How To Size A Water Heater

Sizing a New Water Heater

A correctly sized water heater will satisfy the hot water requirements of your family while also functioning more effectively. As a result, when choosing a water heater, be certain that it is the appropriate size. These are the guidelines for sizing these systems, which you can find here:

  • Water heaters that are tankless or demand-type
  • Solar water heating systems
  • Storage and heat pump (with tank) water heaters
  • And other options.

Consult a trained contractor for assistance in sizing combined water and space heating systems, which may include certain heat pump systems, as well as tankless coil and indirect water heaters. If you haven’t already decided on the sort of water heater that would be most appropriate for your house, read on to learn more about choosing a new water heater.

Sizing Tankless or Demand-Type Water Heaters

When rating tankless or demand-type water heaters, the greatest temperature rise that may be achieved at a given flow rate is taken into consideration. For this reason, in order to calculate the appropriate size of a demand water heater for your home, you must first estimate the flow rate and temperature increase that will be required for its application (either the entire house or a distant use, such as a bathroom). To begin, make a note of the number of hot water gadgets you anticipate using at any given moment.

  • This is the intended flow rate that you’ll need for the demand water heater that you’ve purchased.
  • You may estimate the flow rate by holding a pan or bucket under the faucet or shower head for a minute and measuring the flow rate that way.
  • (or liters per minute).
  • Installing low-flow water fixtures can help to lower flow rates.
  • Assume that the entering water temperature is 50 degrees Fahrenheit (10 degrees Celsius) unless you know differently.
  • Water should be heated to 120 degrees Fahrenheit (49 degrees Celsius) for the majority of applications.
  • For dishwashers without internal heaters and other similar uses, you may wish to heat your water to 140 degrees Fahrenheit (60 degrees Celsius).
  • When the water temperature reaches 140 degrees Fahrenheit, use caution since it raises the risk of scorching.
  • At a flow rate of 5 gallons per minute through gas-fired demand water heaters and 2 gallons per minute through electric demand water heaters, a temperature rise of 70 degrees Fahrenheit (39 degrees Celsius) is often achieved.

Some tankless water heaters are thermostatically regulated, which means that they may adjust their output temperature based on the amount of water flowing through them and the temperature of the water entering them.

Sizing a Solar Water Heating System

Basic system sizing entails calculating the total collector area and storage capacity required to satisfy 90 percent to 100 percent of your household’s hot water demands throughout the summer. Solar system contractors utilize spreadsheets and computer programs to assist them assess the size of their systems and the number of collectors they need.

Collector Area

Contractors often adhere to a guideline of around 20 square feet (2 square meters) of collector space for each of the first two family members, with the third family member receiving an additional 20 square feet (2 square meters). If you reside in the Sun Belt region of the United States, you should add 8 square feet (0.7 square meters) to your living space for every extra person; if you live in the northern United States, you should add 12–14 square feet.

Storage Volume

A modest storage tank (50- to 60-gallon capacity) is normally suitable for one to two individuals, although a larger tank may be required. It is sufficient for three to four persons to use an 80-gallon storage tank of medium size. A big tank can accommodate four to six people comfortably. Active systems have a solar storage tank that grows in size in proportion to the size of the collector – generally 1.5 gallons per square foot of collector for active systems. When the demand for hot water is minimal, this helps to keep the system from overheating and breaking down.

Other Calculations

Another set of calculations required in estimating your solar water heating system is analyzing the solar resource available on your construction site, as well as establishing the optimal orientation and tilt of the solar collector. For further information on these calculations, please see thesolar water heaterspage.

Sizing Storage and Heat Pump (with Tank) Water Heaters

You should use the water heater’s first hour rating to determine the correct size for your home – this includes heat pump water heaters with tanks. The first hour rating indicates the amount of gallons of hot water that the heater can provide per hour of operation (starting with a tank full of hot water). The tank capacity, heat source (burner or element), and size of the burner or element are all factors to consider. The first hour rating is labeled as “Capacity (first hour rating)” in the upper left corner of the EnergyGuide label, which is displayed on the screen.

The first hour rating may also be found in product literature provided by the manufacturer.

To estimate your peak hour demand, do the following:

  • Determine what time of day (morning, noon, or evening) you use the most hot water in your house and record that information. It’s important to consider the amount of people that will be living in your house. Making an estimate of your maximum hot water use during this one-hour time of the day—also known as your peak hour demand—can be done using the worksheet below. Please keep in mind that the spreadsheet does not estimate total daily hot water use.

The worksheet example displays a total demand of 66 gallons during peak hour usage.

As a result, this home would require a water heater with a first-hour capacity of 66 gallons or greater.

Worksheet for Estimating Peak Hour Demand/First Hour Rating *

Use Average gallons of hot water per usage Times used during 1 hour Gallons used in 1 hour
Shower 20 × =
Shaving (.05 gallon per minute) 2 × =
Hand dishwashing or food prep (2 gallons per minute) 3 × =
Automatic dishwasher 7 × =
Clothes washer × =
– Top-loader 25
– H-Axis 15
Total Peak Hour Demand =
EXAMPLE

3 showers 20 × 3 = 60
1 shave 2 × 1 = 2
1 hand dishwashing 3 × 1 = 3
Peak Hour Demand = 66

*Estimates are based on averages derived from a variety of information published on the internet, including government sources. Various calculators are available on some water heater manufacturer websites, which are depending on the duration of the use case and other criteria.

