Extractor fan bathroom

[tellytv]

I'm looking at getting a extractor fan for the bathroom,

room isn't very big

431cm Length
152cm Width
228cm Height

I've tried to work out what size fan I need for the room and I seem to make it 152m3/hr

is that correct? as most extractor fans I've been looking are 97m3/hr

any help would be appreciated

thanks

 

[JohnW2]

431cm Length ... 152cm Width ... 228cm Height
I've tried to work out what size fan I need for the room and I seem to make it 152m3/hr ... is that correct? as most extractor fans I've been looking are 97m3/hr

With those dimensions, I make the room about 14.94m³ - so 152m³/hr would be just over 10 air changes per hour - is that what you were aiming for?

Kind Regards, John

 

[tellytv]

Thanks for the reply

To be honest I don't understand it

is 10 air changes per hour about right for a bathroom?

 

[JohnW2]

Thanks for the reply To be honest I don't understand it

Fair enough - but how did you arrive at the 152m³/hr?

is 10 air changes per hour about right for a bathroom?

I don't know, but someone here probably will - it sounds pretty high to me. I seem to recall a minimum figure of 15 litres/second (54m³/hr) for bathrooms (when mechanical ventilation is required by regulations), but I may have dreamed that!

Kind Regards, John

 

[tellytv]

I used a calculator online and put the measurements in, but thought it was a bit high.

 

[ban-all-sheds]

I don't know, but someone here probably will - it sounds pretty high to me. I seem to recall a minimum figure of 15 litres/second (54m³/hr) for bathrooms (when mechanical ventilation is required by regulations), but I may have dreamed that!

You can't have to much (short of doors being pulled open, animals and small children being pinned to the grille, etc).

You can have too little though.

As with many things in life, the minimum performance required by the regulations is pathetically inadequate.

Also the calculators do not (or rarely) allow for ducting and vent etc losses.

 

[JohnW2]

I don't know, but someone here probably will - it sounds pretty high to me. I seem to recall a minimum figure of 15 litres/second (54m³/hr) for bathrooms (when mechanical ventilation is required by regulations), but I may have dreamed that!

You can't have to much (short of doors being pulled open, animals and small children being pinned to the grille, etc).

I suppose so (from the ventilation POV) - but I personally wouldn't be too amused if my house-full of expensively-heated air was sucked out and replaced by cold wintery air from outside every few minutes!

... so what is your advice to the OP as regards extraction rate? Do you think that the 152m³/hr that he calculated is really what he needs?

Kind Regards, John

 

[ban-all-sheds]

I suppose so (from the ventilation POV) - but I personally wouldn't be too amused if my house-full of expensively-heated air was sucked out and replaced by cold wintery air from outside every few minutes!

That's true, but one of the banes of modern housing is insufficient ventilation.

Probably not an intrinsic problem with your leaky old part Victorian, part Georgian house

Proper MVHR is, of course, the answer. Be nice if one could also harvest the water in the air from bathrooms and use it for toilet flushing.

... so what is your advice to the OP as regards extraction rate? Do you think that the 152m³/hr that he calculated is really what he needs?

I'm not an expert.

My bathroom is 10.5m³ and come the next revamp I'm planning to install a fan with a raw performance of 500m³/hr...

 

[JohnW2]

I suppose so (from the ventilation POV) - but I personally wouldn't be too amused if my house-full of expensively-heated air was sucked out and replaced by cold wintery air from outside every few minutes!

That's true, but one of the banes of modern housing is insufficient ventilation.

Very true - but when you said that "you can't have too much" (extraction) I presumed that you were talking about a situation in which there was enough ventilation to allow a large amount of extraction to actually 'work'.

Probably not an intrinsic problem with your leaky old part Victorian, part Georgian house

In some senses unfortunately, not a problem at all!!

... so what is your advice to the OP as regards extraction rate? Do you think that the 152m³/hr that he calculated is really what he needs?

I'm not an expert. ... My bathroom is 10.5m³ and come the next revamp I'm planning to install a fan with a raw performance of 500m³/hr...

Goodness! Is your house ventilated/draughty enough to enable you to get anything approaching that throughput of air? ... and, returning to my initial comment, roughly what is the volume of your entire house (i.e. how many 'house changes per hour' would you be talking about?!

Kind Regards, John

 

[tellytv]

I've thinking about getting the "Designer Metal 125mm 5" dia 12v SELV" on fantronix.com


However it says "Low voltage 12v Transformer"

Would this be ok or not?