New natural gas heater

[JamesW]

The fact that a pool heater needs a special HP line if true perhaps has more to do with the pipe run length?

Line capacity depends on diameter, length and pressure.

Normal residential pressure is either low pressure (0.25 to 0.5 psi) or higher pressure (2 psi).

Appliances usually use low pressure, so if you use 2 psi, you need a regulator near the appliance to reduce the pressure to the appliance pressure as specified by the manufacturer.

 

[pktaske]

So bigger pipe is better right? 2 inch would work best I guess?

 

[JamesW]

So bigger pipe is better right? 2 inch would work best I guess?

There are charts that show line capacity for different pipe sizes, pressures and lengths.

You size according to the required volume and length of pipe.

There is one size for 2 psi and one size for low pressure (about 0.25 to 0.5 psi or about 7" w.c to 14" w.c).

 

[PoolGate]

Gas operates on such low pressure to begin with. I have 2 furnaces, a gas dryer and a professional range. All routinely are on in the winter at the same time. The fact that a pool heater needs a special HP line if true perhaps has more to do with the pipe run length? Why wouldn't any volume issue simply be solved by a using a 1" gas line?

The proper amount of gas needs to be supplied. Lower pressure and larger pipe or higher pressure and smaller pipe. Whatever way you get there. I have 2 gas furnaces, a gas water heater, 2 gas fireplaces and a gas stove and my pool heater uses more than all of those combined.

Where I live the heavy up from my gas company was free. So them putting a high pressure port on my meter allowed my gas installer to put smaller pipe (77 feet), saving me money.

 

[johnnydot]

Gas operates on such low pressure to begin with. I have 2 furnaces, a gas dryer and a professional range. All routinely are on in the winter at the same time. The fact that a pool heater needs a special HP line if true perhaps has more to do with the pipe run length? Why wouldn't any volume issue simply be solved by a using a 1" gas line?

I have a Hayward 200 natural gas heater fed by a 3/4 pipe that runs 75 feet that I tapped off of my furnace line that runs great.

 

[UKjames]

I’d look at the efficiency of the heater as well. There’s quite a range.

Depending on how close to your house you can also use your central heating boiler to heat the pool. That’s what I do.

 

[ajw22]

Depending on how close to your house you can also use your central heating boiler to heat the pool. That’s what I do.

…and size of the pool.

My house boiler is 250K BTU. My pool heater is 400K BTU.

My house boiler would be sub-optimal to heat my pool.

 

[UKjames]

Yes I thought that after adding my post.

Another factor is ambient temperature and duration of pool use in the year. As day/night temperatures drop, a bigger heater is needed to maintain temperature

Noting the above, I assume your measurement of size is 35,000 is gallons rather than litres?

 

[ajw22]

Noting the above, I assume your measurement of size is 35,000 is gallons rather than litres?

35,000 GALLONS

 

[UKjames]

i thought that might be the explanation!