Please call our helpful sales team on 01799 528528 for up to date prices on the products below.

PosiMaster - for condensation control

PosiMaster-Roof Dryair for Houses & Bungalows
Combi Dryair

Order Code: POS240HR

Fresh, dry, filtered air at ambient temperature is introduced continuously into the property diluting and displacing stale, moist air and reducing condensation.

The design includes a digital motor with a pressure sensor that triggers an LED alert should the filter become blocked. An innovative 'Feedback' control ensures the system continues to operate at 100% efficiency until the filter becomes 70% clogged.

Key Features And Benefits

  • Simple to install & inexpensive to run
  • DC motor for quiet operation
  • Diffusers designed to minimise draughts
  • Air temperature cut out when incoming air temperature exceeds 25oC
  • Pre heat can be manually selected
  • Very Quiet
  • Electronic feedback to the motor ensures constant flow rate
  • Electronic controller automatically monitors temperature of introduced air and activates pre heat to maintain comfort levels. If the heater switch is enabled by the user the heater will switch on when the air temperature falls below 12oC
  • BRE Digest 390 compliant
  • Solid state electronics with high efficiency switching power supply
  • Blocked filter indication light


Large capacity, non-woven type processed to labyrinth structure ensuring good air distribution. The synthetic fibres are resistant to moisture, fungi, bacteria and frost. Model VNF250. Heat resistance <100oC. Flammability - self-extinguishing to DIN 53438 F1.


The PosiMaster-Roof Dryair unit is fitted in the roof void and ducted via an air diffuser, normally mounted in the ceiling above a stairwell. All units are fitted with a pre heat facility and the heater control switch is sited on the landing wall at a convenient height to enable the user to switch the heater on or off. Also, the fan speed control is set from this position.

Motor Supply Volume:

Speed Setting Loft Wattage Cost/Year*
Air Flow Litres / Sec Based on 2014 Fuel Costs
Trickle 1 36 7.5 £9.18
Medium 2 42 9.5 £11.62
High 3 48 13 £15.90
Boost 4 63 17 £20.80
dB(A) 32

*These prices are based on the units working 24/7, running on Medium 365 days a year. A typical winter when the Pre Heat is activated will cost approx. a further 8 pence per hour due to a 500 Watt heater. The heater can be turned off by the user, but the fan still runs maintaining a positive pressure.

Fan Dimensions

Unit Casing (mm) 342 x 315 x 280
Unit diffuser ceiling hole Dia. (mm) 200

Electrical Voltage

220/240V AC - 5 amp fuse required via fused spur

Get Help or Advice!

The Condensation Shop offers a wide range of products to suit numerous condensation and damp related issues.

If you would like assistance in selecting the correct product for your specific problem please call our helpful Sales Team on 01799 528528, during normal opening hours.