You Should Swaddle Your Electric Water Heater in an Insulating Blanket.
In the ten years I spent outside the United States, none of the homes I lived in had hot water available 24 hours a day. The hot water storage tanks were small and when they were empty, the entire hot water supply was gone. To get more, you had to turn on the water heater and wait at least half an hour until there was enough water in the tank to take a decent shower or wash the dishes.
This took some getting used to at first, but once I got used to heating only the water I would use immediately, I came up with the idea of having a giant tank that not only stores a large amount of hot water, but also keeps it warm. 24/7 sounded a) luxurious and b) extremely expensive. Now, back in the US, I can confirm that I was right on both counts. Luckily, there is a way to help our water heater maintain the desired temperature in the water tank without wasting a lot of energy: by wrapping it in a special insulating blanket. Let’s get comfortable.
What is a water heater blanket?
A water heater blanket, also known as a jacket, is exactly what it sounds like: a sheet of insulation made of fiberglass, foam, foil, or a combination of materials that wraps around the water heater tank to help it maintain its temperature. . Because less heat is lost from the tank, the water heater won’t have to use as much energy to keep the water inside it hot.
These insulating blankets are especially useful if your water heater is located in the basement rather than in a utility room on or above the first floor, since it is likely to be colder there and will therefore need to use more energy to maintain the water. It’s hot inside the tank.
Recommended Products:
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Reflective Foil Water Heater Jacket ($38.88)
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Frost King SP57/11C All Season Water Heater Insulation Blanket ($30.47)
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US Energy NASATECH Water Heater Insulating Shell Kit ($44.44)
What is R-value?
When looking at water heater blankets or even the tank itself, you may come across a rating called R-value, which is determined by how effectively the insulation material resists heat flow. The better the insulation, the higher the R-value.
According to the U.S. Department of Energy (DOE) , your water heater tank itself should have an R-value of at least 24. You can usually find the R-value on a label on the tank or in the owner’s manual, but if you can’t, carefully touch the outside of the tank: if it hot or warm, it probably needs to be insulated, but the DOE recommends insulating it even if it doesn’t.
Do water heater blankets really work?
The Department of Energy estimates that your water heater blanket should pay for itself in about a year. That’s because the agency estimates that insulating your water heater tank can reduce standby heat loss by 25 to 45 percent, which should result in savings of about 7 to 16 percent in water heating costs.
Although most of these blankets state that they can be safely used in both electric and gas water heater tanks, according to the Department of Energy website , “most experts agree that heat loss in a gas water heater goes up the chimney.” Thus, the blanket is “useless for this type of heater.” However, others have noted that if your gas water heater is old and the tank is poorly insulated, a blanket should help at least a little—just make sure it doesn’t block the flue or cover any part of the chimney. the blanket touches the bottom of the heater (or where the flame is).
Finally, the Department of Energy also recommends checking local utility codes before purchasing or installing insulation sheeting, as it is prohibited in some areas.
What to look for when buying a water heater?
The most important decision you will have to make when purchasing a water heater blanket is whether to make it fiberglass or not. While fiberglass is the thickest and most effective type of hot water tank insulation, it is also messy, leaving behind small fibers that spread everywhere and are hazardous to breathe in (which is why you need to wear a mask when working with it). It is also unpleasant and itchy to touch.
If you’d rather avoid fiberglass, you can purchase a water heater blanket made from foil, foam, and (special) bubble wrap. It is not as effective as fiberglass, but it is easier (and less awkward) to install.
Most water heater blankets cost anywhere from $30 to $50 and are easy to install yourself, especially since they are usually pre-cut to the size of your tank, often as part of a kit, along with heat-resistant tape, step by step. instructions, and sometimes even a small knife for cutting off excess insulation. Here are some of my favorites:
Reflecto-Foil Water Heater Jacket ($38.88): This kit includes enough material to cover a 40-gallon tank, but a larger kit is also available. In addition to reflective foil and tape, the kit also includes a small utility knife.
Frost King SP57/11C All-Season Water Heater Insulation Blanket ($30.47): This three-inch thick fiberglass blanket with a vinyl backing provides the superior insulation of fiberglass but with less loss than other products made from the material. It’s supposed to fit hot water tanks up to 60 gallons, but in practice it can be difficult to fit in tanks larger than 50 gallons (unless you want to really stretch it).
SmartJACKET Water Heater Insulation Blanket ($47.85). Made from 99% aluminum foil, this insulating blanket is designed to fit most water heater tanks ranging from 20 to 80 gallons.
Reach Barrier 3016 Water Heater Insulation Kit ($33.73): This kit includes a pre-cut panel of foil-covered bubble insulation and heat-resistant tape, making installation quick and easy.
US Energy NASATECH Water Heater Insulation Shell Kit ($44.44). This fiberglass-free insulation kit includes 42 square feet of material that fits most tanks from 20 to 80 gallons.
Be sure to measure your water heater tank before purchasing: these blankets are not one size fits all.