BACKFLOW ENCLOSURE HEATER FOR FREEZE PROTECTION

Safe-T-Cover offers aluminum enclosure heaters to maintain protection in even the harshest environments. To best keep your device at a steady temperature, you should consider a slab-mounted heater. Below are some of the most frequently asked questions we receive about heating aluminum enclosures.

Backflow Preventer Freeze Prevention

Learn more about the benefits of even heat distribution with a patented Safe-T-Cover slab-mounted heater, the ASSE 1060 Class I standard and how heated enclosures help prevent backflow preventers from freeze-related failure.

Do I need an enclosure heater?

In any area where temperatures can fall and stay below 32°F for more than 24 hours, our recommendation is to add an enclosure heater. This seems to be one of those 'pay me now or pay me later' decisions we all deal with. As a design engineer, insisting on an ASSE 1060 Class I conforming enclosure allows me to rest easy knowing the owner will never call and ask why their backflow device is frozen and who will be paying an expensive backflow replacement bill, not to mention recouping losses due to a building being without water until the repair is made.

We routinely sell enclosure heaters for projects in the Sun Belt states: Texas, Louisiana, Mississippi, Alabama, Georgia and Florida. Mother Nature has surprised us in recent years: even Florida and Nevada can have very low temperatures, causing backflow preventers to freeze and fail. This post about backflow cages goes into more detail explaining why they're not a sufficient option for total protection.

What types of enclosure heaters are available and how do they work?

Wall-Mounted Heaters

Wall mounted heaterMost backflow cover heaters in the industry are wall- or panel-mounted. This method is simply unable to deliver equivalent freeze protection provided by a floor- or slab-mounted heater. Because of the door configuration, wall-mounted heaters must be mounted to one side and may use an aluminum mounting plate. And because they do not meet wet/damp requirements, they must be mounted at a minimum of 12” off the slab. Remember that warm air always rises, so these heaters' warmth channels straight out of the top of the enclosure long before uniform warmth is achieved, if at all.

Slab-Mounted Heaters

Slab mounted heaterOn the other hand, a slab-mounted enclosure heater provides heat to both the backflow equipment and up to 16 inches beneath the slab for the riser pipes. These heaters will maintain a standard interior temperature of 40°F with an outside temperatures as low as –30°F as is needed to meet ASSE 1060 Class I requirements. Safe-T-Cover's patented slab-mounted heaters are certified for wet/damp conditions, obviously necessary for waterworks equipment in outdoor conditions. Their rugged and compact design has proven reliable for backflow preventer protection in frigid low temperatures for years. 

Heat Wrap Cable

Heat wrap cableWe also offer a self-regulating heat cable. This enclosure heat option is wrapped around the backflow device. Most enclosure manufacturers, including Safe-T-Cover, only provide a heat cable option for pipe diameters two inches or less in small enclosures.

This video from Instrument Specialties is a good overview of how these cables work.

How much heat do I need and what power options are available?

Safe-T-Cover offers 1000 and 2000 watt slab-mounted box heaters at 120V and 240V heating power. You should set the thermostat for wall- and slab-mounted heaters at 40ºF and the heater will maintain this temperature all the way down to –30ºF. Safe-T-Cover has sold enclosure heaters for many years in Canada and in upstate New York, where winter temperatures can remain below freezing for extended periods of time. For more information, you can read our case study from St. John's, Newfoundland about how well enclosure heaters perform in harsh environments.

What happens if the power fails?

Alarm systemBe Prepared is the Boy Scout motto, and Safe-T-Cover also advocates being in that state of readiness. The first and foremost way to prepare against freezing pipes is to know the power has failed at the enclosure. We offer three different power and temperature failure alarms. There are basic models with a light and alarm, and systems with remote monitoring and cell phone alerts. 

The second way you can be prepared is by having a contingency plan to provide some type of box heating for the enclosure if it appears the power might be out for an extended period and the temperatures will remain below 32ºF. A 9,000 BTU portable propane heater will more than replace the output of an electric heater.

How is temperature controlled? Where is the thermostat installed?

For wall-mounted and slab-mounted enclosure heaters, a thermostat determines when the heater will activate. Most wall-mounted heater thermostats are built into the heater body and located high enough on the wall for the heater to be safe from water damage. For a slab-mounted enclosure heater, the thermostat is installed about 12” above the slab. The thermostat is set at 40ºF and designed to maintain this temperature inside the enclosure all the way down to –30ºF. That is, if the box heater satisfies ASSE 1060 Class I requirements.

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Will I need heat for the enclosure?

