What Size Water Meter Do I Need

Adequately sizing a h2o heater is non all that easy. When choosing a h2o heater capacity for a family unit of 2, 3, iv, 5, or 6, there are two rather common mistakes nearly people brand:

Getting a besides small-scale water heater (undersizing). If your water heater chapters is too low, you are likely to run out of hot water while showering. Example of a as well minor water heater: Installing a 30-gallon water heater for a family of 5. That'due south more than 50% of the water heater chapters that you actually need.
Getting a too big water heater (oversizing). If the water heater capacity surpasses your hot water needs, you lot have unnecessarily higher water heater costs. Example of a likewise big water heater: Installing a 60-gallon h2o heater for a family of 2. That'due south at about twenty-gallons more than you need, and you accept needlessly spent $150 additional dollars on the heater, and wasted space.

Both of these mistakes tin exist avoided if you know how to properly choose a water heater capacity for your hot water needs.

Hither's the affair:

You only have 1 shot at sizing your water heater. You lot don't want to blow it and buy a unit that'southward either too big or besides pocket-sized.

That's we volition wait into how to pick the correct water heater size for your dwelling house. That includes factors that increase/decrease the water heater capacity requirements (size of your family, hot water needs, etc.). We include the full general rule of thumb for sizing whatsoever water heater (it's fairly piece of cake to employ, just you need to estimate your peak hour hot water need properly).

On elevation of that, we simplified water heater sizing with a 'Water Heater Sizing Computer' . You just input the size of your family, hot water needs, and the calculator will give yous a rough gauge of how big a water heater you need, based on boilerplate hot water consumption. Here'south how the results look similar (screenshot):

hot water heater capacity calculator — You can find this 'Water Heater Sizing Reckoner' further on. Only input family size and relative hot water needs, and you volition get a rough judge of how big a hot water heater you need.

Let's beginning familiarize ourselves with water heater sizing concepts similar 'first hour rating', 'h2o heater chapters', and 'peak hour hot water demand'. With this knowledge, you will easily understand the prepared table with h2o heater sizes for a family of one, ii, 3, 4, 5, and 6:

How To Approximate The Size Of A H2o Heater Yous Demand?

The cardinal spec that helps us adequately size a water heater is the h2o heater chapters rating.

We talk about 30-gallon, 40-gallon, 50-gallon, sixty-gallon water heaters. That number of gallons is the 'water heater chapters rating'. This is also known as 'outset hour rating'. It is a volumetric corporeality of hot h2o a heater can provide within the first hr, starting with a tank full of hot water.

How to observe what the start hour rating is?

Unproblematic. The FTC (Federal Trade Commission) rule is that every conventional storage water heater producer has to include this rating on the EnergyGuide label. Just check the label, and you volition observe out how big your water heater actually is.

Hither is the rule of thumb for h2o heater sizing:

First 60 minutes Rating (Heater Chapters) ≤ Peak Hour Demand (Usually 1 hour when we shower)

That means that your water heater should be at least big enough to meet the most demanding 1-60 minutes hot water demands your household has.

Example: From ten PM to eleven PM three people have a shower. In i shower we use 20 gallons of hot water (according to United states Energy Saver). That means that yous will demand a 60-gallon water heater or bigger.

As we volition come across further on, the exact size of a water heater depends on your hot water needs. That roughly translates into how large a family unit yous take. Example: A family of v volition spend less hot water than a family of 3.

After that kickoff hr (we started with a tank total of hot water), the hot water output of a water heater depends on three primary factors. These are:

Water heater tank capacity.
Heat source (gas vs electricity); this tin exist either burner (gas water heater with tank) or chemical element (electric water heater with tank). We talk nigh electrical water heaters
Size of the said rut source; namely, how big a burner or how large an element you take.

Obviously, any water heater will be able to produce less hot water in the 2nd, third, etc., hour after the 1st hour.

