Hello! I’m not very savvy when it comes to geothermal. We recently purchased a home that was built 1979. Home is located in Iowa and is all electric. We have two separate living quarters, one is main living and the other is a large open pool room. Both areas are well insulated. There are two separate furnaces. We currently have a heat pump, but this winter have used a lot of axilliary heat due to extreme cold. Our highest electric bill this winter was $1000 and the average is $775. Our square footage is around 4800. We received a quote from a company for a Bosch geothermal 10 ton system. We received a quote for $66,670!!! From what I’m reading 10 ton seems very impressive...maybe too impressive and $66,670 seems extreme. We are in the process of receiving another bid and were concerned when wew were told they though they could put in a 6 ton system. That’s quite a difference. Is that usual to put a 10 ton system in a home with 4800 square feet? I have read through some of these forum questions and realize there is a lot more that goes into it but just hoping maybe someone can tell me if it’s completely crazy or maybe legit. Thank in advance!
Your best bet may be to pay someone independent to do a heat loss/heat gain on your home. Then you will have the proper numbers to compare apples to apples.
$60K is not out of range for 10 tons. It depends on the energy usage of your house. How many KWH did you use during your peak month. Analyzing your annual electrical bills should give you a very good idea how much you are using for heating, which can be used to size the system. ost you electrical use here for the year, we can help by having a look at it.
We were charged for close to 8500 kWh our highest month. I think that bill made me so sick I threw it away. The bills I could find are the following..nov/dec-5189Kwh and Feb/March-7357KWH.
Check with your electrical company. We need the accurate numbers for the shoulder season (April/May) or September/October November) which reflect the KWH usage without the heating.
Not totals, how many per month, trying to figure how many were for lights & clothes dryer ect. Those are months when you don't use many KWH's for heat or A/C.
If you lowest in the off season was 5,375 kwh, and the highest was 8,500 KWH assuming that was Jan/Feb, that is only 3,125 KWH for heating. Suggesting the house performs well and a 5 ton system could do the job more than efficient. If I were you I would put in a 5 ton variable speed system, allow its capacity to adapt to any load situations, and move on.
I don't know where in Iowa you are, but I just looked at the weather data from Waterloo Airport, which is the colder part, and they had 1459 heating degree days, with Jan 1st the coldest day with 78.3 heating degrees (autch....). So you end up with 2.15 KWH/HDD, or 168.35 kwh for Jan 1st, which are 574,400 BTUs. Assume that the peak hours are 25% higher than the average of the day, you end up with 30,000 BTU/H design load. This already accounts for the internal gains and the solar gains, but it suggests that a 4 ton heat pump is sufficient. Take those numbers with a grain of salt from someone you don't know from the internet, put in a 5 ton variable speed, and move on. The other issue I would investigate is that you use 5,400-5,500 kwh without heat/month. Something cause a large amount of electricity usage in your home.
We have an indoor pool/spa. The pump is part of the problem. The house also has fluorescent lighting throughout. All these things are in the process of being renovated to be more efficient. Thank you for your suggestions!
I'm not sure why geo costs so much to install. Could it be due to demand? I'm surprised more people don't do it themselves. It's not hard. Ok maybe for the ones that don't want to learn anything.
