System upgrade: adding a heat exchanger and pump
August 21, 2008. Time Invested today: 1:45 Add an external heat exchanger and pump
After 2 years of watching my dashboard display in the kitchen I have decided that the system could be improved. The maximum temperatures I would see at the top of the storage tank on a clear sunny day would be 90F and often in the low 80’s. I decided that the weakest link in the system is the Solar Wand itself since it only has about 2 sq. ft. of surface area to transfer heat.
I decided to add an external heat exchanger with nearly 3 times the surface area. I researched heat exchangers and found a really good deal on eBay ($89.00) for a 20 plate, flat plate heat exchanger.
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This unit has stacked plates that allow the 2 fluids to interleave within. I built an insulating box for it out of 2 inch blue foam board wrapped in aluminum tape. I figured the foam might melt if it got too hot, so the tape should reflect the heat back. Also it just looks kinda NASA tech cool!
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I also found a good price on a 3 Watt El-Sid pump. This low wattage pump would not require that I add another solar panel to power it as I already have a 20 Watt panel running the original 10 Watt pump. The extra 10 Watts in the original design accounts for my northern latitude and gives a bit of headroom. Theoretically I should add another 5 Watt panel, but adding a mere 3 Watt load to the 20 Watt panel has not compromised performance as far as I can tell. In fact performance of the system is way up!
Isn’t this fun! Learning the skills necessary to build , install and maintain a home solar water heater can be fun to do and yet very economical. Taking it a step further, learning to build your own solar panels helps in creating independence for your self as well as saving the money on retail purchases. Doing the work yourself, saves on labor cost and increases your skills to maintain the functionality of your renewable energy system, rather than having to depend on outside sources for those things, further saving you money. Creating your own home solar system and doing the work necessary to make a sustainable living opens up many possibilities for finding work , if that a need,or just satisfying your own sense of purpose. Having your own home solar power or wind power generator creates freedom from every increasing utility bills, leaving that much more financial resources for the next fishing trip or vacation. Look into all the possibilities at the Shifting Solutions web site.
tomorrow we continue – 3 days left