Universal Electronics 975 Programmable Cool Fan-Onand Fan-Offdelay, Installation, Heating

COOLING is from 9 to 40. The factory preset is 14. The recom- mended initial setting for hydronic systems is 35.

The cooling will not go below 9 because compressors require a longer cycle.

The chart below shows how this adjustment range affects thermostat performance.

PROGRAMMABLE COOL FAN-ON AND FAN-OFF DELAY

This option allows a selection of a fan-on delay of 1 to 5 seconds on a call for cool and 1 to 127 seconds of fan-off delay after the thermostat has satisfied the call for cool.

A short delay to allow the A-coil to cool off before the fan turns on may

be preferred. This also allows the compressor and the fan to come on at slightly different times, which allows full power to the compressor on start up.

The fan off delay allows the fan to continue running after the compres- sor has shut off. This distributes the cooling that would otherwise stay trapped in the air conditioning coils through the ducts. Ideally the timing

		HEATING			COOLING
Anticipation Value	Cycle Length		Differential Temperature	Cycle Length		Differential Temperature
2–8	Shorter		0.4–0.6 F (0.2–0.3 C)	N/A		N/A
9–20	Longer		0.6–1.0 F (0.3–0.6 C)	Shorter		0.6–1.0 F (0.3–0.6 C)
21–40	Hydronic		1.0–1.6 F (0.6–0.9 C)	Longer		1.0–1.6 F (0.6–0.9 C)

These numbers are approximate and represent operation with a typical system. Actual temperature differentials and run times may vary widely based on your building and equipment, as well as outdoor temperature conditions.

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Installation