How to Size a Water Heater | Expert Tips

The last thing that most people want to do is purchase a hot water heater that is too large or too small for their needs. Sizing a residential water heater will depend on many factors. Among them are the energy costs, usage, a size of the home and the type of water heater that is purchased. A look at some of the aspects of choosing the right type and model is outlined below.

When deciding on the proper size water heater, one of the main concerns is the cost of operating the unit. Of course, everyone wants the best size water heater that will save money in the long run. The best way of calculating the expenses of a water heater is to look for the energy factor of the unit you are considering. When this is used in combination with the first-hour rating (FHR), choosing a water heater that does not contribute to wasted energy is easier.How to Size a Water Heater

How to Size a Water Heater

The FHR was a number that was created by the National Appliance Energy Conservation Act. The number was originally used as a guideline for contractors. To arrive at this number, take the number of people in the household plus one and multiply this by 12. The 12 is the number of gallons of water used per person. If there are four people in the household, multiply 12 times 5 and the FHR is 60.

Once you have this number, look for water heaters with this first hour rating. This is generally always included in the specifications that can be found on the yellow tag on the water heater. When the FHR needed is found, look for the highest energy rating among these water heaters. The closer the energy rating is to 1, the better the energy savings. This information is on the yellow tag as well.

Remember to take into consideration if there are people in the household who may use more hot water than others. The numbers are based on average shower times, but if your household contains young children or teenagers, this could be higher.water heater bg chart

Hot Water Usage

How much hot water you use is another factor that will determine the size of the water heating appliance needed. The home that uses a lot of hot water consistently will not benefit from a water heater that does not provide the correct amount. Often when people get ready to replace an old water heater, they will buy a larger one. This is not the way to decide on the size, even if the existing model was not providing enough hot water.

The problem may not be the size of the unit, but the amount of hot water that is used. If a household runs several appliances at the same time as showers are being taken, the size of the water heater is not going to make a difference. This is where tankless water heaters come into the picture. There are models that can handle several applications at the same time and provide enough hot water for each one.

Tankless or Tank Water Heaters

After calculating the amount of hot water that your family typically needs, this may indicate a tankless water heater would be a better choice. For households that require a large amount of hot water, a tankless water heater provides hot water on demand. This can save money and running out of hot water in the middle of your shower is not a problem.

On the other hand, a storage or tank water heater can work well. The key is to look at the BTU input or the first hour recovery – not the gallons the water heater holds. Tankless water heaters hold no water, yet they can heat water instantly. Using the first hour recovery numbers along with the other key factors such as the energy efficiency is the best way to choose a tankless water heater as well as a storage tank type.water heater size chart

The Size of the Water Heater

The capacity of the water heater should not be the only consideration when choosing the correct size. For example, a 75,000 BTU, 100-gallon water heater does not provide as much hot water as a 250,000 BTU, 65-gallon water heater. The combination of how much water a tank holds plus how much it can heat in one hour should be the consideration.

The combination of how much water a tank holds plus how much it can heat in one hour should be the consideration. Additionally, buying a water heater that is too large for your needs wastes money. The water is being heated, reheated, and not used.

While it may be a comforting thought to know you have 100 gallons of hot water sitting in the tank, reheating this water repeatedly is wasted energy. So, while you may be tempted to think that bigger is the way to go, this is not always necessarily true. Read Best Reviews on WaterHeaterReviewer