350i Heater Fan
Discussion
The most effective mod I've done to mine to increase heater efficiency was to block off the portion of the heater 'box' to the dashboard vents, by fixing an ally plate inside the box.The principal was to keep a more constant section inside the ducting and increase the efficiency, and it works
Matt
Matt
I failed to point out that when i removed the fan i discovered that the multi-plug was wired up wrong. Only the wire to the slowest fan speed was connected. I have swapped the pins around so that i have the two highest speeds connected.
Like you Matt, i noticed that the seal between the face vents and the heater box were crap. I cut some polystyrene insulation and fitted that all around the apertures to seal the box. I also made rubber boots to extend the foot ducts so that it blows directly into the footwell of the car. I haven't driven and tested it yet but i am hoping it will have drastically improved things.
Mick
Like you Matt, i noticed that the seal between the face vents and the heater box were crap. I cut some polystyrene insulation and fitted that all around the apertures to seal the box. I also made rubber boots to extend the foot ducts so that it blows directly into the footwell of the car. I haven't driven and tested it yet but i am hoping it will have drastically improved things.
Mick
extending the footwell vents will definately be better.
During the winter i take the leather trim panels out and that helps a lot.Also i block off the the passenger side (but dont tell her indoors
)
Not sure how blocking off the face vents help though! i thought that was supposed to be fresh air via the vent between the bonnet and windscreen.(which ive already blocked to give recirculating air)
During the winter i take the leather trim panels out and that helps a lot.Also i block off the the passenger side (but dont tell her indoors
) Not sure how blocking off the face vents help though! i thought that was supposed to be fresh air via the vent between the bonnet and windscreen.(which ive already blocked to give recirculating air)
The way the wedge ventilation is plumbed is as follows:
1) Fresh air enters by duct under bonnet fed by scuttle/ base of screen vent, it will cheerfully pick up engine bay fumes also.
2) This duct runs directly to the centrifugal fan intake, the other side of the fan 'barrel' picks up from behind the dash/ recirculates cabin air.
3) The fan outlet then blows into a flat rectangular box, the base of this is where the ducted air (footwell & screen) is taken off and then fed through the heater matrix in a another box. The top of the first rectangular box is where the dash vents are connected.
4) Just inside the entry to the 2nd (heater matrix) box there is a valve / flap which directs the air through the matrix or into the ducted air path.
5)On top of the heater matrix (its mounted flat with air blowing thru top to bottom) is a T-piece duct which has another valve at its intersection to control airflow to screen or thigh.
6) The T- piece then runs up between the two dash vents to the screen manifold and out.
Now my mod blocks off the top portion of the first rectangular box which keeps the duct section a lot more regular and more efficent and restricts the dash vent airflow, allowing the air to go where its needed like for de-misting.
Care is needed not to block off the bottom entry to the heater matrix duct otherwise you'll have nothing at all.
You have to remove the dash entirely and the fan motor then have a feel about and it'll become a lot clearer
Best of luck
Matt
>> Edited by 350matt on Tuesday 25th February 12:29
1) Fresh air enters by duct under bonnet fed by scuttle/ base of screen vent, it will cheerfully pick up engine bay fumes also.
2) This duct runs directly to the centrifugal fan intake, the other side of the fan 'barrel' picks up from behind the dash/ recirculates cabin air.
3) The fan outlet then blows into a flat rectangular box, the base of this is where the ducted air (footwell & screen) is taken off and then fed through the heater matrix in a another box. The top of the first rectangular box is where the dash vents are connected.
4) Just inside the entry to the 2nd (heater matrix) box there is a valve / flap which directs the air through the matrix or into the ducted air path.
5)On top of the heater matrix (its mounted flat with air blowing thru top to bottom) is a T-piece duct which has another valve at its intersection to control airflow to screen or thigh.
6) The T- piece then runs up between the two dash vents to the screen manifold and out.
Now my mod blocks off the top portion of the first rectangular box which keeps the duct section a lot more regular and more efficent and restricts the dash vent airflow, allowing the air to go where its needed like for de-misting.
Care is needed not to block off the bottom entry to the heater matrix duct otherwise you'll have nothing at all.
You have to remove the dash entirely and the fan motor then have a feel about and it'll become a lot clearer
Best of luck
Matt
>> Edited by 350matt on Tuesday 25th February 12:29
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