Makeshift Solar Water Heating
Question received by Solar Power Authority on July 11th 2008: South Padre Island Texas area--winter temp 40-50-60 degrees--took a fast food carry out plastic container black bottom half clear top half filled with water put in sun 2 hrs later to hot for finger---outside temp. 90 degrees---clear cover covered with water drops still worked--any thing wrong with this concept--then took foam cooler painted black inside put 50 lb. water @ 80 degrees in cooler covered with clear plastic end of day picked up 36 degrees--averaged 1100 btu per sq foot collector area--will this concept work in winter?
While this question is a bit challenging to read we always do our best here at Solar Power Authority to answer questions as best we can! With that in mind we get the general idea and have put together our thoughts below. As always, we encourage the community to take a shot and add their own comments below. For anyone with your own question just go to our Ask Page.
First off, it's hard to know the intentions of this question but it sounds like this person wants to generate heated water using solar energy. We suggest using a commercial solar collector because it's not clear how one would get the heat from a fast food container, or even a larger plastic device into a living space without facing leaks and other challenges. That said, if this water is not being used to heat a living space then it might be a very affordable way to heat water - simply using a plastic container with a clear top and black bottom. In general though, be careful not to ingest paint or other chemicals used to color your solar heating container. Chemicals such as Bisphenol A (BPA) which may raise the risk of certain forms of cancer. Below is a picture of a professional solar water heater mounted on a roof:
Back to the question... Since the sun shines for fewer hours per day in the winter than in the summer and is lower in the sky (in the northern hemisphere) the home made solar water heater definitely won't work as well during those months. Also, there will be more thermal losses occurring in transport of the water (now referring to a professional solar water heater) due to conduction and convection of heat from the water to the atmosphere. This will occur when pumping the water through the plumbing to go from the solar collector to the living space in the winter because the outside temperature will be lower.
While this question is a bit challenging to read we always do our best here at Solar Power Authority to answer questions as best we can! With that in mind we get the general idea and have put together our thoughts below. As always, we encourage the community to take a shot and add their own comments below. For anyone with your own question just go to our Ask Page.
First off, it's hard to know the intentions of this question but it sounds like this person wants to generate heated water using solar energy. We suggest using a commercial solar collector because it's not clear how one would get the heat from a fast food container, or even a larger plastic device into a living space without facing leaks and other challenges. That said, if this water is not being used to heat a living space then it might be a very affordable way to heat water - simply using a plastic container with a clear top and black bottom. In general though, be careful not to ingest paint or other chemicals used to color your solar heating container. Chemicals such as Bisphenol A (BPA) which may raise the risk of certain forms of cancer. Below is a picture of a professional solar water heater mounted on a roof:
Back to the question... Since the sun shines for fewer hours per day in the winter than in the summer and is lower in the sky (in the northern hemisphere) the home made solar water heater definitely won't work as well during those months. Also, there will be more thermal losses occurring in transport of the water (now referring to a professional solar water heater) due to conduction and convection of heat from the water to the atmosphere. This will occur when pumping the water through the plumbing to go from the solar collector to the living space in the winter because the outside temperature will be lower.DIY Solar Pool Heater
This morning one of our readers sent us a little do it yourself tip for heating a swimming pool based on what one of her friends is doing. The full comment follows: "Not a question, but a little info: Knowing how hot the water gets in a garden hose, a friend with a swimming pool bought a bunch, I do not know how much, of black garden hose. She spread it out in big curls on top of a nearby flat roofed building. She then fixed up a small recirculating pump, ran the water to the swimming pool to warm...Headlines:
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