400895 Topvex FR Operation and Maintenance Instructions

Topvex FR800, FR1600, FR3800 Operation and Maintenance Instructions

Systemair Inc.

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airow).Theunitwillkeepextractingwarmairforadenedperiodoftime

preventing any frost build up before going back to normal ventilation mode.

Recirculation:

Thereare3differentrecirculationcongurations.Firstisa5thportcongurationwithcontinuousexhaust

set to “NO”.Secondisa5thportcongurationwithcontinuousexhaustsetto“YES” in order to maintain

anuninterruptedrateofexhaust.ThelastoptionisanH-Typecongurationwheretheunitexhaustairis

recirculated through the supply stream (continuous exhaust has to be set to “NO” forthisconguration).

Thesecongurations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dened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.