BULK SAVINGS Inc. Vat | ||
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£27.38 | £20.82 |
Free Air: 30cm² Core drill ‘Black Hole' ventilator BM725 Rated Input - Max 13kW (44,000 Btu/h) Size: 127mm (5") diameter ‘Black Hole' cavity liner and extension piece. Tube length from 228mm to 585mm with extension tube supplied. Brown outer cowl white inner grille. Fixed anti-draught baffles. The...
The BLACK HOLE Ventilation range:
‘Black Hole' ventilation products provide the answer to the dangerous practice of ventilators being blocked off by occupiers who are being annoyed by draughts. This makes an important contribution to safety. New tests show that while this works the ventilator may not pass the required amount of air when the appliance is operating. THEREFORE IT IS IMPORTANT THAT A SPILLAGE TEST IS CARRIED OUT AS REQUIRED BY THE BRITISH STANDARD AND CORGI GOOD PRACTICE
The benefits of a ‘Black Hole'
The ‘Black Hole' magic explained As outside wind pressure increases, a normal ventilator lets more air through causing annoying draughts.
Inside the Stadium ‘Black Hole' Ventilator vortices are formed behind the internal blades as the incoming air is forced to change direction. The gap that the air is able to pass through narrows. As wind pressure increases, the vortices grow, so reducing the total air flow, finally tumbling and slowing to a trickle, thereby cutting down annoying draughts.
Stops wind blasting in - the air flow within the duct is slowed down by the change of direction and by the vortices formed, reducing draughts to a minimum.
Stops light showing through - the occupier cannot see through the ventilator and is less likely to be worried that insects and vermin may enter the house through it.
Stops light shining out - night flying insects like moths, crane flies and mosquitoes are not attracted in.
Absorbs outside noise - reduces the penetration of traffic noise. The internal construction works as a sound baffle.
Allows air to be pulled through by the appliance when it is operating.
Safety - with draught and light annoyance problems eliminated, the occupier will not be tempted to block off the vent.
However, when the heating appliance is operating, air is drawn through the vent and actually speeds up within the constricted air flow between the vortices, thus maintaining the correct amount of air into the room or compartment to allow the fuel to burn efficiently and flue gases to escape.
When the appliance is not working, incoming air is reduced to a minimum, even on windy days. The actual physical difference is that of air blown or drawn. The energy of the blown air (wind) is quickly dissipated by the restriction of the internal shape and the vortices, while the drawn air will flow smoothly round the vortices.
BS 5440 Part 2, 2000:
Several changes have been made to update the previous ventilation standard. Three of the main ones are summed up below but as with all new standards they are not retrospective.
1. The previous words ‘Free Air Space' are replaced by ‘Free Area' measured and Effective ‘Free Area' (see point 3).
2. The ‘Free Area' requirement has been increased from 4.5cm2 to 5cm2 per kW above 7kW input rating.
3. Complex and anti-draught ventilators shall be measured by the volume of air that they will pass i.e. the ‘EFFECTIVE FREE AREA' . The ventilator should be marked accordingly.
Product Category | Passive Vent |
Product Type | Black Hole |
Product Group | Passive Ventilators |
Free air (cm²) - Max | 30cm² |
Packaged Weight (Kg) | 1.2 |
Packaged Length (mm) | 365 |
Packaged Width (mm) | 320 |
Packaged Height (mm) | 70 |
Barcode | 5060272545468 |
Barcode - Type | EAN |
Manufacturer Product Code | BM725 |
Quick Search: | QS2851 |
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Is the black hole ventilator available with a black outer cowl?
Hi Max
The manufacturer does not have a black option though another manufacturer may have something compatible or close.
However, the cowls are not a gloss or polished finish and there would be no problem with spraying the dark brown option black, I have done this for a project before and used a spray paint designed for plastic products called (not unsurprisingly) Plasticote available from nearly all DIY outlets.
Hello Malcolm
where best should I locate Black hole vent. It is in my son's bedroom with two outside walls. There is black mold in the corner of the ceiling (along outside walls) and around the windows - double glazed with no trickle vents. (should I get thoese too?) with thanks Louise
Hello Louise
I have this item installed in my living room for a flueless gas fire which I have now got rid of. I would like to stuff the through pipe with something to stop any draughts but i can't get the cover off. There don't appear to be any obvious fastenings. Does it just prise off or what ? I don't want to cause any damage. Any ideas please ?
Hello Ken
Thank you for your question. There are 4 lugs on the side of grille which can be pushed in with a screwdriver to release the grille. If I can help any further please do not hesitate to contact me.
Kind Regards
Anita
Does this vent meet the ventilation requirements for clueless gas fires?I read that these are " 100cm2 additional" -but not certain what that means?
Hello David
What is the inernal vent made of? Can it tollerate high temperature close to an open fire?
Hello Tim
Sir I have a basement flat which suffered a considerable amount of black wet rot which I found under laminate flooring, on the insulation and on the cement floor beneath which had been laid by the previous manager. The basement itself had not been lived in for four years and has double glazing without vents. After lifting the flooring, the cement seems to be drying out and turning grey again. However, the bottom of the internal walls appears to have some dampness. I know that I need more ventilation and am wondering if these black hole vents will help more air move around. The heating is from electric only. Thank you and please feel free to ask me any questions if you need more info. Regards
Hello Stephen
Just bought an old 1898 house and in the lounge, we've got an existing grill over a misshapen approx 120mm deep hole in the external/internal brick wall (no cavity) leading to outside grill. There's a rough gap of 90mm x 150mm. I want to replace it with this vent being 127mm diameter. Do you think I could extend the hole with hammer and chisel to fit part?
Hello Rachel
Hi - can you tell me if this order has been shipped yet? I can’t see the status update in my account. Aoife
Hello Aoife
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