# Killing the propane bill



## LadyHawk77 (Oct 11, 2011)

My goal for solar has always been to kill my propane bill. My home doesn't use much electric. What gets me is propane. I fill my tank 3-4 times a year since we run our radiant floor heat with it. This year I decided to try and beat the system and boy am I glad that I did! Especially now that my county is OUT of propane until March!!!

My system is 3 fold. First we have 3 hot air panels on the south side of the house. I picked them up off of craigslist for nearly nothing. They are run off a snap switch and two 12v computer fans. One sucking air from the house into the panels and the other pushing the heated air from the panels into the house. On a normal day I get temps near 200 degrees coming out of the unit. Today it was -6 and it was heating air starting at 60 degrees and spitting it out at 80. Not a big gain, but at -6, I will take it!!!








Phase #2 and #3 both feed a hot water tank. I picked up a new electric tank for free from a guy that installed it in a home to find out that it wouldn't heat. It sat in his shed for 3 years. It had the original element in the bottom and was missing the top heat element. I learned to solder off youtube and built a manifold to divert the water coming out of the floor to the extra tank before it dumps back into the propane run hot water tank that heats the floor. I used sharkbite on the ends for easy disconnect (yes, I insulated the pipe after the pic was taken). 








I then re-wired my HF solar panels to 24v and sent them direct to the bottom element on the tank. The top element was replaced with a 12v hot water element. 








I got a 500w turbine from Missouri Wind and Solar ($100 cheaper off ebay than the website). Since it is winter and I couldn't pour a concrete pad and permanently install the turbine, we jimmy rigged it to the kids playset. It is freezing and they aren't using it! I had planned to wire the tubine direct to the 12 element but learned that is not a great idea. So instead I wired it to my battery bank. After the bank is full my Xantrex C-40 diverts the load over to the 12v element. This time of year I use my bank for emergency blackouts only.








How does it work? Well I am too cheap to pay the $40 to install the temp gauges. The hand test tells me the water coming out of the pre-heat tank is a lot hotter than the water going in. On windy or sunny days the propane tank does't kick on even when the pump is pushing water. I am also still on my 1st propane fill of the winter and I still have 60%. In my book, this is a win!

I know there are "better" ways to do this kind of thing. I am sure many of you have ideas on this. This is a hobby for me. A hobby that was not supported by my husband until he watched propane hit $5 a gallon  I have had to build this on a shoestring budget and have had fun doing it. For me that works!


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## wy_white_wolf (Oct 14, 2004)

Looks nice.

One comment on the 200 degree air coming out of the air panel. You really should increase airflow to bring this down. That hot is dropping the efficency of the system and could cause a fire danger. Air panels should have about a 30 degree variation over the inlet and outlet temperatures.

WWW


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## SolarGary (Sep 8, 2005)

Nice job!

In the long run, you might look into a solar thermal water heater rather than the PV water heating -- they are about 4 times more efficient, and cheaper. You could put the PV you free up to work on the house electric bill.

They are a good DIY project -- pretty simple to build. Several people on this forum have built them.

A couple to look at:
http://www.builditsolar.com/Projects/WaterHeating/water_heating.htm#1KSolarWater

This one does space and water heating:
http://www.builditsolar.com/Projects/SpaceHeating/DHWplusSpace/Main.htm

More stuff here:
http://www.builditsolar.com/Projects/WaterHeating/water_heating.htm

Gary


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## topofmountain (Nov 1, 2013)

Sounds like a big win to me. Nice write up thanks


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## biggkidd (Aug 16, 2012)

Good Job I just love stories where people are winning the fuel war!! Keep up the good work.

Larry


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## fishhead (Jul 19, 2006)

Good job!

You're doing what I plan on doing when I build my new super insulated house. No cutting wood and no monthly gas bill. A year or two of gas bills would buy a lot of materials to make collectors.

I had no idea you could generate 200 degrees.


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## light rain (Jan 14, 2013)

Thank you for sharing your knowledge about this. The pictures help tremendously. I will sit down today and show this to my husband and we can discuss what we could possibly incorporate into our house. Like you, multiple lp fills are getting weary. We will also upgrade our insulation wherever we can. We have 2 south facing windows on our addition and the west side is protected by main part of the house.


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