Anyone recognise this fan?

[Electric Magic]

Have been to a quote in a block of flats (built in the last 10 years). They want their existing fan replaced as they think it isn't powerful enough (damp patches on the ceiling - its an internal bathroom, no windows). I've not seen this particular fan before and can't tell from looking at it what size duct it goes into (though I suspect its 100mm) and obviously I'd also like to find out the extraction rate. Anyone know what make it is?

 

[marc_v33]

Looks like an enviro vent not sure of the model though

Possibly an
EFHT2S

 

[Electric Magic]

Thanks Marc, that might well be it.

 

[Adam W]

+1 for envirovent. You should be able to get either a replacement which will fit, or change it for a 12v if needs be.
They often have a setting whereby they will automatically adjust the speed according to the humidity, or you can speed the fan up either by means of a pull cord (probably not suitable in this instance) or a remote switch for a set amount of time, if for example the humidity is 'normal' but you need to have a clearout.

 

[Marvo]

What are the dimensions / volume of the bathroom?

 

[ruston]

Also is there a suitable gap under the door etc to let the air flow , or you may well be back.

 

[AJshep]

I woudnt even bother, if its mouldy then your best off getting a CMEV fan "Continuous" fan.

I hate ventilation but i know abit about it, without getting overly technical.
For a normal intermittent (over-run/ humidistat) fan to comply with Part F you need alot of background ventilation, (fine in a single glazed house) when you do the math a standard 3 bedroom house with trickle vents on every window most likley wont comply as you physically cant put enough windows in a property to get enough background ventilation.

Unfortunately nobody seems to know this. New houses are made and no trickle vents installed, flexible ducting everywhere, no undercuts under doors.
Then they wonder why the house stinks and they get moyld up the walls.

Good rule of thumb is as Ruston said, look through ever room check you have 9mm undercuts under each door, then if i were you id put in continuous extract van and be done with it.

I use Greenwood airvac cv2gip but Expelair, and other manufactures do them. I doubt if you have a flow meter but the custom settings on the usually about right.

Another thing worth mentioning, is how is the ducting run ? if its run in a non-insulated area then you could find that you have a bigger problem with condensation dripping off the ducting on to the ceilling. This will continue to happen unless the ducting is insulated.

The firm i used to work had to go and rip down the ceilings in a load of social houses that were less that 2 years old.
Everyone had black ceilings due to unisulated ducting.

Horrible job, i hate ventilation but the company got good money for if.

 

[Electric Magic]

+1 for envirovent. You should be able to get either a replacement which will fit, or change it for a 12v if needs be.
They often have a setting whereby they will automatically adjust the speed according to the humidity, or you can speed the fan up either by means of a pull cord (probably not suitable in this instance) or a remote switch for a set amount of time, if for example the humidity is 'normal' but you need to have a clearout.

Having looked at the instructions I've suggested the customer check what setting it is on before I quote for a replacement as the humidistat activated boost is up to 35 litres per second for the bathroom setting and 60 litres per second for the kitchen setting. That said, I wouldn't be surprised if the issue is due to the ducting run as the bathroom is only about 12m3 so even at 35l/s it should clear in less than 6 minutes

 

[Electric Magic]

What are the dimensions / volume of the bathroom?

About 12m3

 

[Electric Magic]

Also is there a suitable gap under the door etc to let the air flow , or you may well be back.

About 1cm

 

[Electric Magic]

I woudnt even bother, if its mouldy then your best off getting a CMEV fan "Continuous" fan.

I hate ventilation but i know abit about it, without getting overly technical.
For a normal intermittent (over-run/ humidistat) fan to comply with Part F you need alot of background ventilation, (fine in a single glazed house) when you do the math a standard 3 bedroom house with trickle vents on every window most likley wont comply as you physically cant put enough windows in a property to get enough background ventilation.

Unfortunately nobody seems to know this. New houses are made and no trickle vents installed, flexible ducting everywhere, no undercuts under doors.
Then they wonder why the house stinks and they get moyld up the walls.

Good rule of thumb is as Ruston said, look through ever room check you have 9mm undercuts under each door, then if i were you id put in continuous extract van and be done with it.

I use Greenwood airvac cv2gip but Expelair, and other manufactures do them. I doubt if you have a flow meter but the custom settings on the usually about right.

Another thing worth mentioning, is how is the ducting run ? if its run in a non-insulated area then you could find that you have a bigger problem with condensation dripping off the ducting on to the ceilling. This will continue to happen unless the ducting is insulated.

The firm i used to work had to go and rip down the ceilings in a load of social houses that were less that 2 years old.
Everyone had black ceilings due to unisulated ducting.

Horrible job, i hate ventilation but the company got good money for if.

It is on constant trickle when not on humidistat triggered boost. My guess is someone's put in a long run of flexible ducting and its affecting the extract rate (no way of knowing for certain without ripping down ceilings). At a minimum the overall ducting run must be 7m and could be longer as it's at least that to an outside wall.