New member here and am looking for advice from experienced others. I hope to install vertical heat pump wells late spring. They (2) will be drilled 400 feet, 20 feet apart. The ground temperature here in Massachusetts is a constant 50 degrees F at depths greater than 20 feet. A well drill told me these wells should support 5 ton system. I just finished an energy loss analysis of my home done for the worst case in both insulation and delta T (75). My analysis has my heat loss at 29412 BTU with weather temperature at 0 degrees, inside at 75 degrees. Gees, I hate to just have a 2.5 ton system installed. What I prefer is to go with 2 each 2 ton systems that have varying pump speeds. Suggestions??? Question 2. A local driller told me his price to drill those 2 400 feet holes and install the needed pipes in each and bring those pipes to the house is about $29K. Is that reasonable? Now to make things more interesting, others I have talked with project the total cost to be around $100K!! I just cannot see why. The wells are the big swallow while the pumps are about 5K or so each. So should an installation cost $60K???? That is ridiculous! Foggysail

Ground source heat pump systems have always been ridiculous and a scam of sorts. People just look at the great COP when this excessively complicated system operates the way it should...which isn't often the reality...and they don't bother to do a Return on Investment analysis because if they did it they would quickly learn that one doesn’t exist... I tend to think of these systems as best suited for people with more money than brains.

Now, if you had real Geothermal like what comes from Old Faithful in Yellowstone, that would be worth pursuing.

If you over design both the heat pump capacity and the loop field, you shouldn't be surprised to see a high cost.

If the heat load is 2.5 tons, why not go with a single 3 ton heat pump ? With a single well bore ? If temperatures go below zero, maybe you cant get the house to 75 degrees for a day or two until it warms up. Is that a disaster ? Sweaters and long johns work too. Dual heat pumps adds complexity (and cost). What do you mean when you say heat pumps with varying pump speed and what is the application / benefit ?

Keep it simple.

Much of the cost will be in the distribution network. Will this be forced air ? In floor heating ?

I personally dont see water to water heat pumps as being all that complex once the system is broken down into its functional components.