Looking For Green Options

[BTT]

Hello All:
We're remodeling our house, including radiant-heat for the floor. The question is how?
Located in south-central New Mexico, we are at 4,200 feet, but only 60 miles off the premier solar footprint of the country.
We also have a hot mineral well that provides sufficient water temperature to heat the winter floor (100 degree).
We've adopted the "live green" philosophy wherever we can afford to make the best sustainable choice and there appears to be little cost difference between the two heating methods using a closed loop system of PEX in the floor with a small solar circulating pump.
That said, I'm hoping to connect with Others, who take a "guerrilla economics" approach to life-style projects. Using the above for example: the only way the two methods of heating the floor could cost about the same would be if the solar collectors were virtually free. And, they can be; although sometimes not as attractive, they certainly are equally effective and come with very little to zero cost, other than a little time spent using simple DIY skills.
Any green (or other) thoughts appreciated.
BTT

[Stevenc]

First of an foremost -- I am not a plumber or HVAC person by trade. I study allot of this information out of interest and deal with with HVAC, plumbers, pipe-fitters for a large condo association (our mechanical systems are more like commercial buildings than residences).

The hot mineral springs -- it sounds like you want to use this as an open loop system and pump the hot water through the radiant flooring to heat the home. Three issues --

1. The 100 degree temp is hot, but you would be using allot of water to get the floor to the home to a decent temp.
2. What are you going to do with all that water? The mineral water could be used at other areas of the home, but it sounds like you would need a second well to pump the water back into the ground -- (open loop geothermal systems do the same thing).
3. Long term concern would be the maintenance of that system -- hot mineral water typically has lots of minerals in them that would cling to inside of your piping material and eventually slow the flow, or clog piping.

Solar panels sound like a much better way to go. Closed loop, treated water to lower maintenance costs, etc.

Good luck with the "guerrilla economics" building tactics.

[jessy]

Other thoughts?
As far as the PEX tubing and heating the floor there are a few different options that i’ve used. Don’t have links or product names handy.

The one I like the most is a sheet of metal that you staple under the sub floor that has 2 channels that the tubing will snap into. After the tubing is installed the insulation goes in as normal. The metal helps to spread the heat over a 10” wide section of flooring and could be a DYI project.

I have stapled the tubing on top of the sub floors and had a company pump a self leveling product about 1.5” thick. It gives you very even heat and is a great heat sink, but dose not fit the DYI.

I have seen a foam looking product that is laid over the sub floors that has channels for the tubing to be installed. This limits the flooring choices to a snap/click floor or putting down a thin sub floor before putting down carpet. I know of one person that has installed this in there house and there unhappy with the evenness of the heat. I don’t know much about it and not sure if I would suggest it, but dose fit the DYI if you plan on putting down all new flooring.

A different suggestion would be to update you inside heating unit. Getting a good unit with a variable speed fan and a water to air heat exchanger might be better.


Some home owners of houses I have flipped have had issues dust, humidity, and slight smell issues from the lack of air circulation/filtration. The issues were fixed by installing a different HVAC controller that would run the fan for 15 minutes every hour.

[Dana]

Closed loop can be done with the 100F well water too- a geothermal heat-pump heating/cooling designer would be able to calculate how much PEX you'd need below the water level in the well to provide the necessary heat exchange (but I'm thinkin' it wouldn't have to be much, since you're not talkin' huge delta-Ts with the wrong sign, the way you are with heat-pump geothermal.) The simplicity & reliability of it is much too good to pass up compared to solar.

This is done all the time in Iceland, but finding a good technical resource might be tough.

I'd start thinking about pre-heating all of your DHW with the 100F well too. You can't let potable water stagnate at 100F (legionella hazard, etc) but with a simple low-volume potable-side pass-through heat exchanger in a tank of 100F water (like say one of the smallest/cheapest Turbomax, Everhot EA series, or Ergomax reverse-indirect water heaters) letting the tank's aquastat operate the geo-well loop pump would give you 3/4 of the heat for hot water for the cost of occasional pump cycles. Then a very minimalist solar DHW system could take it the rest of the rest of the way to 120F+. You wouldn't need much panel, OR much tank to make it happen. You might be able to get creative using a somewhat bigger reverse-indirect as both your solar store and geo, with the 100F well being your fall-back DHW temp if somebody decides to fill the hot tub at night.

[Angelb]

Based on experienced it is not hard to adopt Live green, well just come to think of the money you will save than you're usual budget plus the fact that you can help to balance natural resources