E – Sequence of Operation
E‐
2
Heat Recovery Option.
Dehumidifiers, packaged with Minimum Exhaust Fan and Minimum Outdoor Air damper, could also have
additional
Heat Recovery
(HR) closed‐loop glycol system.
Heat Recovery
loop (see Pic. E.1 below) consists of two coils (air‐to‐glycol heat exchangers) and a pump,
establishing glycol circulation between them. One coil, installed at exhaust air opening, recovers portion of
exhausted air energy, another coil, installed at outdoor air intake, transfers this captured energy to entering
outdoor air.
Space Heating
When premise air temperature drops below the set point, the dehumidifier control system issues a call for Space
Heating Mode and engages space heater (electric heater, hot water coil with valve, gas boiler etc.) by sending space
heating signal, respective to space heater control type ‐ on/off, variable (0‐10VDC), etc.
Air Conditioning, Dehumidification and Pool Heating.
When premise air temperature goes over (exceeds) its set point, the dehumidifier control system issues a call for
Air Conditioning Mode. Respectively, when premise air humidity goes over (exceeds) its set point, the dehumidifier
control system issues a call for Dehumidification Mode. In some instances, these calls may co‐exist.
To execute Dehumidification or Air Conditioning (Cooling) mode, control system, depending on current conditions,
would resort to available means of cooling or dehumidification.
Economiser Mode Option.
Note.
Economiser Mode requires dehumidifier to be equipped with full (min and additional) exhaust and
outdoor air options!
If outdoor air is dry and/or cool, it could be used to dehumidify and/or cool the premise. In this case, on call for
Dehumidification or Air Conditioning mode(s), control system would simply increase exhaust fan(s) speed signal to
direct more stale return air outside and bring in more outdoor (dry/cool) air in, thus reducing supply air humidity
and/or temperature (as needed).
Pic. E.1
