Permanent trickle ventilation

Permanent ventilation is provided by means of spacer washers inserted in the Thermadome rooflight fixings. A gap of 5–10 mm can be provided around the complete perimeter, without compromising the security or weather protection of the rooflight.

Controlled trickle ventilation

Trickle ventilators can be factory fitted to the top of Therma-kerb PVC 150 and 300 mm or PVC opening frames. The vents are fitted to two sides as standard and will provide background ventilation of 8000 mm2 to satisfy the requirements of Building Regulations.

Controlled louvre ventilation

A vent collar unit fitted with adjustable louvres is located between the rooflight dome and the builders kerb. Units are available as a 100 mm high aluminium collar with white foamed PVCu insulating lining internally or a 150mm high white multichambered PVCu collar. The vents are fitted to two opposite sides as standard. All four sides of the rooflight may be fitted with vents, if higher levels of airflow are required. For Alu-kerbs, Alu-kerb adaptors and Therma-kerbs 300 mm high, the vents and cowls are fitted directly in the side wall. The fully adjustable louvre vents are operated by means of a hooked rod, available in lengths of 1.5, 2 or 3 m. The louvres are protected from the elements by an external weather cowl.

Powered ventilation

Where natural ventilation is insufficient,  Thermadome rooflights can be supplied with Vent Axia Solo centrifugal extract fans. These are mounted in the side wall of Therma-kerb PVC-u 150/v or Therma-kerb PVC-u 300/s. These high performance extract fans are specifically designed for ventilating internal bathrooms, WC's and other small rooms. They have an extract performance of 85 m3/hr (24 l/s) and can be fitted in one or more sides. Where greater air movement is required, white PVC lined fan collars with pre-cut apertures are available to enable fitting of larger axial fans (eg Vent-Axia T-series).

Opening ventilation

Where maximum natural air movement is required, Thermadome rooflights can be supplied fitted with hinged opening frames, with a manual spindle operated by a winding rod (or electric motor for remote control). Where the hinged side exceeds 1.3 m a tandem spindle unit is fitted. Frames are constructed from PVC-u, for use when fitted to Therma-kerb or Alu-kerb upstands. Alternatively, where mounting directly to a builder’s kerb, an aluminium frame is supplied. Electric motors can be supplied complete with open/close switches (wiring by others) and can be specified to open up to 600 mm, both options are an extra cost option. Insect screens are available in most sizes when supplied with Therma-kerbs or Alukerb upstands and manual opening frames.

If you would like assistance at any time about any of the rooflights or would like further details of our range, then please do not hesitate to contact us on 01276 451555, e-mail us at info@nationaldomes.com or use this e-mail form to contact us.