The Safe-T-Cover Blog

The Best Place To Put A Heater in an Aluminum Enclosure

Posted by Craig Carmon on December 27, 2018

aluminum enclosure

When designing an aluminum enclosure for your backflow preventer, it’s easy to overlook freeze protection. But if you don’t take the proper steps to insulate and heat your enclosure, you could end up with a frozen backflow preventer and huge problems. Heaters for aluminum enclosures can maintain freeze protection in the harshest environments, depending on where it’s placed.

It’s important to remember that more than half of the United States and all of Canada will average a temperature of 32 degrees or lower during its coldest month. In fact, according to the National Weather Service, some states will see the temperature drop below freezing as early as August. But a heater allows you to keep your backflow enclosure at a steady, warm temperature.

That’s why it’s critical to install your heater in the optimal location. So, let’s look at the three types of heaters to consider for your aluminum enclosure and the best place to install it.

Types of Aluminum Enclosure Heaters

When you’re designing your aluminum enclosure, you must consider the type of heater you may need. The most common types of heaters to consider for your design are:

  1. Self-Regulating Heat Cable
  2. Wall-Mounted Heater
  3. Slab-Mounted Heater

Each has unique characteristics, but keep in mind that all heaters are not created equal. The most cost-effective solution may not always have the lowest initial price or offer the best protection. Here’s a closer look at each option:

Self-Regulating Heat Cable

Self-regulating heat cables automatically adjust their power output to compensate for temperature changes. When the ambient temperature drops, the cable’s power increases, and more heat is produced. Conversely, when the ambient temperature goes up, the cable’s power output goes down and it produces less heat.

The self-regulating heat cable is wrapped around your backflow device and plugged into a power outlet. It can protect your backflow preventer, but most enclosure manufacturers only provide the heat cable option for small-diameter pipes.

Wall-Mounted Heaters

If your backflow preventer has pipes bigger than 2 inches in diameter a heat cable may not be enough to keep it from freezing inside your aluminum enclosure. You may need a wall-mounted heater. In fact, most heaters in the industry are wall mounted, but that doesn’t necessarily make it the most cost-effective or safest option.

Safe-T-Cover's King Heater is a wall-mounted-heater, features a built in thermostat and meets ASSE 1060 Class 1 for use as freeze protection.  But most wall-mounted-heaters are noncompliant with the ASSE standard and simply are unable to deliver the most effective amount of freeze protection to keep your backflow preventer safe. 

Wall heaters must be mounted to one side due to doors and access panels. And because most wall heaters are not wet/damp certified, they must be mounted at least 12 inches off the slab, which creates another concern.


Heated air always rises, so your heater’s warmth channels are heading straight out of the top of your aluminum enclosure long before uniform warmth is achieved. You’re not getting what you paid for because there’s still a good chance your pipes will freeze. If that happens, you’ll not only have to pay to have your backflow preventer replaced but cover the losses tied to the building being without water while the repairs are made.

Slab-Mounted Heaters

A slab-mounted heater is your best option. It’ll provide the peace of mind you’re looking for because of its many features, including:

  • Meets all ASSE 1060 requirements.
  • Provides heat to the equipment inside your aluminum enclosure as well as the riser pipes beneath the slab.
  • Will maintain an interior temperature of 40 degrees— even with an outside temperature as low as negative 30 degrees. Enclosure Heater

Safe-T-Cover’s patented slab mounted heaters are also certified for wet/damp conditions, which is necessary for any enclosure that is not watertight.

Slab-Mounted Best For Aluminum Enclosures

Our HCH Series Floor Heater bolts directly to the slab, producing radiant heat that penetrates 16 inches down into the vertical pipes. The system is also designed to withstand water spray conditions inside the aluminum enclosure.

Safe-T-Cover also doubles the roof insulation to R-18, which not only keeps your pipes warm but also dampens the noise. It’s also more cost-effective because this method allows for 25 percent fewer thermostat on/off cycles on cold-weather days.

You can even purchase an alarm and add it to your enclosure that will alert you if there is a power failure. 

As a design engineer, specify an ASSE 1060 class 1 enclosure and you can rest easy knowing the owner will never call you and ask why the backflow device is frozen. Mother Nature surprises us all of the time—even Florida and Nevada can freeze sometimes.

If you’d like more information on the type of aluminum enclosure you might need, and the cost to heat it, download our free pricing table. It’s designed to help you to quickly understand the range of enclosure options and considerations.

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Topics: Enclosure Materials