Solved! How to Select the Right Water Heater Size

Image courtesy of istockphoto.com Q: Our water heater is nearing the end of its useful life. I’ve turned up the temperature on the tank to its highest level, but the water that comes out of the faucet is no longer hot at all. It is therefore necessary to purchase a new water heater. Our present tank has a 30-gallon capacity, which was plenty when we purchased the property ten years ago. However, our family has expanded, and we are now consuming more water for bathing and laundry than before. What type of water heater do I require?

And you’re absolutely correct: Increased people in the family means more water consumption.

“The output is more or less fixed,” he adds.

For a tank-style heater, household size is a simple indicator of hot water needs.

Based on the number of people living in the residence, you may estimate the required tank capacity (in gallons) as follows:

  • For one or two people, 23 to 36 gallons are needed, for two to four people, 36 to 46 gallons are needed, and for three to five people, 46 to 56 gallons are needed
  • For five or more people, more than 56 gallons are needed (add 10 gallons for each extra person).

A 40-gallon water heater, such as A. O. Smith’s ProLine Power Vent Gas Water Heater (available from SupplyHouse), should be sufficient for the average household of four. However, it should not be your only factor to consider. It is possible to obtain a more realistic picture of your family’s hot water requirements by delving a bit further.

In addition to tank capacity, consider a water heater’s first hour rating.

When a tank is fully heated, the first hour rating (FHR) specifies how much hot water it can generate in a single hour when fully heated. At peak consumption, this statistic indicates the appliance’s efficiency (how rapidly the water heater can reheat the water) and provides an indication of how much water it can manage in a given amount of time. A 50-gallon ProLine Power Vent Water Heater (available fromSupplyHouse) has an FHR of 90 gallons, which means it can supply up to 90 gallons of hot water in an hour, as an illustration.

Make use of the statistics in the table below to help you predict peak hour use and establish the best FHR for your situation.

  • Bathing or showering (per person) requires 20 gallons
  • Washing hair (per person) requires 6 gallons
  • Washing hands (per person) requires 2 gallons
  • Washing dishes by hand requires 6 gallons
  • Shaving requires 3 gallons
  • Running the dishwasher requires 14 gallons
  • Running the clothes washer requires 30 gallons.

Consult with a professional Find qualified plumbing professionals in your area and receive free, no-obligation estimates for your plumbing project on HomeAdvisor. +Image courtesy of supplyhouse.com

If a larger tank won’t fit in the existing space, consider a tankless heater.

Tankless heaters, which are often wall-mounted, are able to fit into smaller spaces since they do not require a large storage tank, as O’Brian points out. Typical tank water heaters may be up to six feet tall and 22 inches in diameter, with a capacity of 50 gallons. An alternative tankless water heater with equivalent power, for example, the Takagi Tankless Natural Gas Water Heater (available from SupplyHouse), is just 20 inches high, 14 inches wide, and less than 10 inches deep, making it an ideal choice for small spaces.

If you have a limited amount of available space, a tankless water heater may be the best option. Image courtesy of istockphoto.com

To select the right tankless water heater, estimate the necessary flow rate based on hot water usage and the required change in temperature.

Tankless water heaters do not have a storage tank to hold hot water. Instead, they heat it only when it is required. “Flow rate is the most important factor to consider when sizing a tankless water heater,” O’Brian explains. The following information will assist you in estimating the flow rate requirements for your family.

  1. To begin, figure out how much hot water you use during peak hours. Peak consumption is defined as the period of time during which you consume the largest amount of hot water. In order to compute the maximum amount of hot water you would consume at one time, consider the following list of typical flow rates (per fixture) in gallons-per-minute (gpm)
  • Water flow rates for sink faucet: 1 gpm
  • Bathtub: 3 gpm
  • Shower: 2.5 gpm
  • Dishwasher: 3 gpm
  • Clothes washer: 3 gpm
  1. You’ll need a tankless water heater with a minimum flow rate of 5.5 gpm if, for example, your peak consumption comes after dinner when you’re running the dishwasher and having a shower at the same time (three gallons per minute plus two and a half gallons per minute). Next, find out what the temperature of the water is that is entering your home. Simply turn on a cold water faucet and allow it to flow for a couple of minutes before measuring the temperature of the cold water using a thermometer. To calculate the needed temperature rise, subtract the cold water temperature from 110 degrees Fahrenheit (the typical home hot water temperature) and multiply the result by 100. For example, if the cold water temperature is 65 degrees Fahrenheit, the water heater will need to heat the water 45 degrees Fahrenheit in order to reach 110 degrees Fahrenheit, resulting in a temperature rise of 45 degrees Fahrenheit being required. Increase the flow rate by the amount of temperature rise that is necessary. As O’Brian points out, “all units should be equipped with a chart that depicts the flow of hot water at various temperature increases.” For example, the Takagi T-D2-IN Natural Gas Tankless Water Heater (available fromSupplyHouse) has a maximum flow rate of 10 gpm, with the emphasis on the word “maximum” in the name of clarity. The Takagi has an efficient flow rate of 10 gpm in a warm area where just a temperature increase of 20 degrees is required. Alternatively, if you require the water heater to raise the temperature of the water by 45 degrees Fahrenheit, the flow rate drops to around 7 gpm, as stated on the flow rate chart given by the manufacturer.

Check out this video from SupplyHouse on how to properly size tankless water heaters for a more visual explanation. It is with great pleasure that SupplyHouse.com brings you this article. BobVila.com is the source of the information and viewpoints presented. Consult with a professional Identify qualified plumbing professionals in your area and receive free, no-obligation quotes for your plumbing project.+

What Size Water Heater Do I Need?

