I am looking at a bathroom extractor from a block of flats (30 years old).
It's an Aidelle Loovent twin fan model (feeding into a negative pressure
building-wide extract duct system).

I'd had a quick look at their products and found a wide range of fans
with dual speed for things like continous running and boost with
occupancy or humidity, so I had assumed one fan was going to be the
continuous running and the other for boost, although their current
products look to be just one fan with dual speed working.

The thing was only working intermittently, and noisy. On taking the
vent off the front, it was solidly packed with 30 years of dust, and
difficult to see anything. I could feel one fan ws jammed, and the
other one was stiff. I couldn't find the mounting screws or where
the cable came in due to the dust, so had to schedule a second visit
with a compressed air can.

Having got the thing down, and opened it, and got a buckload of dust
out (which strongly resembled soot), I worked out its design. This
model has only a single feed and runs continuously. The circuit board
has tracks for a run-on timer, but no components are fitted except the
mains fuse, which bizzarly covers only one of the two fans, the one
that is jammed. Fuse is not blown but winding is open-circuit, so
that one's had it. The other fan works, just. I disassemble and clean
and re-oil the sleeve bearings, reassemble and spin up. Strangely, one
fan is using 29W, but the whole unit claims to be 30W. I then try to
work out the switching of the fans. The dead one has an air-flow switch
which cuts in the working one when the flow is low.

So it looks like this unit is designed to run with just a single fan
at once. When the primary dies (no air flow), it then switches over
to the secondary fan. After 30 years, the second fan is on it's last
legs. Interesting that they have designed an extractor fan which is
intended to have the life of two motors consecutively, and not something
I've seen before in an extractor fan. I suspect it was a high priced
option, which fits with what I'm finding with other original fit items
in the flat.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Sat, 6 Jul 2013 23:48:34 +0000 (UTC),
(Andrew Gabriel) wrote:

I am looking at a bathroom extractor from a block of flats (30 years old).
It's an Aidelle Loovent twin fan model (feeding into a negative pressure
building-wide extract duct system).

I'd had a quick look at their products and found a wide range of fans
with dual speed for things like continous running and boost with
occupancy or humidity, so I had assumed one fan was going to be the
continuous running and the other for boost, although their current
products look to be just one fan with dual speed working.

The thing was only working intermittently, and noisy. On taking the
vent off the front, it was solidly packed with 30 years of dust, and
difficult to see anything. I could feel one fan ws jammed, and the
other one was stiff. I couldn't find the mounting screws or where
the cable came in due to the dust, so had to schedule a second visit
with a compressed air can.

Having got the thing down, and opened it, and got a buckload of dust
out (which strongly resembled soot), I worked out its design. This
model has only a single feed and runs continuously. The circuit board
has tracks for a run-on timer, but no components are fitted except the
mains fuse, which bizzarly covers only one of the two fans, the one
that is jammed. Fuse is not blown but winding is open-circuit, so
that one's had it. The other fan works, just. I disassemble and clean
and re-oil the sleeve bearings, reassemble and spin up. Strangely, one
fan is using 29W, but the whole unit claims to be 30W. I then try to
work out the switching of the fans. The dead one has an air-flow switch
which cuts in the working one when the flow is low.

So it looks like this unit is designed to run with just a single fan
at once. When the primary dies (no air flow), it then switches over
to the secondary fan. After 30 years, the second fan is on it's last
legs. Interesting that they have designed an extractor fan which is
intended to have the life of two motors consecutively, and not something
I've seen before in an extractor fan. I suspect it was a high priced
option, which fits with what I'm finding with other original fit items
in the flat.

A RAID fan. Better than built-in obsolescence.



--
Graham.

%Profound_observation%

Also I have seen a lot of fans that went open circuit and the only issue was
that the winding was terminated by some form of rivet or similar and this
got corroded and wnt open circuit.
Howeve as has been said, the age would suggest its had its best days by
now!
Brian

--
From the Sofa of Brian Gaff Reply address is active
"Graham." wrote in message
...
On Sat, 6 Jul 2013 23:48:34 +0000 (UTC),
(Andrew Gabriel) wrote:

I am looking at a bathroom extractor from a block of flats (30 years old).
It's an Aidelle Loovent twin fan model (feeding into a negative pressure
building-wide extract duct system).

I'd had a quick look at their products and found a wide range of fans
with dual speed for things like continous running and boost with
occupancy or humidity, so I had assumed one fan was going to be the
continuous running and the other for boost, although their current
products look to be just one fan with dual speed working.

The thing was only working intermittently, and noisy. On taking the
vent off the front, it was solidly packed with 30 years of dust, and
difficult to see anything. I could feel one fan ws jammed, and the
other one was stiff. I couldn't find the mounting screws or where
the cable came in due to the dust, so had to schedule a second visit
with a compressed air can.

Having got the thing down, and opened it, and got a buckload of dust
out (which strongly resembled soot), I worked out its design. This
model has only a single feed and runs continuously. The circuit board
has tracks for a run-on timer, but no components are fitted except the
mains fuse, which bizzarly covers only one of the two fans, the one
that is jammed. Fuse is not blown but winding is open-circuit, so
that one's had it. The other fan works, just. I disassemble and clean
and re-oil the sleeve bearings, reassemble and spin up. Strangely, one
fan is using 29W, but the whole unit claims to be 30W. I then try to
work out the switching of the fans. The dead one has an air-flow switch
which cuts in the working one when the flow is low.

So it looks like this unit is designed to run with just a single fan
at once. When the primary dies (no air flow), it then switches over
to the secondary fan. After 30 years, the second fan is on it's last
legs. Interesting that they have designed an extractor fan which is
intended to have the life of two motors consecutively, and not something
I've seen before in an extractor fan. I suspect it was a high priced
option, which fits with what I'm finding with other original fit items
in the flat.

A RAID fan. Better than built-in obsolescence.



--
Graham.

%Profound_observation%

In article , Andrew Gabriel
writes

So it looks like this unit is designed to run with just a single fan
at once. When the primary dies (no air flow), it then switches over
to the secondary fan. After 30 years, the second fan is on it's last
legs. Interesting that they have designed an extractor fan which is
intended to have the life of two motors consecutively, and not something
I've seen before in an extractor fan. I suspect it was a high priced
option, which fits with what I'm finding with other original fit items
in the flat.

Yep, dual redundant fans used to be a building regs requirement where
there was no natural ventilation.
--
fred
it's a ba-na-na . . . .