Wall Mounted Exhaust Fans.

[soundman]

In the process of building an enclosed kitchen area at the back of our new house.

Don't know much about fans. Does anybody have an idea of what size I might need to adequately ventilate an area about 6m x 2m.

8", 12" or bigger? The shop says 12" should be fine, but I have my doubts. Any experiences?

Cheers & thanx,

Soundman.

[chownah]

I googled "what size exhaust fan" and found lots of stuff.

This is a good one:

http://www.electricsuppliesonline.com/howtosiexfa.html

It says that intermitten ventilation for a kitchen should be 15 air changes per hour....so calculate the volume of the kitchen and convert to cubic metres per minute or whatever units of air flow are used in the specs for the exhaust fan. The link gives a lot of explanations and different methods.

Also, cheap exhaust fans are noisey. You might want to run some fans in the stores to see how noisey they are. Usually if two fans are rated for the same volume rate of flow then the one with the bigger blades will be quieter.....also if you can find a two speed fan whose high speed meets the requirement you might find that in many/most conditions you will not need full power and you can run it at the lower setting which will be quieter too. Generally speaking, slower moving larger blades are quietest and most efficient.

Chownah

Edited October 6, 2007 by chownah

[soundman]

I googled "what size exhaust fan" and found lots of stuff.

This is a good one:

http://www.electricsuppliesonline.com/howtosiexfa.html

It says that intermitten ventilation for a kitchen should be 15 air changes per hour....so calculate the volume of the kitchen and convert to cubic metres per minute or whatever units of air flow are used in the specs for the exhaust fan. The link gives a lot of explanations and different methods.

Also, cheap exhaust fans are noisey. You might want to run some fans in the stores to see how noisey they are. Usually if two fans are rated for the same volume rate of flow then the one with the bigger blades will be quieter.....also if you can find a two speed fan whose high speed meets the requirement you might find that in many/most conditions you will not need full power and you can run it at the lower setting which will be quieter too. Generally speaking, slower moving larger blades are quietest and most efficient.

Chownah

Thanx for that Chownah. Web link info. quite easy to follow.

Looks like a 12" fan should be adequate. I've seen a Panasonic model that is two way, ie both blows & sucks. Might buy that.

Cheers.

[londonthai]

if your kitchen is enclosed than you will need an air duct to take the air to the side of the building or (to avoid the smell next to your windows) above the roof. Having an air duct above the roof will give you additionally a passive air flow, taking the heat, fumes and moisture out of the kitchen even with the fan switched off. The wider the fan the wider air duct should be.

To avoid the noise it's better to place the fan at the outlet and not on the kitchen wall.

Not sure what the advantage of two way fan would be