That is an excellent question. What is the solution? It is necessary to determine how much hot water you use on a regular basis during your busiest “hot-water-using” hour in order to receive an accurate response. However, if you simply want a rough estimate of the size you require (as opposed to a precise calculation), follow these guidelines:

  • 30-40 gallons for one to two people
  • 40-50 gallons for two to three people
  • 50-60 gallons for three to four people
  • 60-80 gallons for five or more people

We’ll explain why the numbers in the table above are only “rough estimates” and why they may not be precise enough to satisfy your hot water requirements. We’ll also demonstrate how to calculate the precise water heater size that will fulfill your requirements (and saves you money). Please be advised that this essay will focus on the size of tank water heaters. Interested in a tankless water heater but not sure what size to get? Check out our blog on tankless water heater sizes for some guidance.

Simply get in touch with us and we’ll take care of everything.

Only need a loose estimate for now? Start here…

Homeowners may simply require a general understanding of water heater dimensions in order to obtain a better sense of how much their water heater installation will cost in order to budget accordingly. Prediction: the size of your water heater has a direct relationship with the cost of running it; the “larger” your water heater, the more expensive it is to run it. Depending on how many people live in your household, you may estimate the size of the dumpster you’ll need (see below). Please keep in mind that the values in this table are intended to be used as very broad guides only, and they may not exactly reflect your hot water requirements.

See also:  How To Choose A Tankless Electric Water Heater?

As you can see, the size of the tank you require is entirely dependent on your hot water use patterns.

In contrast, if you only seldom use more than one hot water device at the same time, you may only want a considerably smaller tank. That being stated, before purchasing a water heater, you should be certain that the tank capacity is appropriate for your needs. The reason behind this is as follows:

  • Inadequate hot water due to a water heater that is too small may result in never having enough hot water, and/or a water heater that is overworked, resulting in frequent repairs or early collapse. A water heater that is overly large may result in higher-than-necessary energy expenditures (since it is heating water that is not being used)

Are you ready to find out what size water heater you require? Take a look at this.

Want to know the exact size water heater you need? Do this.

To figure out what size water heater your home need, you must first figure out how much water is used during “peak hour demand.” In the context of hot water, peak hour demand refers to the amount of hot water you require (measured in gallons) during the busiest hour of your normal day. Keep in mind that showers, out of all hot water activities/appliances, are the ones that consume the most hot water. That being said, if everyone in your home showers in the mornings on a regular basis, your “peak hour” is most likely to occur around this period.

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

You should consider all of the hot water activities that you would ordinarily fit into that specific hour once you’ve identified which hour is your busiest hour. To determine your approximate peak hour usage for electricity, utilize the chart below. Source

3. Find a water heater that has a “first hour rating” within 1-2 gallons of your peak hour demand.

Every water heater is equipped with an FHR (first hour rating). Using a full tank of hot water as a starting point, this number represents the amount of gallons of hot water the unit can supply in a single hour of operation. So, in general, if your FHR and peak hour demand are in sync, your water heater will provide enough hot water to suit your demands. If you are on a manufacturer’s website, you may discover the FHR of a water heater in the “specifications,” “features,” or “performance” sections of the water heater (see below).

It will be referred to as the “Capacity (first hour rating)” in the report.

Need help from a Florida plumber?

Simply get in touch with us. Upon request, we will provide you with a free estimate in which we will determine the precise tank size you require. We’ve been providing high-quality water heater installations in Florida for more than 50 years, and every one of them is guaranteed by our 100 percent satisfaction guarantee! View a map of our service area in Florida.

Related reading:

  • Should I Repair or Replace My Water Heater
  • Should I Repair or Replace My Water Heater
  • Should I Replace My Water Heater There are three things to keep in mind:

What size of Rheem water heater do you need – Rheem Water Heaters

Sizing refers to the process of matching the capacity of a hot-water supply to the demands of a family or group of individuals.

  • The capacity of a tank water heater to store hot water is the most important consideration. The hot water flow rate is the most important consideration when purchasing a tankless water heater.

The temperature of the incoming water is a key concern, as it fluctuates according on the place and season. Thus, a water heater in the North – whether tank-mounted or tankless – will require more BTUs in the winter than in the summer to heat and supply water at a given temperature. What matters is that you begin with a lifestyle audit of your client’s usual water heater consumption, no matter what sort of heater is being utilized.

  • What is the number of persons showering and when are they showering? In the mornings or at night, is there a “shower rush hour”? Is there an extra-large soaking tub or a whirlpool? What is the capacity of the tank in gallons? And how do they make use of their tub
  • For example, do they first take a long shower before getting into a full tub
  • When do significant appliances come into play? Is it necessary to run the dishwasher and the washing machine at the same time as family members are showering? A residence with numerous hot water appliances in use at the same time is unusual in most parts of the United States since most people are accustomed to staggered hot water consumption. How much hot water is required to provide the experience that consumers desire throughout their bathroom remodeling project? As an example, do you have enough hot water to fill a deep-soaking whirlpool or to run a vertical spa-type shower for an extended period of time?

Determine the peak demand, which is measured in gallons per hour (gph). Then compare tank water heaters on the same gph basis in order to establish how many gallons of storage are required to achieve this need. In spite of the fact that tankless water heaters never run out of hot water, if the unit is not properly designed, the flow rate of the water might be significantly affected. However, the warmth of the shower will stay constant, but the flow rate may decrease to a trickle. For this reason, adding up the flow rates of all showerheads, faucets, and appliances that are likely to be in use at the same time is the first step in determining the appropriate size for tankless water heaters.

When the temperature of the incoming water drops into the 30s and 40s, more BTU inputs will be required.

