How Many Tankless Water Heaters Do You Need in Your Laundromat?

I read the discussions about replacing old water heaters using the tankless water heaters available on the market today. They’re easy to replace, exchangeable in a few minutes and very price competitive. There is a wide range of opinions on the number of these heaters that should be installed in a Laundromat for those who elect to use tankless heaters.

The benefits go beyond price, including no need for a storage tank. The big cylinder of steel that holds hot water and radiates out expensively purchased heat through its steel shell. Constant cooling and then reheating is considered by many to be a waste of precious money. Keeping in mind that approximately half of your gas bill is devoted to heating the hot water in many stores with heater and tank combo systems, sounds like something to seriously consider. Insulation of the tank, with double insulation on the top, (where more heat is lost) can help with systems that have tanks, but tankless doesn’t need to face this heat preservation method.

Because tankless heaters use smaller interior tubing or exchangers the build-up of calcium and magnesium produces interior pipe insulation (lime buildup) over time is operating on all water heaters, but is more noticeable in the tankless models. A well-designed tankless system will make deliming these heaters a fairly simple and easy maintenance procedure.

There are also arguments about how many tankless heaters should be installed in a Laundromat to handle the volume of hot water needed. I organized a simple Excel spreadsheet to calculate the hot water demand of your Laundromat which I have attached to this post. I don’t know how to post the Excel version that allows you to only enter the red numbers on the sheet (number of washers and water use) and automatically produces the result needed.

I do suggest that whatever number of heaters this program suggests, you add the plumbing and hookups needed for one additional heater. This way you have an easy way to add capacity if you’ve underestimated demand because you’ve added additional wash or rinse cycles, or the usage on the brochures was in error. You can also turn off (and drain) any heater you don’t need if you’ve overestimated demand. This saves money and preserves the unused heater.

Here’s a PDF Excel sheet calculating how many tankless heaters you need. Hope it helps someone. Send me an email and I’ll send the operating Excel version. Laundromat 123