Natural gas pressure drop, pipe sizing and pressure

I bought a 200,000 BTU pool heater, to be installed outdoors.

The model is Hayward H200FDN.

The size of the pip ``Based up ``Hayward will not be responsible for heaters that soot up due to improper .. natural gas line sizing''.

If I cannot provide this heater with adequate gas flow, I can upgrade most of the piping from 3/4" NPT to 1" NPT, it is roughly a day or work and some money.

To question is, do I need to do it?

So, I thought, I could turn to measurement of the gas pressure right at the inlet of the pool heater. If the gas pressure at the inlet, when the heater is running, is above the recommended value, then I am fine.

I do have a pressure gauge that I could use.

My question is, and here's where I am not sure, what is that "recommended inlet pressure". Is that 0.5 PSIG when the heater is running? Am I reading that right?

thanks

Reply to
Ignoramus6769
Loading thread data ...

I think you are interpreting it correctly. But, 0.5 psig seems high for regular natural gas. Or, is it propane? Either way, 1 psi is 27.7 in-wc. So that would make the inlet pressure almost 14 in-wc. But as most gas appliances have regulators, I guess that might be ok.

Reply to
Art Todesco

You are correct. You need the pressure at the appliance when it is running. With the appliance NOT running you would have the correct pressure on even a 1/4" line.

Reply to
clare

I agree. It makes sense based on simple physics.

The question is, what exactly pressure should I see on the onlet when the heater is running.

i
Reply to
Ignoramus6769

...

"...an inlet gas pressure of 0.5 psig or less ..."

It's not any _specific_ pressure; it's that it's not too high and that whatever it is can be maintained under flow conditions.

Reply to
dpb

On Sat, 16 May 2015 11:40:50 -0400, snipped-for-privacy@snyder.on.ca wrote in

+1
Reply to
CRNG

Isn't there a pressure regulator near the meter at entry point.

Reply to
Tony Hwang

OK, an update: I have decided that

1) This is a very good heater because it can heat the pool quickly before use, and thus I do not need to waste energy "maintaining" temperature when the pool is not in use. 2) I need to hook it up correctly and will install proper gas piping comprised of about 40' of 1" pipe. i
Reply to
Ignoramus4261

Before you plumb it all in, have you figured out how much it's going to cost to heat the pool? Around here, NJ, almost no one uses them because of the huge operating cost. They have them sitting there, because they were installed with the pool, but they rarely if ever use them. I guess if it's small, it might not be too bad. But for an inground one that's 30 or 40K gallons, which isn't unusual, it costs a lot of money. The fact that it's 200K BTUs tells you something. The largest home gas furnace is 120K btus.

If you have some room for a solar array, you can operate it for close to free. But they have drawbacks too, the large size needed being one. Whether you want one on the roof or have a space out of sight in the yard is another.

You can use a pool cover with either, which helps a lot. But that's a pain and some folks won't put up with it, don't like the look, etc.

Reply to
trader_4

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.