Depending on the volume of water being heated, you may want to specify more than one tankless water heater unit, which may be placed independently or joined together to work as a single tankless system. This application will be made possible by the Rheem EZ-LinkTM technology.

Hot Water Usage Audit Questionnaire

  1. A number of bathrooms: the number of bathrooms in the house Showers: How many showers are there in the house, and how many showerheads, body sprays, and side sprays are there in each shower? How many showerheads, body sprays, and side sprays are there in each shower? What amount of water do they consume? Showerheads with a standard flow rate of 2.5 gallons per minute are available, while modern water-efficient showerheads have flow rates that are far lower. The majority of people feel comfortable taking a shower at water temperatures ranging from 102°F to 106°F. What is the number of bathtubs and whirlpools in the house? Bathtubs How many gallons are required to completely fill each container? Note: While small tubs typically contain 40 gallons or less, large soaking tubs can store up to 140 gallons or even more. Remember that most individuals bathe at temperatures ranging from 102°F to 106°F, just like they do when they shower. Bathing and bathroom usage schedules: What is the average bathing and bathroom usage routine in your home? Which of the inhabitants is most likely to be bathing at the same time. Other types of hot water appliances include: Are there any other hot water appliances that are in operation at the same time as this one? If this is the case, additional costs must be estimated, such as dishwasher, hot-water laundry, kitchen use, and so on. Geographical location: Where do you call home? Take into account the winter inlet water temperatures in the area to ensure that there is enough hot water flow on the coldest of days throughout the winter. i.40°F for the northern tier of states is considered to be the general rule of thumb. In most sections of the South, the temperature is ii.50°F. Southern California, the Southwest, and the Gulf states all have year-round temperatures of 60°F or higher. Calculate and choose the appropriate unit: Calculate your peak demand in gallons per minute and determine which size tank water heater will meet this demand during the coldest time of the year
  2. That is, when the temperature difference between the inlet and outlet water temperatures can reach as high as 75°F if you live in the Northeast or Upper Midwest. Consider this: If a Minneapolis resident chooses a system that can handle a Delta T of 75°F in the winter (45°F inlet to 120°F outlet) to meet the needs of a household that takes two showers at the same time every weekday morning, this consumer will not have to worry about the summer, when the inlet temperature should be 20°F to 25°F warmer.

What Size Water Heater Do You Need For Your Home?

A. O. Smith is delighted to be a leading producer of residential water heaters, owing to its more than 145 years of expertise in offering unique solutions, as well as its more than 80 years of experience in delivering innovative water heating solutions. Our water heaters are available in a range of sizes, features, and capacities, and are designed to give the best solution for the individual demands of your house, regardless of your lifestyle or geographic location. Contact us now to learn more.

More On Water Heater Sizing

Understanding how much and how frequently you want hot water is the first step in selecting the appropriate size of water heater. Consider the amount of people who live or are staying in your house, as well as their lifestyle choices, when establishing a benchmark. Consider the normal duration of showers taken, the number of showers taken back-to-back, the number of showers taken concurrently, and the size of the bathtub. Take into account other appliances that consume hot water, such as your washing machine and dishwasher, as well as how and when those appliances are frequently used as well.

Considering all of these considerations will help you choose the appropriate size of water heater for your property.

Determining Your Priorities

Your personal priorities will play a role in determining the appropriate size of water heater for your needs. Consider the sliding scale between the storage capacity of a water heater and the recovery rate of a water heater. This is the delicate balance between the amount of water your water heater can store and the speed with which it can reheat the water already in its storage tank. The most appropriate water heater for you is determined by what is most essential in your life. The storage capacity of tank water heaters makes them ideal for large-scale applications such as filling a large bathtub or taking numerous showers at the same time.

Instead, tankless water heaters create hot water on demand, making them ideal for prolonged hot water consumption such as back-to-back showers.

Find out more about tank and tankless water heaters by visiting our website.

Your Space Requirements

In order to determine the amount of space you have available for a water heater, you must first determine your hot water requirements and then prioritize your priorities. Storage space on a grand scale Tank water heaters take a big amount of room to be installed and may not be the best option for tiny homes. They are frequently found in basements, closets, and other locations away from the main living area. Tankless water heaters are an excellent alternative for individuals who have limited space in their homes since they are compact and can be put in spaces as tiny as a closet in your home.

When making a purchase decision, it is essential to consider the location where the water heater will be put and the amount of available space.

“Instant” Hot Water

A water heater, no matter what brand or kind (tank or tankless) it is, will not provide rapid hot water to a shower, faucet, or other device by itself. It is necessary to have the proper characteristics, capabilities, location, and technology in place in order to ensure that hot water is delivered immediately. The following are a few things that may have an influence on the amount of time it takes for hot water to reach your fixture. Capabilities: Instant hot water supply is made possible by the use of certain product characteristics.

Because of its proximity to the water fixture, the water heater will get hot water more rapidly if you do not have a recirculation pump built in conjunction with the requisite piping system.

Another aspect that may have an influence on hot water delivery is the temperature of the pipe that runs between the water heater and the position of the water fixture.

40 feet of pipe installed in a crawl space without recirculation help will take longer to provide hot water during a northern United States winter than 40 feet of piping installed in an attic during a southern United States summer, for example.

Help Me Choose!

Do you require further assistance? Check out our XPERT TM Water Heater Selection Tool for more information. Simply answer a few simple questions, and we’ll assist you in narrowing down your search to the top three options that best meet your preferences as well as the requirements of your residence.

Not sure which water heater is right for you?

