Advice needed for Waterfurnace Envision Series Install

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Nov 6, 2022
Mendon, Utah
I built a very nice ICF home with radiant floor heat (Propane boiler heat) and ductwork for a future water to air geothermal system for future heating and cooling. Installed 2 closed loop geothermal systems: one is a large hole excavated 6' deep with 10,000 feet of 3/4" poly pipe in a closed loop "slinky" style covering the bottom of the hole then buried, all connected with a 2" supply and return line to my mechanical room. The second consists of 5,000 feet of 3/4" poly pipe in a closed loop at the bottom of 5 trenches each approximately 120' long and at least 8' deep and 3' wide having 1,000 feet of the "slinky" style 3/4" pipe in the bottom of each trench connected by a 1/14" supply and return line to my mechanical room. I should have enough geothermal heat/cold exchange capacity. They have been pressure tested and are filled with a 40/60 glycol water mixture.

I acquired 2 used geothermal water to air furnaces. Brand: WaterFurnaces, model: Envision, from someone who was just going to trash them because his field system was not large enough to handle the geothermal loads. I assume they still work - just need some basic knowhow on hooking these WaterFurnaces up properly. One is a 6 Ton unit I will connect to my main floor ductwork, the other is a 4 Ton unit I will use for the basement. They will both be in the mechanical room where the supply and return lines are from the 2 field geothermal system. The idea is to get these 2 Waterfurnaces running and use my radiant floor boiler heat as a supplemental heat source as needed.

I can get the piping, circulation pumps and the waterfurnace ductwork setup properly, just need some tech assistance hooking up the 2 Waterfurnaces. Cannot seem to find anyone locally with the knowhow with these systems or even a user's manual online. Looking at the schematics on the furnaces it looks fairly doable, just need some basic guidance. Any help would be appreciated.
I've had a Envision 4 ton unit for the last 12 years. Zero issues except a start capacitor that went bad a few years ago.

I have 2400' ( 4 x 600' ) of either 1.25" or 1" pipe hooked into a 2" manifold. My installer wasn't too fond of slinky loops so mine is in two 300' long trenches. The pipe either goes out at 4' and returns at 6' or goes out at 6' and returns at 4' to the manifold. Two pipes per 3' wide trench. We used methanol instead of glycol, methanol doesn't break down like glycol and is much easier to pump.

I don't know enough to comment about slinky loops after doing some googling. I do know that you aren't going to be able to push a lot of GPM with a 3/4 pipe vs a larger pipe, and you are going to need some serious pumps to do it due to the amount of head.

A simple google search for waterfurnace envision should lead you to their manuals and documentation. Good luck.
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