"Recirc" Mode

The ventilation system automatically functions in "Recirc" mode whenever the Pool Hall environment is within the set points of the Humidistat and Room Thermostat.  In "Recirc" mode the Room Thermostat maintains air temperature relatively close to the thermostat set point, which should be 1 or 2 deg C above the water temperature,to minimise condensation.  An automatic timer may override the "Recirc" mode to ensure the Heat Exchanger does not operate  in "Recirc" mode for long periods.  Its purpose is to switch the system to Heat  Exchange mode at regular intervals, regardless of other conditions to ensure Indoor Air Quality is maintained (i.e. free of chlorine odour and low in humidity).

"Heat Exchange" Mode

When Humidity exceeds the Humidistat set point, the "Recirc Damper closes and the ventilation system operates in the "Heat Exchange" mode.  In this mode, temperature control is transferred to a three stage Air Off Thermostat which tops up the temperature of the fresh air after it has passed through the Heat Exchanger.  This thermostat senses and controls the temperature of the air entering the Pool Hall.   When indoor humidity falls below the Humidistat set point, the Recirc Damper automatically reverts to "Recirc" mode.

"Summer By-pass" Mode

If the Pool Hall air temperature exceeds the set point of the Room Thermostat by, say, 3 - 4 deg C (due to solar gain on a hot summers day), the Summer By-pass Thermostat automatically opens the Summer By-pass damper.  This causes exhaust air to by-pass the heat exchanger and prevents heat recovery from "over heating" the Pool Hall.   When the Pool Hall temperature falls to within 1 - 2 deg C of the Room Thermostat set point (i.e. after the heat of a hot summers day has reduced) the Summer By-pass damper automatically closes and the ventilation system reverts to the "Recirc" mode.