Make use of our product picker tool to choose the best model for your needs. Please Assist Me in Making My Decision

Contractor Resources

  • Detailed Instructions for Setup Instructions for installing a water heater may be found here. See the document
  • Guide to Obtaining Resources Match the flow rate to the requirements of your customers. Cross-reference tool for viewing documents Look for replacement products that are NAECA-compliant. Make use of a tool.

How to Size Your Water Heater

Sizing refers to the process of matching the capacity of a hot-water supply to the demands of a family or group of individuals.

  • The capacity of a tank water heater to store hot water is the most important consideration. The hot water flow rate is the most important consideration when purchasing a tankless water heater.
See also:  What Should I Set My Hot Water Heater To?

The temperature of the incoming water is a key concern, as it fluctuates according on the place and season. Thus, a water heater in the North – whether tank-mounted or tankless – will require more BTUs in the winter than in the summer to heat and supply water at a given temperature. What matters is that you begin with a lifestyle audit of your client’s usual water heater consumption, no matter what sort of heater is being utilized.

  • The temperature of the incoming water is crucial, because it fluctuates depending on the region and the season. Thus, a water heater in the North – whether tank-mounted or tankless – will require more BTUs in the winter than in the summer to heat and supply water at a given temperature. Regardless of the type of water heater that is utilized, you should begin by conducting a lifestyle audit of your client’s regular water consumption.

Sizing Tank Water Heaters

Determine the peak demand, which is measured in gallons per hour (gph). Then compare tank water heaters on the same gph basis in order to establish how many gallons of storage are required to achieve this need. In spite of the fact that tankless water heaters never run out of hot water, if the unit is not properly designed, the flow rate of the water might be significantly affected. However, the warmth of the shower will stay constant, but the flow rate may decrease to a trickle. For this reason, adding up the flow rates of all showerheads, faucets, and appliances that are likely to be in use at the same time is the first step in determining the appropriate size for tankless water heaters.

When the temperature of the incoming water drops into the 30s and 40s, more BTU inputs will be required.

Depending on the volume of water being heated, you may want to specify more than one tankless water heater unit, which may be placed independently or joined together to work as a single tankless system. This application will be made possible by the Ruud EZ-LinkTM technology.

Hot Water Usage Audit Questionnaire

Questionnaire to be printed

  1. A number of bathrooms: the number of bathrooms in the house Showers: How many showers are there in the house, and how many showerheads, body sprays, and side sprays are there in each shower? How many showerheads, body sprays, and side sprays are there in each shower? What amount of water do they consume? Showerheads with a standard flow rate of 2.5 gallons per minute are available, while modern water-efficient showerheads have flow rates that are far lower. The majority of people feel comfortable taking a shower at water temperatures ranging from 102°F to 106°F. What is the number of bathtubs and whirlpools in the house? Bathtubs How many gallons are required to completely fill each container? Note: While small tubs typically contain 40 gallons or less, large soaking tubs can store up to 140 gallons or even more. Remember that most individuals bathe at temperatures ranging from 102°F to 106°F, just like they do when they shower. Bathing and bathroom usage schedules: What is the average bathing and bathroom usage routine in your home? Which of the inhabitants is most likely to be bathing at the same time. Other types of hot water appliances include: Are there any other hot water appliances that are in operation at the same time as this one? If this is the case, additional costs must be estimated, such as dishwasher, hot-water laundry, kitchen use, and so on. Geographical location: Where do you call home? Take into account the winter inlet water temperatures in the area to ensure that there is enough hot water flow on the coldest of days throughout the winter. i.40°F for the northern tier of states is considered to be the general rule of thumb. In most sections of the South, the temperature is ii.50°F. Southern California, the Southwest, and the Gulf states all have year-round temperatures of 60°F or higher. Calculate and choose the appropriate unit: Calculate your peak demand in gallons per minute and determine which size tank water heater will meet this demand during the coldest time of the year
  2. That is, when the temperature difference between the inlet and outlet water temperatures can reach as high as 75°F if you live in the Northeast or Upper Midwest. Consider this: If a Minneapolis resident chooses a system that can handle a Delta T of 75°F in the winter (45°F inlet to 120°F outlet) to meet the needs of a household that takes two showers at the same time every weekday morning, this consumer will not have to worry about the summer, when the inlet temperature should be 20°F to 25°F warmer.

What Size Water Heater Do I Need?

It makes all the difference when it comes to your comfort and your utility costs whatever size of water heater you get when purchasing a new water heater. If you choose a size that is too tiny, you will run out of hot water before the conclusion of your showers. If you go too big, you’ll end up paying more for hot water that you’ll never use. In order to guarantee that you get the proper water heater size, consider the following: Tank or tankless water heaters? That depends on the sort of water heater you’re looking to purchase.

Continue reading for step-by-step instructions on how to select the appropriate size for both tank and tankless water heaters.

Sizing a tank water heater

You simply need to consider two figures in order to decide the appropriate size tank water heater:

  1. When it comes to peak hour demand (the amount of hot water your home consumes during a busy hour), The tank’s FHR (the amount of hot water a heater can produce in a given period of time)

Your peak hour demand (i.e., how much hot water your home consumes during a particularly busy period). The tank’s FHR (the amount of hot water that a heater can produce in an hour’s time); and

Sizing a tankless water heater

The size of tankless water heaters differs from that of tank water heaters due to the fact that they operate differently. As opposed to preheating a vast volume of water that is readily available at all times, they heat incoming water just when it is required. Tankless water heaters are measured in two ways: first, by their capacity.

