How To Determine Water Heater Size Needed

Great question.

The respond? Well, to go an authentic respond y'all'd accept to calculate out how much hot water you typically utilise during your busiest "hot-water-using" hour.

Merely if y'all only need a loose estimate of what size you lot demand (versus an exact calculation), follow these guidelines:

For one to ii people: 30-40 gallons
For two to three people: 40-50 gallons
For three to four people: 50-lx gallons
For 5+ people: 60-lxxx gallons

We'll explain why the numbers above are simply "loose estimates" and how they might non accurately meet your hot water needs. We'll too bear witness you lot how to calculate the exact h2o heater size that meets your needs (and saves you money).

Heads upward: this article volition focus on tank water heater sizing. If you're interested in a tankless water heater and need sizing advice, just check out our blog on tankless water heater sizing .

Want a plumber to professionally size and install a water heater that's perfect for your home? Just contact united states of america and nosotros'll handle it all for you.

Only need a loose estimate for now? Start here…

Sometimes, homeowners only want a vague idea of water heater sizing and so that they can go a better idea of how much their water heater install will cost. (Spoiler alert: the size of your water heater directly relates to its cost; the "bigger" the h2o heater, the college the cost.)

In that case, y'all can gauge the size you lot'd need based on the number of people in your household (see beneath).

Warning: The numbers in this nautical chart are to be used as very full general guidelines and may non accurately match your hot water needs.

For case, a family of 5 or more than could live very comfortably on a 30-gallon tank h2o heater while a household of two might notice that a 30-gallon tank tin can't provide enough hot water for their needs.

You encounter, the size you need completely depends on your hot water using habits. If you regularly use iii or more hot water appliances within the same hour, you might demand a much larger tank than the nautical chart higher up indicates. But if you lot rarely use more than one hot water apparatus in the same hour, you might need a much smaller tank.

That said, before you buy a water heater, you should be very certain that the tank size is accurate for you lot.

Hither's why:

A water heater that's too small could lead to never having enough hot water and/or a h2o heater that'south overworked, leading to frequent repairs or premature breakdown.
A h2o heater that's also big could lead to higher-than-necessary free energy bills (to heat water you don't even use).

Set up to acquire the exact water heater size you lot need? Read on…

Want to know the exact size h2o heater you demand? Practise this...

1. Determine which hour during a typical day is your busiest "hot-water-using-hour".

To summate the exact h2o heater size your household needs, you need to offset calculate your "elevation hour demand".

Peak hour demand refers to the maximum amount of hot water you need (measured in gallons) during the busiest hour of your typical day.

Continue in listen that showers typically use the most hot water of all hot water activities/appliances. That existence said, if everyone in your household typically showers in the morning your "summit hour" is most likely during this fourth dimension.

2. Use the chart below to add up the gallons of hot h2o you need during this hour.

Once you've adamant which hour is your peak hour, think of all the hot water activities y'all would normally fit into that specific hour.

Then, use the nautical chart below to calculate your approximate acme 60 minutes need:

Source

iii. Find a water heater that has a "first hour rating" inside 1-2 gallons of your peak hour demand.

All water heaters have an FHR (commencement hour rating). This number signifies the number of gallons of hot h2o the unit tin provide in a single hour, starting with a total tank of hot water.

So, basically, if your FHR and peak hr demand match, your h2o heater will encounter your hot water needs.

If y'all're on a manufacturer's site, you lot can find a water heater'south FHR either under the "specifications", "features" or "performance" section (come across below).

Source

If you're looking on the h2o heater tank itself, you can detect the FHR listed in the superlative left corner of the EnergyGuide label. Information technology will be listed as the "Chapters (first hour rating)".

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Need help from a Florida plumber?

Just contact us. Nosotros offer free estimates where we volition calculate the exact tank size you need.

We've provided quality water heater installations in Florida for over l years—all of which are backed by our 100% satisfaction guarantee! View our Florida service area.