Installation Manual

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Section G: Δ T Hours (Relative Energy Usage)

Section G1

ΔT Hours

Section G1: Δ T Hours

The control records the temperature difference (Δ T) multiplied by the number of hours the control is in the Melt or Idle modes. This

allows the user to estimate the amount of energy used by the snow melt system. The energy consumption can be estimated by

multiplying the Δ T Hours by the system flow rate (in US GPM) and by the constant K shown below. Note: K values are calculated

averages for most ethylene glycol solutions at 50°F (10°C). K increases with higher temperatures.

% Glycol by Weight Freezing Point K (°F x hr) K (°C x hr)

0 32°F (0°C) 500 900

10 25°F (-4°C) 496 893

20 15°F (-9°C) 487 877

30 3°F (-16°C) 477 857

40 -13°F (-25°C) 462 832

50 -35° (-37°C) 439 720

Example: Δ T Hours = 5225°F x hr, System flow = 20 US GPM, Fluid = 40% glycol and 60% water, therefore K= 462.

Energy Usage = 5225 x 20 x 462 = 48,279,000 BTU.

To clear the current Δ T Hours recorded, press the ▲ and ▼ arrow buttons while viewing the Δ T Hours in the MONITOR menu.