Great forum, excellent source of information. I have two quotes to install Geothermal in my house: House is 3500 sqft, two story detached house with walkout finished basement facing north. The rest of the basement is mostly below ground level. House is 12 years old and is well insulated and located in southwest Ohio. Currently heated with natural gas and AC is a 3 ton seer 8. The blower is single speed. In the summer, the upstairs are much hotter than the first floor. Both quotes are based on quite different load calculations, so I'd like to check if either one of these calculations is unrealistic. Otherwise, looks like Quote 2 is a no-brainer. Quote 1: ClimateMaster Tranquility 20 EarthPure Single Stage Capacity: 5 Ton Heating Load: 107,000 Cooling Load : 54,000 Cooling Load Temp Diff: 25F % of heating load: 89% Auxiliary Heat: Natural Gas Furnace (cost of $191 p.a.) Cooling Efficiency: 15.4 eer and 4,565 kWh (annual cost of $700) Loop: Avg 100 Feet Length 900 Feet grouted. Total estimated annual cost: $2000 Installation Cost: 29K (I asked them to quote a 4 Ton instead of 5 Ton and that changed the cost to 25.5K, but heating load went down to 83%, still with natural gas furnace) Quote 2: WaterFurnace 5 Series Dual Capacity Capacity: 4 Ton Heating Load: 58,000 Cooling Load : 30,000 Cooling Load Temp Diff: 17F % of heating load: 99% Auxiliary Heat: Electric 10KW (cost of $14 p.a.) Cooling Efficiency: 18.08 eer and 1,500 kWh (annual cost of $231) Loop: Avg 75 Feet Length 600 Ft grouted. Total estimated annual cost: $1400 Installation cost: 24K
Mark: Close to Cincinnati, different drillers. When you consider the loads, are you looking at the loads determined by Quote 1 or Quote 2?
A relatively new 3,500 sqf house in Ohio should not have a a 107KBTU/h heat loss, nor should it have a cooling load of 54KBTU/h. Half of that is more realistic, what quote 2 reflects. In addition, a single stage unit (quote 1) is cutting a corner at this price level, the 5 series waterfurnace (quote 2) is a higher end 2-stage, more efficient unit, which will provide greater comfort.
I don't like the load for number one or the design percent of heating. We do tend to use larger systems if we are using gas back up but the numbers seem imaginary. That said, you need more opinions. Don't worry about heat pump brand, worry about installer.
My daughter is near you. I, too think you should keep looking. I might buy a DIY heat loss. If you are going to spend that much money I would have zoned the duct work up and down. Mark
I'm looking at a 4 Ton WF Series 5 as a replacement for an existing 21 year old WF two speed. So I'm reusing the existing loop, mine is vertical (500' via two 250' vertical loops). I'm also reusing my loop pumping. My price is coming in at about $14K and includes the DeSuperHeater (DSH) hot water tap. I think that adds over $1,000 to cost, not sure. In any case your 4Ton price is just over mine by about $10K can you associate that with the cost of the loop/pumping station? If so, and you are also getting the DSH (suppose not with natural gas I bet gas hot water is already low cost hot water), oh yes, my price includes aux/emergency electric resistive heat at about $500 additional I think. You have natural gas back up emergency heat. Well, to the heat loss, my 30 year old 2,000 square foot two story house has an estimated heat loss/load of about 45KBTU and the 4 Ton unit has a cross-over with loss at zero degrees - so no secondary heat is expected to be needed. I'd not go for a single speed HP, my existing two speed compressor is still running so the extra wear of switching speeds has not caused an early failure of the compressor. I am also considering the next lower unit a 3 or 3.5 Ton, not sure how these units are rated, It think on the BTU cooling capacity which is always higher than the heating capacity.
