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Gas Submetering for Existing Construction

Compugas Energy Sentinel


The Energy Sentinel is the primary component of the Compugas system. It records furnace runtime and transmits its data via radio to a central data collection unit once every twenty minutes. If a furnace cycle ends with a partial minute, that data is stored in the Energy Sentinel’s flash memory, and the next furnace cycle begins timing where the previous left off, thereby losing no runtime on partially-completed furnace cycles. Competing systems generally have no electronic memory, and partial minutes are discarded at the end of each cycle, substantially impacting accurate time measurement.


The Energy Sentinel’s exclusive multi-color LED also provides an instantaneous indication of proper connection to its associated furnace. If a problem is detected, the normally green LED turns red within 7 seconds. When proper operation is restored, the green color returns automatically. A quick glance verifies proper connection, furnace operation and energy monitoring functionality.


Designed for future furnace upgrades, Energy Sentinel includes automatic pre-burn purge/prove cycle delays. Future furnace replacements with electronic-ignition devices will be instantly compatible with the existing Energy Sentinel. A single button press by maintenance personnel sets electronic-ignition burn-delay compensation.Frequency-hopping RF signal transmitters to transmit collected consumption data to a centrally-located data collector.


Energy Sentinel’s timing precision is easily verified. At precise sixty-second intervals, the unit’s multicolored LED pulses orange. Whether serving as a quick maintenance check or to appease a concerned renter, the orange pulse can be readily compared with a watch or clock to demonstrate absolutely precise timing.

Photo of an energy sentinel device

Frequency-hopping, spread spectrum RF (radio frequency) wireless furnace runtime monitors are installed in every apartment. This equipment is used to monitor utility consumption in over two million apartments nationwide. Automated nightly data collection is provided using either a dial-up modem or an internet connection.

RF Technology

Consumption data is uploaded daily from your property's onsite data collector to our centrally-located billing facility in Omaha, Nebraska. At the end of each monthly period, a statement that looks like an ordinary utility bill is prepared by Invoice America and mailed directly to apartment residents.

Invoice America Services

Man sitting at table reviewing utility bills

Over 40 years experience specializing in multifamily utility cost allocations.

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