Tag Archives: Pole barn geothermal

Geothermal Heating/Cooling

Geothermal Heating/Cooling for Post Frame Buildings

I’ve opined upon geothermal heating and cooling for post frame buildings in the past (https://www.hansenpolebuildings.com/2016/12/modern-post-frame-buildings-geothermal/). Reader STEVE in BOYNE CITY had some further questions and writes:

“You said you pump (approx.) 55 degree liquid through pex in ”wells” in the ground (I think is how you put it) through your concrete floor to maintain the slab at that temp. Then you heat the air space above the slab to whatever you want ambient to be. When you said wells did you really mean troughs? More importantly, in hot humid weather, is there a condensation problem on the slab and if so, are ceiling fans used? If the slab is covered with a thin, moderately conductive thermal break like vinyl flooring, how would that affect the temperature moderating effects of the slab? Condensation? Is air conditioning ever needed? PS. I had the idea to do this years ago, and all the older guys in the trades said it was a stupid idea. I am glad you proved it to be a worthy idea.”

When I remodeled what was then my grandparent’s lake cabin outside of Spokane, WA in 1990, I tried to convince my HVAC guy using geothermal wells would be a good idea. Sadly, I let him talk me out of it as I am now (hindsight giving us all 20/20 vision) fully convinced the investment into drilling the wells would have been recouped many times over.

Outdoor temperatures fluctuate with the changing seasons but underground temperatures don’t change as dramatically, thanks to the insulating properties of the earth. Four to six feet below ground (below the frost line), temperatures remain relatively constant year-round. A geothermal system, which typically consists of an indoor handling unit and a buried system of pipes, called an earth loop, and/or a pump to reinjection well, capitalizes on these constant temperatures to provide “free” energy.

Gambrel roof pole barnThe pipes which make up an earth loop are usually made of polyethylene (PEX) and can be buried under the ground horizontally or vertically, depending on the characteristics of the site. In the case of our 2004 pole building in SD,  the loops are buried vertically, hence wells.

In winter, fluid circulating through the system’s earth loop or well absorbs stored heat from the ground and carries it indoors. The indoor unit compresses the heat to a higher temperature and distributes it throughout the building, as if it were an air conditioner running in reverse. In summer, the geothermal HVAC system pulls heat from the building and carries it through the earth loop/pump to reinjection well, where it deposits the heat into the cooler earth/aquifer.

The airspace above the slab is heated by the compressed heated liquid running through the pex tubes, although in spaces designed to be offices, the bathroom and kitchenette, they are heated by forced air (where heating/cooling is also generated by the same process as heating/cooling for the slab). We live where it can be 100 degrees and 100% humidity in August and have never experienced condensation on the slab. This could be due, in part, to having a well sealed vapor barrier underneath the concrete slab.

Stone, tile, wood and vinyl are fairly good conductors of heat and do not present any special design considerations. Carpeting may require more temperature from below to allow the heat through.

For more answers on radiant in floor heat, we recommend contacting Les Graham at Radiant Outfitters www.radiantoutfitters.com.

 

 

Modern Post Frame Buildings and Geothermal

Modern Post Frame Buildings and Geothermal

Over the past few years, there has been a trend towards building modern climate controlled post frame buildings for homes and commercial use, but the HVAC Systems in these buildings remains outdated. Most climate controlled post frame buildings are still being built with inefficient gas or propane furnaces, coupled sometimes with an air source air conditioning unit. Some post frame buildings are being built with ductless heating and cooling systems coupled with electric resistance heaters, but this is just as ineffective and environmentally harmful as natural gas. A geothermal heating and cooling system is the ideal HVAC system for a modern climate controlled post frame building. It is efficient, economic, environmentally friendly, safe, comfortable, flexible, and is overall the perfect HVAC system.

Gambrel roof pole barnThe cost of building ownership is comprised of its principal, interest, tax, insurance, energy, utility and maintenance costs. While geothermal will increase the principal payment of your post frame building, it will cut the energy costs by 50% – 70% for the lifetime of the building. At the end of the day, the cost of building ownership is actually LESS with geothermal than with a conventional HVAC system . Geothermal, in comparison to conventional HVAC, is cleaner, greener, more efficient, safer, lasts longer, more elegant, has lower maintenance costs, is flexible to design & install, is more comfortable, and reduces your post frame building’s carbon footprint by more than half!  

Geothermal allows for a huge flexibility in the selection of a delivery system. You can have virtually any heating and cooling delivery system you want! Geothermal is a 3-in-1 System. It will heat in the winter, cool in the summer, and heat your domestic hot water year round!

Regardless of which side of the fence you stand on the heavily debated climate change issue continuing to burn gas, oil, or propane to heat a building makes NO SENSE when you can heat your post frame with geothermal without lighting a single flame!

If you are a person who wants to Reduce Your Carbon Footprint, then a Geothermal System also becomes the obvious choice. Natural gas and ductless plus electric resistance systems emit about three to four times more CO2 than a geothermal system.  Propane and oil systems are even worse, emitting 35-40 TIMES MORE CO2 than a Geothermal System!

As quoted from the U.S. General Accounting Office, “…if Geothermal Heat Pumps were installed nationwide, they could save several billion dollars annually in energy costs and substantially reduce pollution.” It is time to start doing what is necessary to move us in the right direction.

My wife and utilized geothermal in our post frame home and are glad we did. Even if you are not planning upon climate controlling now, read more about how to prepare for the future here:  https://www.hansenpolebuildings.com/2016/08/pex-tubing/.