couzin2000

Really??? NO ONE can help me here???

I have been working on a tool for weeks now. It's a calculator of costs for the monthly/yearly consumption of a spa/hot tub. I want to have certain information input on one end, and the other end must produce results. I've been looking for help within many scientific communities, and I have managed to find many formulas that will permit me to calculate a part of the consumption. But somehow, something is wrong within the calculations, and I'm looking for assistance. Warning: this thread is not for the average run-of-the-mill discussion: I am looking for scientific data here. Many factors come into play here: temperature of the air, of the tub (shell), of the water, and at different times of the year. I have temperature data, so this is fine. Ozone generator, hp of the massagers, the filter's pump, and so on, all of those aspects are already calculated. However, I am looking for the data for heating the water. Since I'm not in the US (Quebec, Canada), temperatures here are different: July is warm with an average 19.8°C. January is snowy with -12.5°C on average. I've managed to calculate the consumption of heating water from x° to y°. In essence, here is the formula: Q(energy, in kWh) = (1.155e-3kWh/liter-°C, the heat coefficient) x volume of water (liters) x temp.differential (end temp - start temp, in °C) This gives me the consumption of elevating the water temp to the desired level. However, I can't figure out how to calculate the costs of maintaining the temperature constant. I've managed to calculate heat loss, but that gives me a value that is not consistent with the amount a spa should cost here in Quebec (which varies between 600$US to 1500$US per year). If anyone can give me some help here, it would be much appreciated. Here are some things you may wish to consider when calculating: the spa is always square; I do not calculate in-ground or above-ground; the cover is closed at all times when not in use; insulation is not a factor, and all spas have the same for this problem; I'm looking for kWh (kilowatthours), not joules or time to heat the tub. Thanks in advance for everything! Couzin2000