The water heating system is one of the most important parts of a home. It operates in the background of our home and it keeps our hot water flowing. When it’s working, we almost never notice it. We should be giving thanks every time we have a warm shower, do the dishes, or use hot water in any other way. Because we’re mostly accustomed to having the hot water we need when we need it, we might not even think about our hot water heater until something goes wrong with it.
When we look at how our water heating system works, one of the key aspects of understanding the system involves learning how to size a hot water heater. Whether you’re building a new home or renovating an existing one, you will want to know what size water heater you’ll need.
Pursuant to that, we’re going to help you by teaching you some of the key elements of the hot water heater sizing process. We’ll explain some of the details surrounding tank size, how to estimate your usage, the first-hour rating, and more.
After that, we’ll explain some of the specifics of tankless options, and how to determine if they’re a good fit for you or not.
One thing that we would strongly recommend is getting in touch with professionals for your hot water heater installation. This is most likely not a task you would want to do yourself, as some of the worst home DIY disasters have to do with water. American Home Water & Air are experts when it comes to installing hot water heaters, and can help you choose the best fit for you, based on your budget and requirements.
Water Heater Tank Size
The first thing you should be looking at if you’re considering buying a new water heater is tank size. Tank size refers to the amount of water that a hot water heater can store. The tank capacity is usually given in gallons.
Estimating by residents
To effectively begin your estimation, you can start by simply counting the number of residents. If you have 2 residents regularly using the hot water, you can expect you need a water heater with a capacity of around 30 gallons. 2-4 users means you would want around 50 gallons of capacity, and 3-5 people would need closer to 60 gallons. If you have more than 5 people, just keep adding ~10 gallons to the total.
This should give you a basic understanding of your hot water requirements, but there are some further steps you should consider. Next, we’re going to talk about the most misunderstood way in which hot water heaters are measured.
First Hour Rating
The First Hour Rating is one of the most important factors you need to understand if you’re trying to figure out how to size a water heater. In simple terms, the first hour rating refers to the amount of hot water your heater can produce in one hour. This is important because hot water heaters might not work the way they’re commonly perceived to work.
Many people think that a hot water heater fills its tank up, then heats the water for you to use. But the truth is slightly different. Really, when the water in the tank is heated and then used, your heater gets to work right away making more hot water. The first hour rating helps us to understand how quickly the hot water heater makes more hot water. The first hour rating refers specifically to the amount of hot water that can be produced in one hour.
You should be looking for a hot water heater that has a first hour rating equal to or greater than the amount of water required for your busiest hour of hot water usage.
Hot Water Habits
To understand your hot water usage, you should try to come up with a calculation of the average amount of hot water you’re using in a day. For example, a bath could take 15-25 gallons, whereas running your washing machine might take around 30 gallons of hot water. When you consider the maximum usage, you can start to get an idea of how much available hot water you’ll need.
To help lower this number, you can start by considering some hot water habits. You don’t want to be showering, running your dishwasher, and washing your clothes all at once. The more effectively you split up those tasks throughout the day, the better your hot water heater will operate.
If you have a busy household or a tight schedule, you might want to look at a hot water heater with a bigger tank, and a higher first hour rating.
One possible solution is to look at a tankless hot water heater. Tankless water heaters are exactly what they sound like. They’re water heaters that don’t have a tank! Instead, they only heat water as it’s needed. A tankless water heater has more to do with the first hour rating we were talking about earlier than with storage capacity.