Weaning off the grid

I would like to increase our pool heat pumps performance and efficiency on cool but sunny days in spring and fall and it looks like a solar collector and absorber on our roof could help do this. As well as heat our hot water tank with any excess heat during warmer months.

For now I installed our 80K BTU pool heat pump on the south side of our house where it was closer to run the thick low guage electrical wires back to the panel and were we get more direct sun and heat which gets trapped somewhat by the house.

Right now during the pool season I use a MacGyver setup with cardboard and thin plywood sheets covered in large thick black garbage bags against the house a couple feet behind the heat pump intake. It only covers about 5 sq ft but when the sun shines on a 15°c day in the spring or fall I get about 26°c air going into the heat pump and 3°c going out which is pretty good and helps heat our 60K liter above ground pool several degrees during the day. Doing this can get it to about 28°c to 30°c without needing to run at night when it has to work harder and use more power due to less heat in the air and if needed reversing periodically to defrost the coil.

I use a timer to run the water pump just during the day and the heat pump only runs when water moving through it.
This setup improves efficiency, extends our normally short pool season and saves us $100’s compared to direct electric or gas heating and is better for the enviroment.

The problem is if the outdoor temperature is lower than about 15°c or not that sunny and drops down to much at night there is to much heat loss from the pool even with solar cover for the heat pump to bring the temperature back up enough during the day. Here is where the solar collector and absorber can help boost the heating performance and effeciency with minimal operating cost. Also I am thinking about using foam panels thatcould be made low cost using discarded packing material from stores or ….and attach to the pool wall except during the hot summer period to reduce heat loss as well as thicker cover for spring & fall.

Also in peak of summer with the pool solar cover on when pool not in use to reduce evaporation and minimize dirt getting in, the water can get too hot so this heat can be used to heat our hot water tank and if possible other uses or vent it.

I got some ideas from the article below (see the diagram in it) but need to do some more research to see what is needed and the cost vs. savings to see if it worth while. I can get my nephew over who is learning heating & A/C in school and on the job to see what he thinks and also have a few other people I can talk to.

It possible to connect our A/C in the loop but probably little efficiency gains for the effort and cost as our house is fairly well insulated including more we added in the attic and we usually only use A/C when it is very hot outside and that is when the pool doesnt need any more heat.

Then later look at more solar to reduce or replace power requirements of our heat and water pump etc…. Then later add more solar & home battery bank and maybe ground geo thermal loops to help heat house & pool and power the house.  Or fuel cells when these more efficient and affordable for homes and vehicles.

http://www.rehva.eu/publications-and-resources/hvac-journal/2012/052012/field-test-of-a-novel-combined-solar-thermal-and-heat-pump-system-with-an-ice-store/

About Kevin Yaworski

I use my blog to write about things I find interesting or that I think others should know about.
This entry was posted in Health and wellness, News and politics, Sustainability and tagged , , , , , . Bookmark the permalink.

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