Scenario

This case involves a care home with a water loop heat pump system. Heat pumps throughout the facility provide zone heating and cooling. If external heat is required to heat the water loop, a boiler injects hot water into the loop. If the loop needs cooling, loop water is pumped through one side of a plate and frame heat exchanger, while cold water from an underground well is pumped through alternate plates of the plate and frame heat exchanger.

Evidence

Persistent high gas usage was noticed.

Problem

The local gas utility was brought in to investigate the problem and discovered that manual valves had inadvertently been set incorrectly, allowing a continuous flow of cold water from the well into the heat exchanger. Since the loop temperature was below the set-point, the boiler constantly added heat to the loop. Therefore, gas was wasted as the boiler effectively transferred its heat into the aquifer.

Cost

The problem persisted for 10 months, wasting 1,575 GJ of gas costing $16,705.

Prevention

The facility profile provided by Arctic Fox Energy Tracking would have allowed staff to clearly see the 620% increase in gas usage in one month despite a drop in degree-day heating demand, permitting immediate corrective action.