I recently added the "Pool Heat Transfer Tools" spreadsheet to my list here if anyone is interested. I have been working on this one for some time and attempting to calibrate the results against my own pool. It gets pretty close to actual pool water temperature. Here is a list of features:
- Heat Txfr - Estimates heat loss and gain from a full heat transfer model that includes the effects of the sun, solar panels, NG heater, heat pump, and environmental conditions. It downloads weather data from the internet based upon your location so an internet connection is required. It will also estimate the amount of water lost per day/week due to evaporation.
Heaters - Compares operation costs of NG heaters and Heat pumps in a simpler format than above.
Pipe Loss - Estimates the heat loss from a pipe with or without insulation.
Pipe Freeze - Estimates how long it would take for a pipe to freeze.
One of the biggest challenges was to get the Sky Temperature estimate correct for the radiative losses. There are many models for this but the one that seemed to work the best for my situation was to measure my own sky temperature and calculate the emissivity . Unfortunately, this may not work well for all locations which is why I would be interested in other's experiences.
Most of the formulas used are from established sources such as: RSPEC
Download Pool Heat Transfer Tools Here
Keep in mind that this is still a work in progress and far from perfect but feedback and suggestions are always welcome.