Literature on Geothermal

Check with IGSHPA…I took some classes with them in the fall of 2024

https://igshpa.org/

If you are looking for information on cost savings of a geothermal vs a standard forced air system, let me tell you about 2 neighbors of mine. They both replaced the geothermal systems that were 20 years old with a Lennox high efficiency gas furnace and a high efficiency A/C system. They are both very pleased with the results. They claim to be saving money on the cost of operation, both summer and winter, and have less service costs. Their geothermal systems consisted of coils of black plastic pipe buried 6' underground. I have no specifications on the geothermal systems installation. They are located in south western Pa.

Fracking really killed the cost benefit of ground source heating. I think a vertical well with closed loop would be much better than coils at 6' but still I couldn't show an operating cost difference between mine and natural gas forced air.

Of course I got very efficient summer cooling also for no additional up-front cost, and I loved how nice the heat pump was.

What type of soil are the pipe runs buried in?

Do the 7 loops of pipe consist of individual 500 foot long rolls/reels of High Density Polyethylene pipe with no butt fused pipe connections except at the header pipes?

What is the depth that the tubing loops are buried in?

Were the loops buried below the frost line if that applies here?

What is the separation distance between in feet between each pipe run?

What machinery is/was used to excavate the trenches?

Was the pipe pushed to one side edge of the trench and dirt piled on it every 10 or 20 feet to hold the HDPE in place prior to thier burial?

Was the rock in the trench dirt separated from the soil before the burial of the pipe?

I wish those were deeper

We are good here Paul. It is a world of difference compared to NJ or even east of the Cascades in Washington. It gets wicked cold there.

Take a look at the design standards and Manual J information. It is just mild. I have never observed over 100 or below 23 myself.

We could get by with good shades and fans and no AC but we are wimps.

I did my own Manual J with Lennox Design pros Cool Calc.

I came up with 25018 BTUH heating and 21002 cooling, and a little less than 1000 CFM

Then I paid an engineer to go through it with me, do his own Manual J and design a system for me.

He came up with 31091 heating and 27443 cooling and ~1100 CFM, a little more conservative.

I had already set my sights on a Bosch 3 ton unit with an air handler for cooling.

I went with a 4 ton inverter that should be loafing, and gave it almost 6 ton equivalent of loops.

That said, I am going to call them and opt for a 6 ton AHU that includes 2x5KW strip heaters and about double the coil capacity. I think it will be a better match for my planned 105 SWT on design heat day and I can kick in the strips to take the edge off quickly if ever needed.

The 3 ton Bosch became unavailable, unfortunately. It was not a DC inverter unit like the 4 ton, and therefore was not a good match with my11.4Kw inverter. It had big Locked Rotor Amps (LRA), where this 4 ton is quite gentle on the uptake.

I had not planned on having the heat pump on the critical loads panel but now I can. The heat will work, the lights, and the fridge during a power outage. That covers all the main bases.

It is all down 6' +. I moved 300 tons of clay several times back and forth in different motions, the goal being to not disturb all the grass up there.

Here you can see the loops as they arrive at the house, 6' + down. If they are located down the hill, they are dug down an appropriate amount. It is just hard to visualize it so I marked the corners of the loops with 8' boards. That big ridge on the right is just stored there to backfill the house when I can. The flattish surface is the first time I could visualize grade.

I need to add some retaining walls and more dirt on the loop to the right. That was the hardest digging on the site there.

The back yard will never be flat. It will get stepped retaining walls to make a flat-ish spot with what I have.

It's come a long way since the rough Ex in September.

looking to stay 40+ deep into the season by alternating loops.