FSL-V-ZAB/SEK

Functional description

Decentralised supply and extract air units for room ventilation and for dissipating cooling loads and heat loads.

An EC centrifugal fan takes in the fresh air which then flows through the motorised shut-off damper and the F7 filter.

Once the fresh air has passed the fan, it flows through the heat recovery unit; it is possible to bypass the heat exchanger in order to protect it, or when it is sensible with regard to energy efficiency.

If necessary, the air is heated or cooled by the heat exchanger before it is discharged to the room as a displacement flow.

The extract air first passes a G3 filter (that protects the unit), then flows through the heat recovery unit, the extract air fan and the motorised shut-off damper before it is discharged to the outside as exhaust air.

Automatic switching to secondary air mode (only with an air quality sensor) if the room air quality is sufficient.

The fresh air damper closes, the self-powered secondary air damper opens and the extract air fan is switched off.

The unit always starts in secondary air mode, which is more energy efficient.

Decentralised ventilation units are technically advanced products of high quality; they offer a wide range of configuration options. For specification details regarding your project please contact your nearest TROX branch or subsidiary.

Nomenclature

L_WA [dB(A)]

Sound power level

t_Pr [°C]

Primary air temperature

t_WV [C°]

Water flow temperature – cooling/heating

t_R [C°]

Room temperature

t_AN [C°]

Secondary air intake temperature

Q_Pr [W]

Thermal output – primary air

Q_tot [W]

Thermal output – total

Q_W [W]

Thermal output – water side, cooling/heating

V_Pr [l/s/m³/h]

Primary air volume flow rate

V_W [l/h]

Water flow rate – cooling/heating

V [l/h]

Volume flow rate

∆t_W [K]

Temperature difference – water

∆p_W [kPa]

Water side pressure drop

∆p_t [Pa]

Total pressure drop, air side

∆t_Pr = t_Pr - t_R [K]

Difference between primary air temperature and room temperature

∆t_RWV = t_WV - t_R [K]

Difference between water flow temperature and room temperature

∆t_Wm-Ref [K]

Difference between mean water temperature and reference temperature

Principal dimensions

L_N [mm]

Nominal length

Inducing displacement flow

The supply air is discharged near the external wall and with a medium velocity between 1.0 and 1.5 m/s. Due to the induction effect the supply air velocity is rapidly reduced such that, in cooling mode, the supply air displaces the room air over the entire floor area. The convection from people and other heat sources causes the fresh air from the pool to rise and create comfortable conditions in the occupied zone.

Heat exchanger

The maximum water-side operating pressure for all heat exchangers is 6 bar.

The maximum water flow temperature (heating circuit) for all heat exchangers is 75 °C; if flexible hoses are used, the water flow temperature should not exceed 55 °C. Units for other pressures and temperatures are available on request.

The water flow temperature (cooling circuit) should be at least 16 °C such that it does not permanently fall below the dew point. For units with a condensate drip tray the water flow temperature may be reduced to 15 °C.

Heat exchanger as 2-pipe system

Air-water systems with a 2-pipe heat exchanger may be used for either heating or cooling. In changeover mode it is possible to use all units within a water circuit exclusively for cooling in summer and exclusively for heating in winter.

Heat exchanger as 4-pipe system

Air-water systems with a 4-pipe heat exchanger may be used for both heating and cooling. Depending on the season, i.e. especially in spring and autumn, it may be possible that an office has to be heated in the morning and cooled in the afternoon.