What size water heater do i need

What size water heater do i need

What size water heater do I need? What size water heater will work for me? There are a lot of questions that arise in people looking to replace or install a brand new water heater. In this guide, we will cover what different sizing homes use, and go into further detail about what it takes to figure out just how big you really need your water heater to be.

As if the first step in finding the right water heater isn’t hard enough, there are so many different sizes available now that it can be a bit overwhelming. Sure you know about the standard American size of 40, 50, and 60 gallons per hour, but that just covers three of them. There are numerous other sizes and configurations available to fit your household size and daily hot water needs. But which one is right for you? There’s only one way to find out…keep on reading.

What is Water Heater

A water heater is a system used to heat water for use in household plumbing fixtures, places of business, or for other purposes. It may include an electric heating element and elements made of indirect thermal technology or gas heaters fueled by natural gas, propane, heating oil, or other energy sources. 

A typical modern water heater will have four major parts: the tank, the circulator, the pump, and the faucet. A tankless water heater has no built-in tank. Instead, it uses an external source of hot water such as a city supply line or solar hot water collector.

Water Heater Sizes

The size of your home’s water tank is one of the most important factors in determining what size water heater you will need. If you plan to have a home water heater for many years, it may be worth investing in a larger model. However, if you are only planning on needing a heater for a few years, then it may be worth purchasing one that is smaller. 

What size water heater do i need

To help determine what size water heater you should purchase, there are several factors you should consider. You should also check with your local plumbing or heating contractor to make sure that they can install a certain sized tank and not void your warranty by doing so. Getting the hot water capacity right can be confusing. Therefore, we do advise that you start by figuring out how many people will be using hot water at one time.  

In the market, you will find multiple water heaters available in different sizes. To select which water heater you need first you need to determine the average water usage per day. To select a water heater, keep these things in mind :

    1. Fuel Source of the Water Heater: You must decide which fuel source you use for your water heater like electricity, liquid propane, natural gas. This will make it easier to make a choice that is good for you.
    2. Space required by Water Heater: You also need to consider that the water heater you are selecting could easily fit in your allotted space or not.
    3. Family size: This is also very important to determine how many persons are in your home based on which you can easily determine the water usage which helps in selecting the appropriate size of the water heater.

How much hot water do you need?

The size of your household’s water heater has little to do with how much hot water you use. The amount of hot water used in your home is primarily driven by how much water you actually fill the vessel with. So, if you have a faucet that supplies two people with five gallons per minute (GPM), but only ever fills the tub halfway, then you’re using 50 percent less hot water than the GPM indicates. Ambient temperature and guest load also factor into an individual family’s water heater use habits.

What size water heater do i need

You’ll want to make sure that the size of your water heater is adequate for the number and size of people in your household and the number of showers you take per day. Just as estimated, a 60-gallon water heater could be used for a family of four with two adults taking three or more daily hot showers. 

You should also consider how often you run your hot water faucet for washing dishes, preparing meals, and brewing coffee throughout the day. A large family or person who takes very long showers will need a larger water heater than one who takes only brief showers.

To learn what size water heater is best for your household, you need to first determine how much hot water your family uses. This is because some things, such as hand washing, can cause a great deal of hot water use while others, such as quick loads of dishes or automatic dishwashers, cause little to no hot water use. Knowing your usage patterns and how much you plan on using hot water will help you determine what size water heater is right for you.

Other factors to size your water heater

When sizing a new water heater, pay particular attention to the room size and how much hot water your home will use on a daily basis. A good rule of thumb is to divide the total amount of cubic feet of space being heated by the total number of gallons of water used daily. 

The result is the number of gallons per hour your water heater must be able to produce in order to efficiently meet your home’s daily demand for hot water. Additionally, most homes today have at least three people living in them; however, only one person uses nearly all of the hot water simultaneously during morning showers and bathroom preparations for everyone else.

What size water heater do i need

What size water heater do I need

Water Heater with Tank

If you want to purchase a water heater with a storage tank, here is the approximate size of water heater required with a number of family members in your home :

  • You need to purchase a water heater with a tank capacity of around 30-gallons for a family of 1-2 people.
  • You need to purchase a water heater with a tank capacity of around 40-gallons for a family of 2-3 people.
  • For 3-4 people, there is a requirement of a water heater with a 40-gallons tank capacity if it runs over liquid propane or natural gas. If the water heater runs on electricity (you can check here if you want to know how much electricity is consumed by the electric water heater), then you must purchase a water heater with a tank capacity of 50-gallons.
  • For a family size 5 or more than this, you need a water heater with a tank capacity of at least 50-gallons if you want to use fuel like propane or natural gas. For a water heater that runs on electricity, the tank capacity required is at least 80-gallons.

What size water heater do i need

Tankless Water Heater

Here is the approximate water heater flow rate for a tankless water heater system based on the number of appliances you have attached with the water heater to use at the same time. Here we are considering the groundwater temperature is 50 degrees Fahrenheit. If your desired water temperature is 100 degrees Fahrenheit then in that case a 50-degree temperature rise tankless water heater system is recommended.

  • You should install a water heater system of flow rate 3.5 GPM for using 1-2 appliances at a time.
  • For 2-3 appliances at a time, the water heater flow rate must be at least 5 GPM or more than this.
  • If you want to use 3-4 appliances at a time you require a water heater with a flow rate of 7 GPM.
  • If someone wants to use 5 or more appliances at a time then there is a need to install multiple tankless water heaters in series

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