I have a 32500 gal pool, 20x40 (800 sq. ft.). Most pool heater sizing charts would recommend a 300-400KBTU heater, even adding in the quip that bigger is better.
However, the previous owners of the house had a pool heater. It died, and they removed it. Gas line and electric are already there. However, they installed a 3/4" gas pipe. With a run of over 80 feet, we've calculated that the best we could do would be about a 200,000BTU heater. We have a solar blanket, and I would be quite diligent about keeping it on when the heater is running. I've been told that a BTU of heat added to the pool is a BTU of heat added to the pool. If that is true, and the blanket will keep most of the heat in, then is it a true statement that the only disadvantage to a smaller heater would be that it would take twice as long to raise the pool by X degrees than a 400K unit? It would also be a true statement that both the 200K and the 400K would burn the same amount of gas to raise the pool by that X degrees?
However, the previous owners of the house had a pool heater. It died, and they removed it. Gas line and electric are already there. However, they installed a 3/4" gas pipe. With a run of over 80 feet, we've calculated that the best we could do would be about a 200,000BTU heater. We have a solar blanket, and I would be quite diligent about keeping it on when the heater is running. I've been told that a BTU of heat added to the pool is a BTU of heat added to the pool. If that is true, and the blanket will keep most of the heat in, then is it a true statement that the only disadvantage to a smaller heater would be that it would take twice as long to raise the pool by X degrees than a 400K unit? It would also be a true statement that both the 200K and the 400K would burn the same amount of gas to raise the pool by that X degrees?
