Advise need for fans

[leebut]

hello guys


I’m after some advice please I’ve been asked to carry out some work in a children’s nursery, the scenario is as follows:-

The nursery has a kitchen which is located in a cellar (which has no window) of a large detached property, they are having a revamp of the kitchen over Christmas period, the problem I’m faced with is they’ve asked for a 6” extractor fan to extract steam etc so will be ok to catch some grease but not loads and the other part which I can’t find anything on is they want a fan to draw fresh air in from outside to recirculate and cool the kitchen, has anyone had experience of this and what did you use??


Regards



Lee

 

[leebut]

Yes @SparkyChick

If supply and extract fans are used then they need balancing correctly so they don't create air pressure problems eg positive air pressure pushing kitchen doors open etc.

Numerous ways to do it depending on what level of kit is installed.

Yplan

The kitchen has a fire door with a spring closer so there’s little chance the door could be blown open with the fan

You need to carefully consider where the ductwork is going to be routed. In the event of a fire there could be transfer through the ductwork and hence fire dampers may be required.

The plan was to be a sleave though the exterior wall on one wall with the drawing fan and sleeve through the other exterior wall (90 degree to the draw fan wall) with the extraction fan

 

[Devonchris]

You need to carefully consider where the ductwork is going to be routed. In the event of a fire there could be transfer through the ductwork and hence fire dampers may be required.

The input, fresh air, side may also need to be linked to the fire alarm. You don't want to be "fanning" the flames.

 

[westward10]

The input, fresh air, side may also need to be linked to the fire alarm. You don't want to be "fanning" the flames.

It is not so much fanning the flames but also if a fire damper is used the supply fan can build up pressure in the room which could force smoke out onto the escape route.

 

[leebut]

The latest update on this fan requirements is, the room is approximately five metres long by three metres wide and two and a half metres high there’s going to be an 150mm ducting through the outside wall direct to open air on both the draw and extraction sides, the customer has asked for a humidistat on the extraction side and both fans are to be controlled via the kitchen lighting circuit as there’s no window to gain light.

The property has fire doors with spring closers to all rooms that are closed at all times, I've spoken to edmunsons Electrical who have spoke to monsoon and vent axia both are non commital so looking for practical advise off any of you guys who have experienced this before


Cheers


Lee

 

[AJshep]

Have a read..

https://www.members.labc.co.uk/site...ventilation_compliance_guide_2010_edition.pdf

 

[Devonchris]

The building regs, including part F, only applies to new builds or substantial alterations. I wouldn't think a kitchen revamp would be defined as substantial or that building control are involved in this. However, assuming that you won't have to comply, part F does provide some useful information on what you might wish to achieve.

I believe that the problem you are trying to overcome is excessive heat, and possibly condensation, build up in a kitchen with no natural ventilation and the obvious solution is a good extractor hood over the cooker range. I think a humidistat is a distraction and not necessary as with a cooker hood most of the problem will be dealt with at the source. Providing it's used of course.

Replacing the air being extracted, particularly with fire doors fitted, is not so simply. Cold damp air pumped into that environment, which would be most of the time in this country, would only add to the condensation problem and the obvious solution would be an integrated combined system with a heat exchanger unit, as mentioned by others. However I suspect this would not be suitable or within budget.

So my solution would be a commercial grade cooker hood and extractor with an additional reversible extractor on the opposite wall. This would provide flexibility in being able to boost the extraction rate or provide colder air into the kitchen.

You might also suggest the revamp includes induction cooking as this will do away with most of the wasted heat that results from other forms of cooking.

Good luck.