WaterFurnace Proposal Descrepancy

Insulation

This also points to the economic fact that your money is always better spent on insulation than the heating system. It has the best payback. So if you can see a way to reduce your infiltration rates and insulate the walls, you will save yourself that much money right at the start with a smaller design requirement.

 

You might have already said in a previous post, if you will post for me your location ( city and state ) the design temp you want , the BTU load on your house that you feel comfortable with, and the soil / rock type in your area, I will run a loop design for you.

 

Thanks for the offer

Palacegeo,
Thanks but I am comfortable with loop criteria given to me and I do not want to burden you. Both companies offer 10 year warranties on entire system and one offers 55 year warranty on loop field (sounds like an important consideration). I have list of references and will do a bit of due dilligence and make decision. I have decided to go with load calcs assuming exterior wall insulation. It will force me to properly insulate my home.
thanks again, Dave

 

Reply for proper design

Dave, I sent you a message in response to your concerns. Based on what I have read , your contractor in my opinion , MUST be accredited by the International Geothermal Heat Pump Assoc.

 

Long run times in 2nd stage perfectly OK on long winter nights.

I checked Harrisburg, Hagerstown, and York in my design software and winter design temp is 11-12 degrees.

I share Palacegeo's skepticism concerning a minimum Entering water temp of 40 deg F. 30 sounds much more likely. By the way the 80 maximum refers to summer cooling.

Deep ground temperature in your area is likely 55 or so, though I can't find my map of that right now.

To learn more about individual unit's capacity at various entering water temps download Waterfurnace pdf of Envision specifications - tables therein detail capacities for every 10 degrees of loop water temp.

 

IGSHPA accreditation is a good place to start, but should not be the deciding factor.

I have been to IGSPHA training, it is very basic with no hands on training in design or install. In fact they stress that it is not a design course.

The best way to choose a designer / installer is to get references and call them. If they don't have a great track record of happy customers over several years, then you are taking your chances.

I realize that not every one has the option of choosing from well qualified contractors. If you can't find one, then make sure to protect yourself by getting a performance guarantee in writing. Don't pay them in full until you know that the system is performing up to standards.

 

York college

The college in York PA got a lot of press 2years? ago. It is a closed loop design and I think they used 300 foot bores, do not remember the diameter. If you can find out the engineering firm responsible, you will find that they did an actual conductivity test for the project. You may be able to cross over their data.

In regard to a 55 year garrauntee on the loop field, buyer beware, they are promising that the pipe will not fail, not that the field will operate properly.

Eric

 

Consider your current utility-bill..

The best way to decide heating and cooling size determination would be your current heating bill. Using higest heating bill of the month, calculate total energy need (gas or oil volume consummed) for the heating. in terms of calorie or BTU. Then you can easily decide the size of your heat-pump.

Good Luck on Your Geothermal Heat Pump System.

I would go with 5 ton system with supplimental heat or higher. Supplimental heat source does not cost much and will guarantee your heating needs in extreme condition.

SaeHeum Song,
www.noblegeofurnace.com