How to Choose the Right-Sized Tankless Water Heater for Your Home

Looking to install a new tankless water heater in your home? The market’s range of options can seem overwhelming. But worry not, this detailed guide is here to walk you through the process.

Tankless water heaters, also known as demand-type or instantaneous water heaters, have become increasingly popular due to their efficiency and endless supply of hot water. However, choosing the right size is critical for performance and longevity.

How Does a Tankless Water Heater Work?

Before delving into how to choose the right size, it’s important to understand how these little marvels work. Unlike traditional water heaters that store heated water in a tank, tankless water heaters heat water directly without the use of storage. When a hot water tap is turned on, cold water travels through a pipe into the unit, where either a gas burner or an electric element heats the water.

Why Choosing the Right Size Matters

Choosing an undersized heater can lead to hot water shortages, while an oversized one leads to wastage and unnecessary costs. Here’s what you need to consider to choose the right-sized tankless water heater:

Understanding Flow Rate and Temperature Rise

Flow Rate

Flow rate is the amount of water a tankless water heater can heat at a time, measured in gallons per minute (GPM). Major household applications like showers, washing machines, and dishwashers have different GPM specifications.

Determining the Required Flow Rate

To calculate your home’s required flow rate, you need to estimate the number of devices you’d run concurrently and their total GPM. For instance, if you expect to run a shower (2.5 GPM) and a washing machine (2 GPM) at the same time, you’d need a unit with at least 4.5 GPM.

Temperature Rise

Temperature rise refers to the increase in water temperature achieved by a heater. It’s determined by the inlet water temperature and desired output temperature. A typical desired output is 120°F. If the incoming water is 50°F, the temperature rise is 70°F.

Calculating Temperature Rise

Consider the coldest month in your region to calculate temperature rise. You can seek professional help or use online resources that provide average groundwater temperatures.

Types of Tankless Water Heaters

There are two main types of tankless water heaters: electric and gas-fueled. Electric versions are highly efficient and demand lower upfront installation costs but can’t heat large volumes. Gas heaters, on the other hand, are ideal when high flow rates are needed, despite their higher installation costs.

Electric Tankless Water Heaters

Pros and Cons of Electric Models

Electric models are more energy-efficient, easier to install, and require less maintenance. However, they tend to have a lower flow rate.

Gas-Fueled Tankless Water Heaters

Pros and Cons of Gas Models

Gas versions offer higher flow rates and work even during power outages but are costlier and require venting.

Choosing the Right Size for Your Home

Small House or Apartment

For a small house or apartment with one or two residents, an electric tankless heater will often suffice due to the lower water demand.

Medium to Large House

For larger homes with more than two people and possibly multiple bathrooms, a gas-fueled model is recommended to handle the higher flow rate.

Ensure endless hot water with the right-sized tankless heater

Explore our guide on selecting the right size for your needs and enjoy continuous, efficient hot water.
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In Summary

A tankless water heater can provide continuous hot water while reducing energy costs and saving space. However, it’s vital to choose the right size for your needs, which depends heavily on flow rate, temperature rise, and the type of heater suited for your home.

Consider Professional Advice

For accurate assessments, consider professional advice. A professional can factor in all elements, ensuring you pick the optimal sized tankless water heater.

Always Remember

In the end, remember that an optimally sized tankless water heater optimizes both energy use and performance. Take time to research, evaluate your needs, consult if need be, and make an informed decision. Because a warmer, more energy-efficient home awaits.