  1. Flow rate (the number of gallons of hot water per minute that you anticipate using at any given moment)
  2. Temperature increase (the number of degrees that the entering water must be heated before it can be utilized)

Calculate your flow rate and temperature rise by following the instructions in the chart and instructions below: Step 1: Choose the hot water appliances that you anticipate running at the same time on a regular basis. Step 2: Add the average flow (in gallons per minute) of all of the appliances together. This represents the flow rate in your home. The third step is to figure out the highest water temperature you’ll want to utilize and subtract it from the entering water temperature. The temperature of the entering water in Minnesota is around 40 degrees Fahrenheit.

Your flow rate would be 4-5 GPM at that point.

The temperature rise is calculated by subtracting the entering water temperature (120 – 40 = 80) from the temperature rise.

Please keep in mind that a temperature rise of 80 degrees at a flow rate of 5 GPM is considered to be the maximum for most home tankless water heaters.

Need help sizing and installing your water heater?

If you live in the Minneapolis-St.

Paul region and have more questions concerning your water heater, please contact us. Get in touch with MSP Plumbing immediately for expert guidance and a straightforward installation procedure.

Sizing Guide: What Size Water Heater Do I Need for My Home?

When it comes to water heaters, the typical lifespan varies depending on the sort of system you have. However, the kind of water available in your location will have an influence on the performance of your water heater system. A conventional gas water heater is designed to last between 8 and 12 years, depending on how well it is maintained. An electric water heater, on the other hand, is meant to have a life cycle of 10 to 15 years, depending on the manufacturer. Your water heater may need to be replaced if it is leaking or making loud noises.

It’s crucial to become familiar with the different water heater sizes available before making a decision on which system to purchase.

Water Heater Sizes

What size water heater do you require to meet the needs of your household? If you have a large number of children, the answer to this question will be different for each one. For example, a household of three to four people should acquire a water heater that holds 50 to 60 gallons. A home of 5 to 7 people, on the other hand, may require a water heater with a 60 to 80 gallon water tank. An 80 gallon water heater will offer you with adequate hot water to shower, do laundry, and wash dishes if you live alone with your spouse.

The size of your water heater will be determined by a variety of factors, including the number of people in your household and the length of time you spend in the shower on average.

Hot Water Usage Habits

The procedure of determining the appropriate size for a water heater will vary from family to family. If a family of 5–7 people lives in a 60–80 gallon water heater, for example, this may not be necessary. If you have a household of this size, a 50–60 gallon water heater may be sufficient for your needs in some instances. In addition, a water heater with a water tank that is bigger than 30 gallons may be required for a household of two people. It is dependent on your water use patterns that the size of your water heater will be determined.

The process of determining the appropriate size of a water heater for your home is quite crucial.

As an added bonus, a water heater that is too small for your household will have to work harder to keep up with your demands.

Alternatively, a water heater that is too large for your home may result in a rise in the overall cost of your energy bills.

If you need assistance choosing what size water heater you require, contact a local specialist in your region who can assist you in identifying the most appropriate type for your home. Continue reading:How Big of a Condensing Furnace Do I Need?

How to Determine How Much Water You Use

While the estimations provided above can be used to get an approximate idea of the amount of water heater you will want, there is a more exact technique of determining the size of a water heater. First and foremost, you must examine your water use patterns in order to estimate your peak water consumption hour. If your family showers from 8:00 a.m. to 9:00 a.m. every morning, this is the time of day when you use the most water. You’ll need to figure out how many gallons of water you use throughout this period of the day to be accurate.

  • If there are a total of 5 people in your household who shower in the morning, you should multiply 10 gallons by the total number of water usage sessions, which is 5.
  • This means that a family of five would consume 50 gallons of water each morning from 8:00 a.m.
  • However, it is probable that you will consume more than 50 gallons of water to wash the dishes from your meal.
  • Your total water use will be equivalent to 56 gallons once you have finished washing your dishes, assuming that each member of your household takes a shower.
  • 63 gallons of water have been consumed by your family after everyone has done bathing, cleaning dishes, and doing laundry.
  • The First Hour Rating (FHR) of a water heater should be more than the entire volume of water consumed during your highest water usage hour, which you should look for while comparing different water heater sizes at the store while shopping.
  • This rating may be obtained on the website of the manufacturer.
  • It will be situated at the top of this sticker on your water heater, and it will read “FHR Rating.” More information may be found at: Reasons Why It’s Critical to Replace Your Lead Pipes

Other Factors to Consider While Sizing Water Heaters

The size of your water heater may be increased if one or more persons in your household choose to take a bath in the morning instead of showering. A basic little bathtub has a capacity of 40 gallons of water on average, which is plenty for most people. A huge bathtub, on the other hand, may be able to accommodate up to 140 gallons of water. We propose that you have your children reuse the same bathwater in order to save money on your water costs. If you choose to acquire a tankless water heater rather than a typical water tank, you will be required to follow a new set of rules when determining the appropriate size for your water heater.

  • The Flow Rate and Temperature Rise should be calculated in order to establish the size of the tankless water heater that you will require.
  • Giant gallons are used to measure the entire volume of water.
  • If you want assistance in determining the appropriate size water heater for your home, please contact our staff at (484) 206-8594.
  • Additionally, we offer a variety of other services such as water line installation, air conditioning tune-ups, furnace repairs, and drain cleaning, among others.

In addition to West Chester, Broomall, Coatesville, and Conshohocken, WM Henderson provides plumbing and HVAC services across Pennsylvania. Since 1977, we’ve been offering trustworthy plumbing, heating, and air conditioning services to people of the Commonwealth of Pennsylvania.

What Size Water Heater Do I Need?