Example: If you have a 50-gallon water heater (first hour rating is 50 gallons), you will get fifty-gallons of water heater for the 1st 60 minutes. However, in the 2nd 60 minutes, you volition likely get much less than l gallons of hot water (nigh 16 gallons on average in this case).

If we want to follow the above rule of thumb for sizing a water heater, we demand to assess how much hot water we demand during our showering peak 60 minutes. Hither's a lilliputian help to do just that:

Estimating Meridian 60 minutes Need: This Is The Fundamental Stride

It'southward fairly unproblematic to size a water heater in theory (using the dominion of pollex). Just add together upwardly all the hot water you require in the nigh intense hot water hour. That's usually the hr when a large part of the whole household showers.

The size of a h2o heater should match that capacity, and you can add some gallons on top of that.

Now, the key step is to adequately estimate the peak 60 minutes hot water need. That means that yous have to add up all the hot water you utilise in that hr, including showering, washing teeth, hand washing, shaving, dishwashers, and so on.

To assist you lot out, nosotros specific some of the most common activities that crave hot h2o with the hot h2o needs here:

Showering: 20-gallons per shower.
Washing teeth: 0.5 gallons.
Hand washing: 3 gallons.
Shaving: 2 gallons.
Top-loader clothes washer: 25 gallons.
H-Axis clothes washer: 15 gallons.

Here is an example of how you can estimate the peak hot 60 minutes needs in practice. Permit's say that you have a 4 family household with two bathrooms. From 10 PM to xi PM iii people have a shower, i person is shaving, and all iv family members launder their teeth.

The accumulated hot water needs are:

iii×xx gallons (3 showers) + i×2 gallons (shaving) + 4×0.5 gallons (washing teeth) = 64 gallons

This means that you need a water heater with at to the lowest degree a 64-gallon capacity. You tin hands get a 70-gallon water heater in this case but a sixty-gallon water heater will likely exist besides minor (undersized). An 80-gallon h2o heater for a family of 4 is more often than not too big.

If you determine your hot water needs using this 'pinnacle 60 minutes demand' rule of thumb, you accept a flake of wiggle infinite in the upper management. Y'all tin add about 10% to fifteen% to the calculated water heater capacity. That means that you can get a 70-gallon water heater if y'all calculate the elevation hour hot h2o demand to exist 64 gallons.

However, you should not choose a smaller water heater capacity. In exercise, if you calculated you accept 64 gallons height hr hot water needs, you should cull a 64-gallon water heater or bigger. Never smaller.

Notation: Undersizing a water heater will be more problematic than oversizing a water heater.

If all this seems a flake complex, don't worry.

There is an easier way to size a water heater. Information technology's based on iii principles:

Size of the family.
Average use of hot water per person per hr. Co-ordinate to Technology Toolbox, an average person consumes 10 gallons of hot water per hour. We talk about the peak hr demand, of course.
Baseline of fifteen-to-xx gallons of water per household. Every household has some basic hot water needs, contained of how many people alive in the house.

Based on these 3 principles, we can roughly guess what size water heater you need given how big a family unit you take:

Water Heater Sizing Figurer (Based On Family unit Size)

This is a 'What Size Water Heater Do I Need' estimator that volition requite you a rough estimate of how big a h2o heater you need. You lot but input your family size and hot h2o requirements (beneath-average, boilerplate, or to a higher place average), and the water heater size calculator will dynamically make up one's mind the water heater capacity in gallons:

Based on this water heater sizing method, you can roughly see what size water heater you need for your family:

Family Size	Water Heater Size (Gallons)
Family of 1	25 Gallons
Family of 2	35 Gallons
Family of three	45 Gallons
Family of four	55 Gallons
Family of 5	65 Gallons
Family unit of 6	75 Gallons

Note of buying a water heater: Check for the Energy Star characterization as well. Free energy-efficient water heaters in most cases pay off. You tin can read more about the requirements for an Energy Star label hither.

We hope all of this was helpful.