Getting the right water heater for your home is important, just like choosing the right-sized furniture or kitchen appliances. If a water heater is too small, you’ll have to deal with cold showers and not having enough hot water for daily needs. Too big, and you’ll be paying more than necessary on your energy bills.
Let’s go over everything you need to know about sizing a new water heater. By the end, you’ll feel more confident about how to choose the right size water heater for your household’s unique needs.
Why Getting the Right Size Water Heater Matters
Before we can review how to choose the right size water heater, you should know why this consideration is necessary. Selecting the appropriate size water heater can considerably impact your daily comfort, energy bills, and even your appliance’s lifespan. A properly sized water heater keeps up with your family’s peak hot water usage, whether it’s during morning showers or evening dishwashing. Choosing the wrong size could lead to endless cycles of reheating water, higher energy bills, and less hot water when you need it most.
So, how do you find the sweet spot? Let’s go over what you need to know about sizing a new water heater, understanding your household’s demand, and picking the right type for optimal performance.
Types of Water Heaters and How They Impact Sizing
Want to learn how to size your water heater? Then, it’s helpful to know what options you have. Each type has its own requirements, so understanding these will guide you toward the best choice. Let’s discuss two of the most common types of water heaters.
Conventional Storage Water Heaters
These are the most common types found in homes and come with a storage tank that keeps hot water on reserve. Sizing a new water heater of this type requires knowing your household’s peak hot water usage, typically measured in gallons per hour.
Tankless Water Heaters
Tankless water heaters heat water directly without a storage tank. This type is efficient, as it heats water only when needed. When choosing tankless water heater sizing, consider both the flow rate and temperature rise needed to meet your household’s peak hot water demand.
How to Choose the Right Size Water Heater for Your Home
When sizing a new water heater, a few calculations can help you find the best option for your home. Here’s a step-by-step approach to help you choose the right size water heater.
Step 1: Estimate Peak Hour Demand
The first thing to consider is your home’s peak hour demand — how much hot water you need during the busiest one-hour period. Think about how many gallons of hot water are used for showers, dishwashing, and laundry during that time. For example, a ten-minute shower might use about ten gallons of hot water, and a load of laundry could use 25 gallons.
Step 2: Determine the Temperature Rise
Temperature rise is the difference between the cold water’s temperature as it enters your home and the temperature you want for hot water. Typically, incoming water is about 50°F, and most people prefer their hot water to be around 120°F, meaning a temperature rise of 70°F. Your water heater will need to work hard to reach this higher temperature.
Step 3: Check the First Hour Rating (FHR) for Storage Heaters
If you’re looking at a conventional storage water heater, check its first hour rating (FHR). This number tells you how many gallons of hot water the heater can produce in an hour when fully heated. Try to match this number as closely as possible to your peak hour demand to guarantee you have enough hot water.
Alternative Step 3: Calculate the Flow Rate for Tankless Heaters
For tankless water heaters, sizing is based on flow rate (measured in gallons per minute or GPM) instead of storage. If you have high water usage or need hot water at multiple locations at once, you’ll want a tankless unit that can handle the combined flow rate.
Key Factors to Consider When Sizing a Water Heater
Several other factors can influence your water heater size. Let’s go over the most important ones to keep in mind.
Household Size and Usage Patterns
Larger households or homes with lots of hot water use will need a bigger water heater to meet demand. Also, consider when your household typically uses hot water. If most hot water use happens in the morning, this could impact the size of the heater you need.
Fuel Type
Water heaters can be powered by electricity, natural gas, propane, or even solar energy. Gas water heaters generally heat water faster than electric models, so if you have a gas water heater, you may need a slightly smaller size compared to an electric one.
Climate and Incoming Water Temperature
Homes in colder regions may need a larger water heater because the colder incoming water requires a higher temperature rise. Heat pump water heaters can also be affected by temperature, performing best in warmer environments.
Energy Efficiency Preferences
For those looking to save on energy costs, high-efficiency models, such as ENERGY STAR-certified water heaters, are a great choice. Though they may cost more upfront, they often result in long-term savings. Options like tankless water heaters and heat pumps are especially efficient.
Practical Steps for Sizing a New Water Heater
If you’re not sure where to begin, here’s a step-by-step checklist:
- Estimate Household Demand: Count the peak hour demand based on family size and water usage habits.
- Choose Type: Decide between tank or tankless models based on space, lifestyle, and efficiency needs.
- Calculate Flow Rate/First Hour Rating: Use your demand estimates to find the right FHR for tank heaters or flow rate for tankless models.
- Consult a Professional: If you’re still unsure about what size water heater you need, a consultation with a local expert can simplify the process.
Need a New Water Heater in Tulsa, OK? Call Us Today!
Are you still asking yourself, “What size water heater do I need?” At Williams Plumbing & Drain, our Tulsa plumbers are ready to help you find the best fit. We’ll walk you through your options, answer questions about how to choose the right size water heater, and take care of the installation so you never have to worry about cold showers or high energy bills again.
Contact us today for your water heater installation in Tulsa, OK, or one of the surrounding areas! Our team is here to make sure your water heater is just the right size.