Hello Iowa

Insist on a true Manual J.  That will give you an accurate heat load.  In cold climates like yours, the geo guys should be sizing the system on heating, not cooling - cooling requirements are about 2/3 heating.  Divide the heat load by 12,000 - and this will give you accurate tonnage required.  Do not oversize or undersize the system.  This is critical.  Make certain you're planning to air seal and insulated the band joists and basement walls below grade.  Your geo guys SHOULD recommend this.  If not, get a different geo company. 

Use a DX ground tap system - it is the least invasive and best COP and SEER.  Water based closed loop systems are less efficient because of the pumps to drive water for the heat transfer.  They're also prone to failure.  At least that's our experience.  We have over 5000 successful installations and happy clients using DX.

Paul Auerbach
Managing Partner
Total Green LLc

Paul, welcome to the forums. We welcome your input. Sounds like you have some good experience to share.  I am not sure what you  mean by this,  but it is simply not true.  We have been around water source heat pumps for years.  We have seen hundreds of installations.  We have never seen one fail on it's own if it has been designed and  installed  correctly.  Certainly if the product is not installed properly or not used in the manner it was intended, then there can be problems.  The same can be said of DX systems.

This forum is not a place for one guy to bad mouth the competition.  I hope you understand my concerns.

Dewayne Dean

Hi Dewayne,

Sorry you took my comments as critical of water loops.  That was not my intent.  What I said was "that's our experience."  While we service our own installations, we've made several service calls on horizontal loops and have seen failure in the pumps.  That's what I was referring to. 

Each application is different and needs to be professionally installed and tweaked post install.  Our concern is fly-by-night installers giving geo itself a bad name.  One bad installation in an area harms the overall perception of geothermal.  And we all know how good geo really is when done right - regardless of the technology employed.

Paul Auerbach
Total Green LLc 

Paul, thanks for responding.

The above  is so true.

   Best wishes to you.

Beware sizing for heat load.

Oversizing the unit so as to avoid operation of strip heat on coldest days has two downsides:

1) AC will cycle off too quickly before properly dehumidifying the house. I realize Iowas has a cold winter but comfort during high humidity days is an important factor.

2) First cost of larger unit - both the unit and much of its ductwork would be bigger and more expensive, possibly also noisier.

Consider ways to better insulate or tighten envelope to reduce heating load.

I concur with advice to spring for a 2 speed unit.

All the units we priced are three stage heating and two stage cooling. Our biggest worry is that with a 3 ton unit we would spend the majority of the winter in the third stage of heat. We understand that on the very cold days that the third stage runs. The insulation will be R49 attic and R19 side walls (cellulose) with a geo caulking package. The basement will have an R10 blanket on the walls. One heating contractor told us that for the cooling side they slow the first stage fan speed down. This makes the fan run longer and dehumidifies the house. The price between the 3 and 4 ton unit is approximately $1200. Thanks for the insight and opinions.