Topvex TR800, TR1300, TR1800, TR4000
Operation and Maintenance Instructions
Systemair Inc.
24
4.5 Cooling Recovery
If the extract air is colder than the outdoor air and cooling is required, the heat exchanger control is
reversed in order to return the cool extract air.
Note
The following is only valid if the cooling recovery function is set to
Active
in the program menu.
4.6 Exchanger Frost Prevention
If the exhaust air temperature falls below the frost threshold of the unit the exchanger frost prevention
function will be triggered and the unit will cycle between ventilation mode and the selected type of frost
prevention mode in order to prevent any frost build up within the unit.
Types of frost prevention mode:
Exhaust only:
During exhaust only frost prevention, the supply fan will shut down and the outdoor air damper will close
(interruption of the cold outdoor airflow). The unit will keep extracting warm air for a defined period of time
preventing any frost build up before going back to normal ventilation mode.
Recirculation:
There are 3 different recirculation configurations. First is a 5th port configuration with continuous exhaust
set to
“NO”
. Second is a 5th port configuration with continuous exhaust set to
“YES”
in order to maintain
an uninterrupted rate of exhaust. The last option is an H-Type configuration where the unit exhaust air is
recirculated through the supply stream (continuous exhaust has to be set to
“NO”
for this configuration).
These configurations require a dedicated recirculation damper interlocked with the outdoor air damper in
order that as the outdoor air damper closes, the recirculation path is opened and vice versa.
During recirculation frost prevention, the outdoor air damper will close and the dedicated recirculation
damper will open. The unit will recirculate warm air for a defined period of time preventing any frost build up
before going back to normal ventilation mode.
Note
The following is only valid if the exchanger frost prevention function is set to
Active
in the program menu.