What type of water heater is most economical

[area123]

This is a three bay self serve with fairly low traffic right now. Location is SE kansas. Currently the wash has 1 electric and 1 gas 50 gallon heater. We are curious if a tankless would be more efficient. I know there are a lot of variables to consider that I dont know yet. Cost of gas vs electric and I'm sure many other variables. Just wanting to get an idea of the general consensus.

We also feel that the utility cost to sales is a little high. I think on average gas electric and water are about 60% of sales alone. With water being about 10%
Thanks!

 

[Randy]

We use a gas on demand water heater, one for each bay and only heat the High Pressure soap function.

 

[2Biz]

We are curious if a tankless would be more efficient. I know there are a lot of variables to consider that I don't know yet.

Do your homework if you decide to go this route. Some demand heaters are full flow and MOST energy efficient ones will restrict water flow to achieve a preset temperature. "Advertised" flow can be a lot less..... You need to read the fine print!

 

[area123]

Definitely doing some research.

What gpm of hot water will I need on average for a 3 bay wash? I have not very often seen all 3 going at once but I know we should design for that. I have been there on a busy day to wash and have not had very warm water so I know the 2 50 gallon heaters are not enough, even though I feel the utility bills are way too high for the sales. There is no insulation on the tanks or pipes so maybe that would help. Gas heaters definitely have a quicker recovery than electrics. I know, a lot of things to do consider. And since we are coming up on warmer weather the hot water bill will be much lower so we have a while to study the problem.

 

[2Biz]

Generally pumps running 1200 psi with a 2506 nozzle, you'll see about 3gpm flow per bay. Do you know if they heat all the water or just the soap cycle?

I'm going to throw this out there...They sell Ultra High Efficient Water Heaters that are like a hybrid. They are like a demand heater but also uses a storage tank. The one I have is 55 gallon, stainless steel, has 1" npt fittings, is full flow, heats about 360gph of 100° water, and is vented with PVC...It will do this all day long. I have a 4 bay, have ran over 3000 gallons through it in a single day and did not run out of heated water. No danger of starving a pump...Something to consider.

 

[wash4me]

If you're going the tank route you may as well just get a 199000 btu tank unit. Simple and no maintenance. On another note why do you have an electric water heater and a gas? I would either feed the electric with hot from the gas or just eliminate the electric. It's easy to get the wrong answer by doing the gpm flow btu math. There is a tremendous amount of adjustment needed for all the times hot water is not running for one reason or another. I have a 6 bay self serve with one automatic and we have 250000 btu and a 119 gallon storage tank that keeps up just fine. Outside lighting that runs all night and that electric hot water heater are probably your big energy wasters. How is the equipment room and trough heated? If it's electric figure out how to make it gas. (I assume you have natural gas and not propane)