My apartment building is partially served by a ground source heat pump that has been set up to pull water out of one well, and dump it into another. The problem is this setup causes the submersible pump to break down often, thus cutting off the water supply to all the tennants, until the pump is fixed.

I want to switch it to a closed loop system, and want to know how much Poly pipe I need to bury and how long of a trench I need to dig, with a backhoe of course, to set this up. I'd also like to know if I need an extra circulator pump to move the water through the loop.

Any help would be much appreciated.

Ferghus.

You need a design engineer that has a business doing ground source work not a help board for broken furnaces. I do not believe anyone here does design work.

WaterFurnace : Geothermal Energy Systems for Home Heating, Cooling, and Air Conditioning.

IGSHPA - Down to Earth Energy

EERE Consumer's Guide: Selecting and Installing a Geothermal Heat Pump System


Google is full of ideas but first you will have to have a survey of the location you plan to use to determine if it can be used for your system. One step at a time.

Design Engineer... righttttttt. Not. Thanks for the links though.

I've already stubbed out the connections for the new horizontal closed loop. I'll be using 1 1/4 inch black poly pipe... the medium thickness stuff. I have over two acres area to dig the trench, and I'm borrowing a backhoe from a friend, and yes, I've been a remodeling contractor for years and have driven a backhoe. I also know the HeatPump is a 4 ton unit.

My question is, how long do I need to dig the trench and how much poly pipe do I need to lay? 1000 feet?

I live near Chicago, IL and our frost line is 2 - 3 feet deep. Actually, it rarely gets below 1 foot... but it has happened.

My question is, how long do I need to dig the trench and how much poly pipe do I need to lay? 1000 feet?

That is where the design engineer comes to play. Now you can be your own design engineer but I will warn you the calculations have to be EXACT. That is why I provided you with starter links so you could do your own research and find all the info you need. This is somewhat of a exacting science so if a failure does happen at least you will only have yourself to blame.

I always used a design engineer for my underground calculations. The logic was simple. When the design is wrong and does not work the engineers insurance paid me to do corrections. When you are doing HVAC work for a living and you have employees that depend upon you for there paycheck you cannot afford to have a 20,000.00 mistake that my company would have to pay for.

The engineers fees were just rolled into the estimate so we made the same amount of profit without the risk. Since you are doing all this yourself that is also great but you will also have to accept all the risk and do your own calculations. If mistakes are made you get to eat them. Good luck on your project.

BTW sometimes a soils engineers report is also helpful to gauge the maximum possible BTU soil transfer rate at different depths or loctions on your land but here again a man of your experience can probably just look at the soil and tell what that could be. Same goes for compaction on the back fill.