How to Choose the Correct Size Water Heater
What should you consider
- The first thing that you should consider is how many people live in your home.
- Second and the most important is your home’s highest one hour demand period. This is when the highest demand for hot water will be. Some families take several showers, one right after the other, either in the morning or at night. An average shower uses 20 gallons of hot water.
Traditional hot water size calculator
The regular rule of thumb is one person household needs a 25 gallon. A two person household should choose a 35 gallon. A three person household should choose a 45 gallon. A five person household should choose a 55 gallon and a six person household should choose a 65 gallon water heater.
What is a hot water demand period or hour
For example we will use a family of four. This family has one parent showering before work at around 7:00 am and a teenager also getting up and taking a shower before school before 7:00 am.
The mother usually takes a bath before bed at 9:30 pm and bathes their youngest at 8:00 pm. and the other major hot water uses are washing clothes, which happens throughout the weekend and uses about 20 gallons for each load. Brushing teeth in the morning and before bedtime, which will use half a gallon of water each and washing hands which uses about three gallons on average.
Our recommendation for the family above
Now to truly get the best size water heater let’s do a little math. If we use the top two bullet points and calculate the high demand hour, you will get the perfect sized water heater. There are two periods of an hour that use 40 gallons for showers, baths and then you need to include brushing teeth, washing hands and shaving.