A lot of people are looking to buy appliances that have low to moderate energy consumption. Not only will these appliances allow you to save on your electricity bill, but it will also benefit the environment. When it comes to water heaters, energy efficiency is an important consideration. Especially, seeing that these heaters are one of the top energy-consuming appliances.
Because of this, plumbing professionals and contractors are often consulted when a customer is looking to find a high-efficiency water heater. To help in this regard, the Environmental Protection Agency, also known as the EPA, developed the Energy Star Program. This helps to aid customers in pinpointing high-efficiency water heaters and other appliances. In this post, we look into the water heaters energy star rating in detail.
How Products Earn The Energy Star Label
Not all appliances are created equally. Various models’ output relative to their energy requirements can differ quite a bit when comparing all of the models on the market. How does one know which appliances will require less energy?
The answer lies in the Energy Star label. When a water heater is Energy Star certified, it means that it is more energy-efficient than heaters that are not certified.
There are various factors that can qualify a water heater to become Energy Star certified. First, Energy Star appliances should be able to provide a customer with significant energy savings without performing poorly. When it comes to water heaters, acquiring an Energy Star label is difficult. The energy efficiency standards that qualify the product are very high in this category.
Among other things, certain requirements have to be met for the appliance to become eligible for the Energy Star Program.
Second, if the product meets these requirements, then it is classified as eligible. Then, the product would also have to meet the criteria set forth by the EPA to earn the Energy Star Label.
The EPA criteria can also vary depending on the type of water heater. The standards of the Energy Star Program are also not set in stone and subject to change.
Water Heaters Energy Star Program Requirements
As previously mentioned, a water heater must meet certain requirements for it to be eligible for the Energy Star program. These requirements vary depending on the type of heater you are trying to qualify for the program. Storage, tank, and tankless water heaters all have different requirements.
High-efficiency gas storage water heaters must comply with the following:
- Have an input of 75,000 Btu per hour or less.
- Store between 20-100 gallons of water
Electric water heaters heat pump storage models must comply with the following:
- A maximum current rating of 24 amperes
- An input lower or equal to 250 volts
- Store a maximum of 120 gallons of water.
Tank water heaters or storage tanks must comply with the following:
- Store and regulate the water’s temperature up to a maximum of 180 F, no matter how the appliance is powered.
- The production of heat must be activated when water flow is detected in the tank.
- When it comes to capacity, the water tank must be able to contain 1 gallon of water per 4,000 Btu per hour of input.
- An input of 50,000-200,000 Btu per hour is required
Only when an appliance meets all of the above requirements can it be considered eligible for water heaters Energy Star certification.
Energy Star EPA Criteria For Eligibility
After reviewing a water heater’s Energy Star program requirements and finding that it is indeed eligible for the program, it must then meet the EPA criteria for both safety and efficiency. If the product meets the EPA criteria, it will then be qualified to earn the Energy Star label.
EPA Criteria For Electric Tank Water Heaters
As with the program requirements, the EPA criteria also differs based on the type of tank you have.
If you have an electric tank water heater you will have to make sure that the energy factor (EF) rating is at least 2.0 for tanks with a 55-gallon capacity. If your tank can hold more than 55 gallons, your EF rating will have to 2,2 at minimum to ensure high efficiency.
Furthermore, the first-hour rating (FHR), which is a rough estimation of how much water a unit will heat within the first hour of the heater reaching its top temperature, needs to be at least 50 gallons or more.
Another important criterion to meet is the manufacturer’s warranty requirements. The appliance must be covered for a minimum of six years on sealed systems.
Electric tank appliances must also meet UL 174 and UL 1995 requirements to fully ensure the unit’s safety. Lastly, the unit should be able to report the ambient temperature at which it operates.
EPA Criteria for High-Efficiency Gas Tank Water Heaters
With a high-efficiency gas tank water heater, it needs to ensure that the energy factor rating is at least 0.67 for heaters with a 55-gallon capacity or smaller. If the tank has a storage capacity of 55 gallons or more, the EF rating will have to be 0.77 or more. When it comes to the first-hour rating, the unit will need a rating of 67 gallons per hour minimum.
As with the electric tank model, the manufacturer’s warranty on a high-efficiency gas tank water heater must be valid for 6 years or more. The appliance must also meet the requirements of ANSI Z21.10.1/CSA 4.1. to ensure the safety of the unit.
EPA Criteria for Tankless Water Heaters
Tankless water heaters must have an energy factor rating of .90 or higher and be able to supply 2.5 GPM of water over a temperature of 77°F.
As in the case with all the other water tank heaters, the manufacturer’s warranty should cover the unit for a minimum of 6 years, with a 5-year cover for the unit’s individual parts. Lastly, the unit should meet the safety spec requirements of ANSI Z21.10.3/CSA 4.3.
The Energy Star Rating
When trying to understand the test benchmark, one should remember that the water heaters energy Star Rating is based on the energy input that is necessary to raise the temperature of 200 liters of water from about 60 to 140°F.
If your appliance is 100% efficient, then your energy input would be roughly 13761 MJ per year.
However, this is rarely the case since no application is 100% efficient. So in essence, the Star Rating Test calculates the actual amount of megajoules the appliance consumes to produce 200L of water at 140°F.
The maximum temperature in the test is set to 140°F because that is the minimum temperature setting required for the storage of water systems to prevent the build-up of bacterial growth or any other pathogens that could be harmful to humans.
One example of an Energy Star rated water heater is the Rheem Performance Platinum. This energy-efficient water heater has a temperature range between 37-145 °F. You can read the full review here.
Tankless water heaters that continuously flow do not allow for the build-up of bacterial growth so they typically only go up to about 122 °F, which means they are even more energy-efficient.
The Difference Between Each Star
If you’re wondering what exactly determines the difference between each star in the water heaters Energy Star Program, the answer is pretty straight forward. In order to get a 1-Star rating, the base energy consumption of the appliance should be 28900 MJ maximum per year.
To get a star increase, it should increase in energy efficiency. More specifically, a one-star increase requires a 7% increase in efficiency which roughly translates into an energy input reduction of 2023 MJ per year.
The more stars a heater has, the more reductions in energy it needs to have. For example, 5-Star and 6-Star ratings require 28% and 35% energy reductions, respectively. As technology advances, some appliances claim to be nearing 7 Stars, which means that if we continue on this energy reducing trend, customers will definitely be able to use electricity more sparingly in the future.
Combustion Efficiency for Each Star certified Rating
It is important to remember that Star Ratings encapsulates both the start-up heating factor and the combustion efficiency into consideration when it comes to water heaters.
Based on the specific Star Rating you choose, you will have a good idea of the combustion efficiency of your appliance. Products that earn a 4-star rating have a combustion efficiency of 73%. However, 5-star heaters have 80% efficiency. While products that earn 6- and 7-star ratings will definitely be a bit more expensive, they can provide you with a combustion efficiency of 87% and 94%, respectively.
The Bottom Line On Energy Star Certified Water Heaters
So, that’s everything you need to know about water heaters Energy Star Rating. With energy efficiency becoming a really hot topic, knowing exactly what you can expect from your residential appliances is important to save on your monthly electric bill.
Whilst some Star Ratings indicate a higher level of energy efficiency, even just investing in an appliance with the lowest Star Rating will still be able to save you money in the long run. You don’t need the highest efficiency model to save some money!
Apart from saving hot water heating costs, the Energy Star Program also enables you to have a smaller overall carbon footprint. This contributes to a more sustainable way of living.
Be sure to check the energy label of each appliance before you buy, and thoroughly research each water tank’s capacity and the water heater energy efficiency rating before making your choice.