When it’s time to replace the water heater in your Clearwater, FL, home, make sure you do some calculations so you can purchase the right size. This doesn’t just mean the ideal size for today, either, as water heaters typically last eight to 15+ years. Instead, you’ll want to give some thought to whether your family size will be growing during the next 15 years. That way, you won’t find yourself constantly running out of hot water down the line.
What Size Water Heater is Best for Me?
If you’re planning to get a typical tank-style heater, the following list can make your life much easier.
- One to two people – 23 to 36 gallons
- Two to four people – 36 to 46 gallons
- Three to five people – 46 to 56 gallons
- Five or more people – 56+ gallons (add 10 gallons per extra person)
Most families of four can get away with using a 40-gallon water heater. Of course, this doesn’t mean that you should just purchase a 40-gallon water heater for your family. It’s important to carefully consider your family’s first hour rating (FHR) as well.
What is a First Hour Rating?
The FHR of a water heater indicates how much hot water your heated device can provide in a single hour. FHR should be based on peak hour usage. The higher the FHR, the more efficient your hot water will be. The FHR you select needs to provide more hot water than your family uses during peak times. Consider the following list when you’re attempting to calculate your needs.
- Showering or bathing – 20 gallons per person
- Washing hair – 6 gallons per person
- Shaving – 3 gallons per person
- Washing hands – 2 gallons per person
- Running the washing machine – 30 gallons
- Running the dishwasher – 14 gallons
- Washing dishes by hand – 6 gallons
Let’s assume you have a family of four. Two of you bathe and wash your hair in an hour. Plus, one of you shaves, four of you wash your hands, and you usually run the washing machine too. Your FHR would be 91, so it’s a good idea to find a water heater with an FHR of no less than 95. When investigating your options, ensure you don’t confuse your FHR with the number of gallons you’ll need.
Should I Invest in a Tankless Heater Instead?
One major benefit of selecting a tankless water heater is that it doesn’t require nearly as much space. To give you an idea of how much smaller a tankless heater is, consider the following:
- 50-gallon storage tank – 72 inches high, 22 inches in diameter
- 50-gallon tankless heater – 20 inches high, 14 inches wide and 10 inches deep
As you can see, a tankless option is vastly superior for those who don’t have enough space. However, choosing one of these water heaters requires you to figure out the unit’s flow rate, rather than its FHR.
How to Calculate Flow Rate
Calculate your peak usage by using the following gallons per minute list:
- Bathtub – 3 GPM
- Washing machine – 3 GPM
- Dishwasher – 3 GPM
- Shower – 2.5 GPM
- Sink faucet – 1 GPM
Using the same family of four assumptions listed above, let’s say that both people take a 10-minute shower. The person who shaves takes five minutes. Washing hands takes one minute per person, and your washing machine cycle is 45 minutes. To meet everyone’s needs for the hour, you’d need 194 gallons or 14 GPM. You’re not quite done yet, though.
Next Step: Temperature Rise
The next step is to turn on a faucet in the cold position. Wait a couple of minutes, then use a thermometer to see how cold it is. For the purposes of this article, we’ll assume that your cold water is 60 degrees. Subtract this number from the average high temperature of 110 degrees, and you’ll end up with 50. Look at each tankless water heater’s required temperature rise chart, and you’ll find out exactly what your flow rate should be!
Expert Plumbers in Clearwater
Whether the calculations above make perfect sense or leave you feeling confused, Benjamin Franklin Plumbing is here to help. Our professional team of plumbers provide water heater installation and tankless water heater installation services. Additionally, we can handle any of your Clearwater home’s needs, ranging from hydro jetting and shower repairs to well pump repairs.
Are you in the market for a new water heater? Reach out to Clearwater’s expert team today at Benjamin Franklin Plumbing!