I am installing an under floor water heating tubes. I will heat a tank of water with a solar collector and then as the temperature drops circulate the heated water under the flooring.I have a ~ 1000sqft to heat.IF the coldest temperature gets down to 25 Degrees Farenheit (-5 C) what mass of water will I need and how many square feet of solar collector will I need to achieve an even 70F all for about a 14hrs of no sun.A reference source would be great.
In general, it is not so much water to have in the tank as it is to have the collectors area determined. If you oversize the collector area, that is better than undersizing them. There are some rules of thumb for sizing heat sources, and usually that is to multiply spare footage by a certain number.
