have to sign up for a trial Prime membership. Dana Dorsett is a participant that is very knowledgeable about mini-splits. Chris