Please keep in mind that this content may contain affiliate links. This means that, at no additional cost to you, we may gain a small profit on purchases made via our links. Tankless water heaters are becoming increasingly popular (particularly in bigger houses), but traditional tank devices are still far more widespread and are not likely to become obsolete any time in the near future. So, how can you choose which one is the greatest match for you? It’s a straightforward process. Simply begin with the fundamentals.

See also:  How To Get Frigidaire Water Filter Out?

What is the Capacity of a Water Heater Measured In?

First and foremost, let’s get this over with. What units does the capacity of a water heater tank have to be measured in? In the United States, where the imperial system is in use, the capacity of a water heater is measured in gallons of water. The most often seen capacities are between 40 and 60 gallons. Litres are used to measure the holding capacity of a water heater in nations that use the metric system instead of the imperial system.

Storage Tank Water Heater Sizes

Before we get started, a little reminder that What unit of measurement does the capacity of a water heater tank have? Water heater capacity is measured in gallons in the United States, where the imperial system is used. The most often seen capacities are between 40 and 60 gallons in size. Water heater storage capacity is measured in Liters in nations that use the metric system rather than the imperial system.

  1. In a busy 1-hour period, the amount of hot water consumed by your family is known as peak hour demand. The First Hour Rating (FHR) of a water heater is the amount of hot water that the water heater can produce in one hour.

Make some calculations in order to ensure that you choose a water heater that is the proper size for your residence. You should add up the total heat energy required by all of your home’s hot water equipment that you anticipate will be used in a period of one hour. Using the chart above, calculate the average number of gallons of hot water consumed by each of these devices using the formula. Consider the following scenario: two showers are taken, and the washing machine is started in the meantime.

During that one-hour period, you would require a water heater with a “first hour rating” of at least 72 gallons in order to avoid running out of hot water.

An ordinary family of four would consume around 200-400 gallons of water each day for activities such as dishwashing, bathing, laundry, and other household chores.

The size of the tank is mostly determined by how much water you use each day, rather than by the number of people in your household (some individuals use more water than others).

Those who live in a large house with a master bath that is located on the other end of the house from the water heater will require a larger tank than those who live in a home with the majority of the water outlets located near to the water heater.

Tankless Water Heaters Sizes

They are ideal for larger families who require hot water from multiple sources at the same time or who have a large Jacuzzi tub in their bathroom. Tankless water heaters are great for saving money on water consumption and are ideal for larger families who require hot water from multiple sources at the same time or who have a large Jacuzzi tub in their bathroom. Because of their small size, they are easier to conceal than larger tank versions, which can be a problem with particular models. Tankless water heaters are measured in gallons per minute.

  • Add up all of the hot water that you will be utilizing at the same time. Consider the following scenario: you want to hop in the shower but you also need to run the dishwasher at the same time. The average water consumption rates for each are as follows: 1.5 – 3.0 gallons per minute for a shower and 1.0 – 3.0 gallons per minute for a dishwasher. On the high end, that’s 6 gallons per minute
  • The average groundwater temperature varies depending on where in the United States you reside, and how far north or south you are. Overall, people who live in northern climates will require a more powerful tankless water heater than those who live in warmer climates because it takes more effort to heat up cooler groundwater. Once you have determined the number of gallons per minute you require and the appropriate groundwater temperature, you can determine which tankless water heater is the most appropriate size for your home. After selecting a brand, most tankless water heater manufacturers will include a water heater size calculator on their website, as well as model suggestions once you’ve made your decision.

Whether you choose a tank or a tankless system, keep in mind that you should plan for the long term and consider purchasing the next size up in case your family expands suddenly (or if single you decide to get married). Finding the proper size and kind of water heater does not have to be a time-consuming and complicated procedure. Within minutes, you’ll have the appropriate size water heater for your house, thanks to some simple arithmetic and personal preference.

Water Heater Sizing Guide – Tips for Proper Sizing

AO Smith is a fictional character created by American author A.O. Smith. It is recommended that you familiarize yourself with the water heater sizing recommendations before beginning your search for a new electric or gas tank-type water heater. By choosing the appropriate tank size, your home will have sufficient of hot water accessible even during peak usage hours, while not wasting excessive amounts of electricity or water in the process. Due to the fact that it contains professional guidelines, recommendations, and ideas from a variety of manufacturers, it is really useful.

  1. Get Free Estimates on Your Project!
  2. It is really the second-largest energy consumer in North American households, and with the growing costs of natural gas, crude oil, and electricity, you need be cautious when choosing the right size water heater for your needs.
  3. Keep in mind that using an excessive heater will result in money and energy being wasted since you will be heating more than you require.
  4. A water heater that is undersized will cause issues, whereas a water heater that is appropriately sized will fulfill all of the household’s hot water demands.

Water heater sizing guide tips

An early version of this article appeared in the print edition of The New York Times on February 6, 2018. It is recommended that you familiarize yourself with the water heater sizing recommendations before beginning your search for a new electric or gas tank-style water heater. By choosing the appropriate tank size, your home will have sufficient of hot water accessible even during peak usage hours, while not wasting excessive amounts of electricity or water in doing so. In addition to expert instructions, recommendations, and ideas from various manufacturers, the book is really beneficial.

Estimates are provided at no charge.

As the second-largest energy consumer in North American households, and with the growing costs of gas, oil, and electricity it is important to be cautious while selecting the appropriate size water heater.

Please keep in mind that heating more than you require with an excessive heater will result in money and energy waste.

Through the tank walls and pipelines, the heat energy will be lost, resulting in an excessive amount of water being re-heated on a regular basis. A water heater that is too small can cause issues, but a water heater that is too large will not provide enough hot water for the entire family.

Is your water heater undersized?

