Tips for Determining the Right Size Tankless Water Heater

Tips for Determining the Right Size Tankless Water Heater

Water Tank TipsIt’s time to upgrade to a tankless water heating system. How do you know the right size tankless water heater for your home? It’s not that hard to figure it out. You only need to know two things – the peak hot water usage in your home and the flow rating of the water heater you are looking at purchasing.

Figuring out your peak hot water usage is pretty easy. It usually happens in the morning when people are using the bathroom to get ready for work. You have the shower, the bathroom faucet and whatever water usage is going on in the kitchen and maybe even the laundry room. Add up the shower head gallons per minute (gpm), which is 2.5, the faucets you will be using with hot water (0.5 gpm each), the dishwasher (3 gpm) and the washing machine (3 gpm). Your totals will be between 3 and 9 gpm.

Next, determine the temperature rise that you will need for your home. Most city water comes into the home at between 50 and 60 degrees. You’ll probably want 120 degrees at the tap. This puts temperature rise between 60 and 70 degrees. This will be one of the temperature ratings for gpm on most units. Gas units can reliably deliver about 5 gpm at this temperature rise, while electric units can produce about 2 gpm.

If your peak hot water usage is above 5 gpm, you have two choices. You can install a multi-unit tankless water heating system or you can adjust your water usage. Remember, hot water will be delivered to the taps closest to the water heater first, so any loss of temperature will be noticed at the taps furthest from the heater.

We know you have questions about tankless water heating. That’s why we’re here. For more expert advice getting the right size tankless water heater for your family’s needs, contact us at Aggressive Mechanical Contractors. We have been proudly serving Monmouth County, N.J. and surrounding areas since 1948.

Our goal is to help educate our customers in Monmouth County, New Jersey and surrounding areas about energy and home comfort issues (specific to HVAC systems). For more information about tankless water heaters and other HVAC topics, download our free Home Comfort Resource guide.

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