Uma linha de gás natural 2 PSI será suficiente para um aquecedor de água sem tanque?

Question

Uma linha de gás natural 2 PSI será suficiente para um aquecedor de água sem tanque?

#1 resposta do (2 votos)
#2 resposta do (0 votos)

2

I'm planning on installing a tankless water heater that maxes at 160K Btu. I only have a 1/2" line from the meter to the furnace(75K) in the same room. The city told me that there is 2lb gas from the meter to the house. The sizing charts that I found say that 1/2" 2psi black pipe will handle the btu draw for both the furnace and the water heater. I know I will need to use a regulator at the water heater to step down to 7" w.c. or so. I will also need to adapt the 1/2" line to 3/4" for the water heater. My questions are:

1) Will the 1/2" 2lb line be enough? 2) Should I convert to 3/4" before the regulator to the water heater?

Obrigado por qualquer entrada.

gás natural sem tanque

por Chuck W 07.03.2019 / 20:25

2 respostas

Tags gás natural sem tanque

Carteira de motorista internacional nos EUA Posso aterrar com segurança uma luminária se a caixa do teto tiver dois fios quentes e um neutro (sem fio terra)

score 2 · Answer 1

2 psi!

Where do you live? Yes 2psi on 1/2" iron can deliver your stateted load a whopping 250 feet!

You can use a 1/2 in regulator down to 7" up to about 15 feet before the tankless. And reduce at the unit.

Also check the tankless for acceptable input pressure, you pode not need a reg but most likely you will.

Something like this is totally acceptable not in reference to code

score 0 · Answer 2

If the tables say the existing 1/2" piping will supply what you need (assuming 2 psi all the way to the appliance), then I would just go ahead and install it with the existing gas piping. But be sure there is not a regulator just where the gas line enters the structure or up in the attic that drops 2 psi to 7" W.C. (0.25 psi). I would check with the builder or city permitting office.

What kind of water heater was installed before--what size burner or was it electric?

We have 7" WC gas from the meter. Our 13 year old very basic Bosch Aquastar tankless NG fired WH (~117 kBTU/h) came with a regulator which I had the plumber leave in place, but maybe the one our Aquastar came with accepts only standard low ~7" WC input. Alternatively, maybe this regulator is not needed for 7" WC input. IIRC the installing plumber thought that he should remove the regulator, but I nixed the idea because I could not find any statement in the installation instructions to the effect that the regulator was not needed if the house supply was 7" WC. I had bought this WH at a big box and carefully read the instructions intending to install it myself, but I thought better of it and hired a plumber.

A new tankless WH like yours might come supplied with a regulator which accepts 2 psi gas input. Check the instructions.