GENERAL INFORMATION
HCV & HCVR Evaporative Cooling & Gas Heating
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AIRA HCV/R series heater/cooler units are an indirect fired gas warm air heater with an evaporative cooler
section attached. This unit can be used in closed in areas such as offices, shops, restaurants, schools,
Take-away food stores, glasshouses etc. HCV/R units can be wired up to suit site condition requirements
and options. These options include: Single or two speed motors, duct louvers, electronic modulating gas
trains, return air, etc.
The heating section usually consists of a stainless steel indirect fired heat exchanger, RAM - 5EM7-01 flame
controller, electronic ignition, high limit switches and pre and post heat switches. A room thermostat is
connected to read heat requirement in the application. As the temperature in the room and the thermostat
set position get closer the gas valve modulates. There are many different options available to ensure
suitability of the equipment to suit a particular site.
Evaporative cooling is via Celpad water saturated pads. This type of pad has more stability, longer life and
airflow as compared to older aspen style pads and less maintenance is required. A Variety of covers can
be provided including marine grade louvre protection, fire screens, insect screens and filters.
Ventilation is achieved by simply turning the fan on without the water pump running. This mode of
operation is used when ambient temperature can be utilised to cool down or heat up the work area. I.e. if
the work area is has machinery that is generating heat above 22°c and the ambient temperature is 18°C
with high humidity the ventilation mode can be selected.
With a Return air function installed, gas consumption is reduced. Supply air is heated and then returned
through the heat exchanger to be reheated. If the heater is fitted with a modulating gas train, the burner
will modulate down to low fire and then turn off when the room thermostat reaches the pre selected
temperature. When the unit is operating in return air mode, fresh air is still fed into the heated area at a
lower rate to ensure air remains fresh.
As the AIRA/HCV/R is indirectly fired the flue gasses must be flued to the atmosphere. The flues must be
clear of any air intakes, eaves etc. as per Australian gas regulations. The efficiency of a heat exchanger
unit is approximately 80%.
Commissioning is to be done by an experienced 'A' Type approved service person and does not normally
require an inspection by the Office of Gas Safety (OGS).
Control of the Unit can be via a number of methods. The standard controller is a 5 gang wall mount switch
allowing the unit to operate in high cool/low cool/ventilation/heat modes. Some people find a rotary dial
easier to operate. The unit can also be controlled via push button control or via Building management
system (BMS) or Variable speed drive (VSD). Controls are not designed to switch quickly between heating
cooling and ventilating but graduate temperature toward desired outcome. Please contact Factory for
clarification re control wiring.
VSD
Push Button
Rotary Dial
5 Switch