A heater that is too small will not deliver enough hot water, and it may even result in overheated water. Due to drops into the flame, it may also cause condensation and a pilot flame to go out on the stove. The following are some of the most common signs of an undersized water heater:

  • There isn’t enough hot water. Condensation in abundance
  • On the burners and flue tubes, there are rust chips. Failure of the tank before its time

Because improper water heater sizing might result in problems that shorten the heater’s life expectancy, undersized systems are not eligible for consideration under the warranty. The purchase of an appropriately sized tank, on the other hand, will decrease burner or other element activity when just a small quantity of hot water is required, resulting in less stress on these components. Sizing also refers to being appropriate:

  • Water heating power in kW
  • Pipe size to give sufficient flow and output
  • Ampacity
  • Gas pipeline
  • Drain pipeline
  • Vents to manage total BTU input a pace of recovery
  • Electrical fuses
  • An expansion tank
  • Air drawn from the specified aperture size
  • And other related items.

Important factors to consider

The storage (capacity) and the heat input are two of the most significant aspects to consider. Having the proper water heater size is critical, especially when significant amounts of hot water are required in a short period of time. On the other hand, if the peak consumption period lasts for a lengthy period of time (greater than two hours), the heater recovery rate becomes increasingly essential. Another expert recommendation is to choose a heater with the greatest Energy Factor possible (EF or UEF).

Even though they are more expensive, with a higher EF, you will be able to purchase Electricity Starmodels, save money on energy, and qualify for a refund through government programs.

A water heater’s physical limits, such as its diameter and height, must be considered before purchasing one.

Here are some recommendations and significant aspects to consider when purchasing a water heater, all of which have a direct impact on water consumption:

  • What is the total square footage of your house and family? Determine if your household has a low or a high need for hot water on a regular basis. If there are more than two baths in a home, if there are at least two adolescents in the home, and if you are utilizing a hot tub or whirlpool bath, you are in high demand. What is the number of bathrooms, baths, dishwashers, and washers you have. if there are any future additions
  • Family members’ ages, children’s ages, teens’ ages The family is expanding
  • I’m curious about the usage trend. Fixtures in terms of quantity and type

Because it offers you an indication of peak hour demand or when the busiest hour of usage occurs, it is vital to understand the usage pattern (i.e., peak time might be in the morning between 6 and 7 before parents go to work and kids to school).

Calculate how much hot water do you need

As an illustration of how much water is required for a certain application, the following consumption rates are provided as examples:

  • For a shower or bath, around 20 gallons of water are required. When using the energy-efficient shower head, the flow rate is 2.5-3 gal/min. Automatic dishwashers require around 14 liters of water and a flow rate of 1-2.5 GPM. A flow rate of 1.5-3 GPM is required for the clothes washer. To wash the garments, the washing machine requires 32 liters of water. You’ll need around 2 liters of water to shave.

Around 20 liters of water are required for a shower or bath. The flow rate of 2.5-3 gal/min during showers with the energy-efficient shower head; It takes around 14 gallons of water and a flow rate of 1-2.5 GPM for an automatic dishwasher. A flow rate of 1.5-3 GPM is required for the clothes washer; nevertheless, In order to wash the garments, the washing machine requires 32 gallons. About 2 quarts of water is required to shave;

Sizing and first hour rating chart

Avoid making the same error as the majority of consumers and purchasing a water heater based on the size of the storage tank. The ability to meet peak hour demand or the first hour rating is more significant. It is possible to find this information on the Energy Guide label or in the Energy Guide booklet. The first hour rating is a measure of how much hot water a single unit can supply in one hour. For natural gas, for example, the first-hour rating might range from 40 to more than 100 gallons depending on the source.

Consider the following scenario: A 40-gallon natural gas heater holds 31 gallons of useable hot water and provides 41 gallons of usable hot water in the first hour, yielding a first hour rating of 72 gallons for the heater.

The following is what we discovered after consulting the AO Smith water heater selection guideline for a variety of household sizes: The number of people in the family 2 persons are involved.

3 persons are involved. a group of four persons a group of five persons a total of six persons a total of seven persons Requirement for FHR (gal) 45-55 55-65 65-75 75-85 85-100100 45-55 55-65 65-75 75-85 85-100100

Sizing calculators

  • Size calculator for Bradford White
  • State sizing calculator for Bradford White

What are the popular sizes?

In the United States, the most often utilized tank size (based on a typical family size of four to six people) and the general guideline for water heater sizing are as follows:

  • 30 gallon unit – sufficient for a one-bathroom residential house or apartment building
  • 40-gallon water heaters are recommended for two-bath residential houses or two applications
  • 50-gallon water heaters are recommended for three-bath residential homes or three applications. Take a look at the best gas and electric vehicles

As a general rule of thumb, if you want to use an electric heater for a family of four in a home with two full bathrooms, as well as a washer and dishwasher, your tank size should be in the 50 to 80 gallon range and the power provided by the heating elements should be around 5.5 kW. It is recommended that a 50-gallon tank with a gas input of 40,000 BTU/hr be used for the same requirements if gas is being used instead of electricity in this case. When sizing a water heater, keep the following factors in mind:

  • Because of the immersion installation of electric heaters, they have recovery efficiencies that are near to 100 percent. Gas heaters have a recovery efficiency of roughly 75%, which implies that the water absorbs 75% of the total heat produced by the burner in the tank, with the remaining 25% being wasted as energy. Additionally, keep in mind that around 70% of the hot water is pulled out before being diluted by the entering cold water. The hot water produced by a 50-gallon tank, for example, will be 35 gallons per hour of useable hot water.

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