Sizing a gas heater

[Ready2swim]

We are in the process of building a new pool at our new house but I can say that my old pool was about the same size and we had a 400,000 BTU unit that would heat the pool very quick...it would also heat up your wallet at the same time. The last time I calculated the cost it was around $80 to heat the pool to 85F. When running the Spa (8' dia) it would only take about 30 minutes to heat up to about 102F

I am in Houston Texas and the water isnt very cold to begin with in the winter but it is too cold for me to get into it without a heater.

[tenax]

many companies make a 150,000 btu heater at a minimum..even with my very old (80s) 150,000 teledyne laars, i never have to use maximum heat output to get to between the 85 and 90 we like for our pool..i've just been sizing as i need a new one and my pool is about 15 x 28 and a 125K laars jandy is quite adequate to the task..the H series hayward i looked at starts at 150,000 which will be overkill..plus, i don't hear great things about the hayward..i figure if a teledyne laars can last 20 years plus in my pool..really, can someone expect anything more out of a furnace than that? especially given how tough a pool is on it!