THA/THF Roof Terminals


EXHAUSTO roof terminal THA is designed for air exhausts and THF is designed for outdoor air intakes for mechanical ventilation systems.

Their design ensures a good technical solution with minimal pressure drop.

NB: THA/THF do not satisfy Fire Standard DS428, which requires 50 mm of insulation in the roof penetration.

Technical description

THA/THF Technical description

External scroll Hot-galvanised sheet, black lacquer RAL7021
Insulation  5 mm polyethylene foam (to prevent condensation)
Support fixture A support fixture for fixing under flashing is available for extra payment.
Warranty is void If the support fixture is not used in accordance with the instructions.


Without flashing Where roof terminals are supplied unpainted
PERFORM Standard black PERFORM
Grey and red are available on extra payment
Zinc Used for mounting under roofing felt



The THF roof terminal is for outdoor air intakes with a round inlet, giving minimal pressure drop. It has an integral bird net.

THF 250



The THA roof terminal is for exhaust air. The large free space ensures a low pressure drop, even where air volumes are large. It has an integral bird net.

THA 250


Dimensional drawing

THA/THF Dimensions table

Dimensions E, F and G apply only to PERFORM flashing.
With zinc, the flashing is always 100 mm.

PERFORM flashing can cater for +/- 2.5° relative to the given roof pitch.

A dimension varies according to degree dimension. C = adapter size.

THA THF målskitse

L1 mm H mm C mm C2 mm Weight, kg
0-35° 36-60° 
THA160 707 892 160 Ø160 Ø280 5
THA200 762 987 160 Ø200 Ø350 7
THA250 869 1144 190 Ø250 Ø440 9
THA315 995 1337 220 Ø315 Ø550 13
THA400 1172 1422*** 250 dia. 400 Ø680 23
THA500 1208* 1458** 290 dia. 500 Ø850 30
THF160 732 917 160 Ø160 Ø280 5
THF200 787 917 160 Ø200 Ø350 7
THF250 894 1169 190 Ø250 Ø440 9
THF315 1020 1369 220 Ø315 Ø550 13
THF400 1197 1447*** 250 dia. 400 Ø680 23
THF500 1233* 1483** 290 dia. 500 Ø850 30

*0-30° **31-50° *** max 50°

Angle v E F G
0° < v ≤ 2° 100 100 100
2° < v ≤ 60° 250 300 250
Pressure drop

THA/THF Pressure drop

THA - Exhaust air

THA trykfald

Pt = total pressure drop
Temperature: t = 20°C
Density ℓ = 1.2 kg/m3

THF - Outdoor air intake

THF trykfald

Pt = total pressure drop
Temperature: t = 20°C
Density ℓ = 1.2 kg/m3

Flue gas resistance

THA/THF Flue gas resistance

If the duct system has smoke ventilation, e.g. in apartment buildings, flue gas resistance in the duct system must be calculated from the following diagram.

The diagram shows smoke gas resistance.

THA THF røggasmodstand

Pt = total pressure drop at smoke gas resistance
Temperature: t = 20°C
Density ℓ = 1.2 kg/m3


Add all about the product series THA/THF Roof Terminals


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