In any area where temperatures can fall and stay below freezing for a day or two, our recommendation is to add heating to the enclosure. This seems to be one of those "pay me now or pay me later" type of decisions we all deal with. 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 and who will be paying for an expensive backflow replacement bill. Not to mention the losses due to the building being without water until the repair is made. We routinely sell box heaters for projects in the traditionally warm southern states of Texas, Louisiana, Mississippi, Alabama, Georgia, and on occasion in Florida. Mother Nature can surprise us: even Florida and Nevada can freeze. This blog post about backflow cages goes into more detail.

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What types of heaters are available and how do they work?

Wall Heaters

Most backflow cover heaters in the industry are wall mounted. This method is simply unable to deliver the same amount of freeze protection provided by a floor or slab-mounted heater. Because of the door configuration, wall heaters must be mounted to one side. And because they do not meet the wet/damp requirement, they must be mounted at a minimum of 12” off the slab. Remember that heated air always dissipates straight up, so these heaters’ warmth channels straight out of the top of the enclosure long before uniform warmth is achieved.

 

Slab Mounted Heaters

On the other hand, a slab mounted backflow cover heater provides heat to both the internal equipment as well as the up to 16 inches down into the riser pipes beneath the slab. These  heaters will maintain an interior temperature of 40° with an outside temperature of as low as  –30° as is needed to meet ASSE 1060 requirements. Safe-T-Cover’s patented slab mounted heaters are certified for wet/damp conditions. This is obviously necessary for waterworks equipment and really any enclosure that is not watertight. This unduplicated, rugged design has proven reliable for backflow preventer protection in severe environments for years. 

 

Heat Wrap Cable

We do offer a self-regulating heat cable. This heater type is wrapped around the backflow device. However, most enclosure manufacturers only provide the heat cable option for small diameter pipes only.

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How much heat do I need and what voltages are available?

Safe-T-Cover offers the 1000 watt and 2000 watt slab mounted box heaters at 120V and 240V as well. You should set the thermostat for wall mounted and slab mounted heaters at 40 degrees and the heater will maintain this temperature all the way down to –30º degrees F. Safe-T-Cover has sold heated enclosures for many years in Canada and in upstate NY where winters can be long and the temperatures are well below freezing for many days at a time. For more information, you can read our case study from St. John's, Newfoundland about how well aluminum enclosures perform in harsh environments.

alert-icon
What happens if the power fails?

Be Prepared is the Boy Scout motto, and Safe-T-Cover also advocates being in a state of readiness. The first and foremost way to prepare against freezing pipes is to know the power has failed at the enclosure. We offer three different power and temperature failure alarms. There are simpler models with a light and alarm, and systems with remote monitoring and cell phone alerts. The second way you can be prepared is to have a plan in place to provide some type of box heating for the enclosure if it looks like the power might be out for an extended period of time and the temperatures will be below freezing while the power is out. A 9,000 BTU portable propane heater will more than replace the output of a 2,000 watt electric heater.

temperature-icon
How is temperature controlled? Where is the thermostat installed?

For smaller diameter pipe sizes, most manufacturers provide a self-regulating heat cable. This video from Instrument Specialties Inc. gives an overview of how these heating cables work. For the other two heating options, the wall mounted and slab mounted enclosure heaters, a thermostat determines when the heater will be energized. Most wall mounted heater thermostats are built into the body of the heater and are located high enough on the wall for the heater to be safe from water damage. For slab mounted heaters, the thermostat is installed about 12” above the slab. The thermostat is set at 40 degrees and are designed to maintain this temperature inside the enclosure all the way down to – 30 degrees F. That is, if the box heater satisfies the ASSE 1060 class 1 requirements.

HEATERS WE OFFER

Model Number

Mount

Voltage

Wattage

BTUH

Phase

Amps

Length (in.)

Spec

Submittal

Assembly Instructions

List Price Sheet

Chromalox-30 Cable 120 90 0 Single 0.75 216.00 specification submittal instructions $132.00
HCH2000-120 Slab 120 2000 6824 Single 16.66 37.00 specification submittal instructions Not Sold Separately
HCH2000-240 Slab 240 2000 6824 Single 8.33 37.00 specification submittal instructions Not Sold Separately
HCHS1000-120 Slab 120 1000 3413 Single 8.33 23.00 specification submittal instructions Not Sold Separately
HCHS1000-240 Slab 240 1000 3413 Single 4.16 23.00 specification submittal instructions Not Sold Separately
HCHS500-120 Slab 120 500 1707 Single 4.16 23.00 specification submittal instructions Not Sold Separately
Chromalox-HVT-2411W Wall 120 2000 6824 Single 16.66 28.00 specification submittal instructions $918.00
King-U12100-SS Wall 120 1000 3412 Single 8.33 17.00 specification submittal instructions $669.00
 

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