Will an electric water heater keep up with demand for rinse?

[wrightwash]

Early on in our car wash rebuild, I had planned on utilizing an existing new 60-gallon electric water heater to heat the soap/wax supply tank water.

I discovered that this would not work, the soap and wax feed from a 1/4" line that tees into the main 1/2" rinse supply line to the pumps. The hot water from soap and wax mixing with the room temperature rinse water would only slightly raise the water temperature if any.

Right now I'm running 1" PEX from the main city water line into the rinse, through a 1" Walter float valve into a 40-gallon tank.
The mixing tanks are fed with 3/4" PEX branches off the main.
This is feeding 5 CAT 430 pumps (5 GPM each).

Running directly through the water heater to fill the rinse tank seems like the only way I will be able to heat the water with my current setup. I'm afraid the 3/4 ports on the heater will not allow for enough flow to keep the required supply of water in the tank though.

Does anyone have a similar setup to this? Would the 3/4" keep up with demand or should I do the heating on a kidney loop?


I attached a schematic of my current plumbing for reference.

 

[washnshine]

Early on in our car wash rebuild, I had planned on utilizing an existing new 60-gallon electric water heater to heat the soap/wax supply tank water.

I discovered that this would not work, the soap and wax feed from a 1/4" line that tees into the main 1/2" rinse supply line to the pumps. The hot water from soap and wax mixing with the room temperature rinse water would only slightly raise the water temperature if any.

Right now I'm running 1" PEX from the main city water line into the rinse, through a 1" Walter float valve into a 40-gallon tank.
The mixing tanks are fed with 3/4" PEX branches off the main.
This is feeding 5 CAT 430 pumps (5 GPM each).

Running directly through the water heater to fill the rinse tank seems like the only way I will be able to heat the water with my current setup. I'm afraid the 3/4 ports on the heater will not allow for enough flow to keep the required supply of water in the tank though.

Does anyone have a similar setup to this? Would the 3/4" keep up with demand or should I do the heating on a kidney loop?


I attached a schematic of my current plumbing for reference.

Even if your plumbing plan keeps up with demand, I would double check to make sure an electric water heater has the recovery time to keep you up to temp. I don’t have experience with electric heaters, just natural gas, so the other members can chime in, but I would consider that too.

 

[wrightwash]

Even if your plumbing plan keeps up with demand, I would double check to make sure an electric water heater has the recovery time to keep you up to temp. I don’t have experience with electric heaters, just natural gas, so the other members can chime in, but I would consider that too.

I agree, this one shows 70 gal/hour for demand at factory temp settings. With heavy use that could be an issue too.

 

[MEP001]

I think he's only concerned with flow, which I think would be fine as long as the water pressure is good. My main water tank is fed from a 1" line through a six foot stainless wrapped water heater hose, which is less than 1/2" ID, and with all six bays running it stays full. As long as the pressure is good and the connections to the heater were as short as possible (They are full 3/4" ID) there should be no flow issues.

Definitely won't heat enough water to keep up with demand, though.

 

[Toms PTcarwash]

If the water heater can handle the flow rate without too much head loss (you need to determine what that is in GPM) you can then figure what temperature rise you require.
Then convert that to BTU/hr. There are commercial water heaters that can handle very high demand, but if this is a residential water heater i doubt it will do it.
1KW of electric is about 3400 btu, most residential water heaters are 5kw (5000 watts) that is 17,000 BTU. I have a 250,000 btu boiler for my hot water.
So do a bit of legwork to be sure you have what you need.