Questions on Air Conditioning

**Motley** · 06-15-2015, 08:49 PM

I'm curious if mini splits are used in new residential construction or if a ducted HVAC system is still the best way to go in new construction? Also does anyone have experience with geothermal heat exchangers in OK? I understand they are much more effective in moist soil; in a drought with dry soil, they don't exchange heat as well, which can lead to inadequate cooling.

**bradh** · 06-15-2015, 08:56 PM

ServiceTech still around? I feel he should be able to nail this for you if he's still active on the boards.

**Rover** · 06-22-2015, 10:58 AM

Originally Posted by Motley

I'm curious if mini splits are used in new residential construction or if a ducted HVAC system is still the best way to go in new construction? Also does anyone have experience with geothermal heat exchangers in OK? I understand they are much more effective in moist soil; in a drought with dry soil, they don't exchange heat as well, which can lead to inadequate cooling.

Mini splits are what most of the world uses instead of window units or through-the-wall units (think motel). They serve one room at a time. You can buy "multi-splits" which are like mini splits except you can run multiple fan coil units (inside) using a single condenser (outside). If you are building new, ducted air systems are still generally the best way to go (using more than one for zoning if the house size is very large)

As for the geo-thermal, there are multiple configurations of the ground loop heat exchanger. If designed by a good trained and IGSHPA certified installer, you should be sized adequately for your climate. The piping needs to be grouted with proper material for good heat transfer. And, you are at least 6 feet under the surface for horizontal loops and most systems are vertical loops going 100-200 ft deep. Surface moisture is not of consequence, but soil type, water content, grout type, quality of installation, etc. is all to be figured in when sizing. If done professionally by certified people you should have no problems.

**Motley** · 06-22-2015, 11:22 AM

Thanks for the comments. I tend to research quite a bit before making decisions, and I ran across some negative reviews about soil types for geothermal. Looks like my ground is probably one of the worst for good heat transfer since I have dry, sandy soil, but I guess they can install more pipe to compensate. In SW OK, I know there are several people installing geothermal, so it seems to be increasingly used in this region.

**Rover** · 06-23-2015, 07:23 PM

Originally Posted by Motley

Thanks for the comments. I tend to research quite a bit before making decisions, and I ran across some negative reviews about soil types for geothermal. Looks like my ground is probably one of the worst for good heat transfer since I have dry, sandy soil, but I guess they can install more pipe to compensate. In SW OK, I know there are several people installing geothermal, so it seems to be increasingly used in this region.

If it eases your mind regarding climate and dry soil, I was involved in the installation of the first geo-thermal AC system in Saudi Arabia in Riyadh. It was a large villa installation and worked very well.