When in the market for new Water heaters in Minnesota, most homeowners are only concerned with capacity. You may be surprised to know that buying a larger tank may not provide you with enough hot water. The First Hour Rating (FHR) is equally important, and is something you should definitely consider before making a purchase.
What is the First Hour Rating?
Put simply, the First Hour Rating lets you know how much hot water the heater will produce in a given amount of time. It generally refers to the amount of hot water your tank can provide during a period of heavy use-typically the first hour of the day when demand is especially high. For example, an 80-gallon tank may have a FHR of 56, meaning it can provide that many gallons of hot water during the first hour, leaving the remaining 24 gallons stored in the tank ready to be heated.
The First Hour Rating is listed on your tank’s yellow label along with its energy information. It is calculated using the following formula: Tank Capacity x .70 + Recovery (gallons per hour at an 80 degree rise in temperature).
Gas and Oil vs. Electric
Gas and oil models tend to have higher FHRs than electric models. This is because their flames tend to heat water more quickly than the elements found on electric units. That doesn’t mean you can’t get by with an electric water heater, but it does mean you could need a larger unit if you have extremely high usage during certain parts of the day.
Determining the size and type of water heater you need, as well as its FHR can be challenging for some. If you are having a hard time choosing the right model to fit your needs, please contact us.