Running out of hot water... Please Help!

[Partyman Joe]

I own a catering business and have moved into a new facility and need some advise. I need to run two commercial dishwashers and occasionally simultaneously and not run out of hot water. They both require about 1 gallon per cycle and run about a 1 minute cycle. Typically only one washer is running at a time. Natural gas is available but no 3 phase power. Which direction should I go to accomplish not running out of water. For a commercial tank size and BTU's?

I've looked into a gas booster heater $3k +, but still run into the issue of needing to feed it 120+ degree hot water.

I've had people tell me on demand hot water system would work best, boosters are the way to go, as well as commercial tanks will take care of me. Help! I'm sick of scrubbing dishes!

[jimbo]

You need to know the total gallons per minute, and gallons needed per hour, and the temperature you need. Then, any of the water heater manufacturers will have guidance on selecting a unit.

Get out the checkbook, because this won't be cheap. A 100 gallon, 200,000 BTU unit will run about $4700 plus labor. It needs a large gas supply, and a 6" vent through the roof. It will give you about 200 gallons per hour heated to 100º above incoming. I can't tell from your description if you need this unit, or something smaller.

[Partyman Joe]

Jimbo,
Thanks for the thought and the info. I would say that I would need no more than 75 gallons of water/hour. Max. Typically the machine runs about a minute (75 seconds safely) per cycle and specs say a gallon of water per cycle. 99% of the time only running one machine. Water coming in is pretty cool, I would say 50-60 on average. Final wash temperature should be above 160-170 degrees. Is there any brands that you are familiar with that are good quality that I should start making calls to for pricing. With this info, do you have any new recomendations? Thanks again! Joe

[hj]

A75 gallon, 80,000 btu heater would give you a first hour rating of 130 gallons and a recovery of 60-80 gallons per hour depending on the incoming water temperature. Which should be more than adequate for you needs. Set it to the 160 degrees you need for the kitchen and use a tempering valve to reduce it to 120 degrees for personal use.