Engineers and property owners alike want assurance that the water equipment inside their aluminum enclosures will not be subject to freezing. This is especially a concern for people in the northern United States and Canada, but after significant freeze events in recent years throughout the southern US, is now a necessary consideration anywhere in North America.
For proper freeze protection, you should be using a heated enclosure that meets the ASSE 1060 Class I standard. This means the heated enclosure was built to maintain a temperature inside the enclosure of at least 40°F when the outside temperature is as low as -30°F. By choosing a Class I enclosure, you'll know your equipment is protected against freezing under normal and most extreme operating conditions.
What happens if the valve or pump heater fails? What happens if the heater loses power? Fortunately, there are multiple monitoring options to ensure the equipment inside your enclosure stays at the correct temperature and operational integrity is maintained. The various monitors on the market include ones which provide a strobe light and audible alarm, and ones which alert the equipment owner via phone, push notification or email.
Below is an overview and comparison of some available monitoring and alert options.
Valve and Pump Heater Monitoring System Options
TAPF (Temperature Alarm Power Failure)
Safe-T-Cover has an off-the-shelf TAPF system that will alert you whenever the inside temperature drops below a predefined threshold. That set point is determined by the customer, and typically is set at 38-40°F. It also triggers an alert if there is a power failure on the electrical circuit supplying the heater. The TAPF has both a visible strobe light signal and an audible alarm. The TAPF monitor also has an extra set of contacts, so that an alarm signal can be run into a nearby control room. It also has a DC charger that will power the strobe and audible alarm in the event of a power failure. Typically, this DC battery will power alarms for up to 10 hours.
Hubbell
Hubbell® carries alarm systems very similar to the Safe-T-Cover TAPF. The Hubbell alarms are triggered whenever there is a power failure and/or the inside temperature drops below an established set point. Hubbell has a total of five different alarm options which feature either a strobe light, an audible alarm or both.
Supco TA-2 Alarm
AquaSHIELD® resells a simple alarm system provided by Supco®. The Supco TA-2 alarm is an inexpensive audible alarm that was initially developed for refrigerator and freezer applications, but is also suitable for heated enclosures. The Supco TA-2 alarm does not work in the event of a power failure, because it lacks a DC battery.
Sensaphone Call Out Alarms
Safe-T-Cover also offers the Sensaphone® alarm. This alarm will automatically dial telephone numbers of established contacts whenever the temperature drops below a chosen set point or in the event of power loss. Up to eight people can be called in sequential order in the event of an alarm. You can even customize the alert message, much like setting up your voicemail. Sensaphone models also include a backup battery in the event of a power failure. Data can also be accessed via a smartphone in real-time.
The Sensaphone 1400 Monitoring System calls out through a landline and you can set up to four voice messages that will go out in case of a temperature drop. The Sensaphone Sentinel model uses a cellular modem and you can set up an unlimited number of email, text and phone calls to go out in case of a problem. The Sensaphone alarms can also tap into any existing SCADA system being used to monitor other valves and pumps within the system. You'll want to use the cellular Sentinel model if your heated enclosure is in a remote location. At last check, there is an annual cellular fee associated with the Sentinel model.
Be Prepared for Power Failure
Part of keeping your equipment safe is having a plan in place if the power fails or the interior temperature of your heated enclosure suddenly drops. These alarms will alert you in these cases and it is up to you to decide the best way for you or your team to be notified. If there is someone on site at all times, a strobe and audible alarm may suffice. However, if your equipment is in a remote location, or there are long time gaps where there is no one on location, then one of the Sensaphone style models may work best for you.
No matter what you choose as your alarm system, you'll also need to have a plan ready in case trouble does arise and you need an alternative source of heat. One possibility to consider is to have a 9,000 BTU portable propane heater on standby.
