Damp smell from air conditioner when running but not cooling

[stephenM]

Hi all,

I've recently had an MSZ-FH35VE fitted in a fairly small room. It's great - but when I set it to a temperature it can reach easily and close the door, it stops cooling pretty quickly and then blows damp-smelling air around the room, making the atmosphere unpleasant.

Is there a way to make the fan shut down when cooling isn't needed? When it's cooling, the smell is lovely and crisp, but I don't want to freeze myself in order to achieve that!

Thanks

Stephen

[Rob White]

Hi all,

I've recently had an MSZ-FH35VE fitted in a fairly small room. It's great - but when I set it to a temperature it can reach easily and close the door, it stops cooling pretty quickly and then blows damp-smelling air around the room, making the atmosphere unpleasant.

Is there a way to make the fan shut down when cooling isn't needed? When it's cooling, the smell is lovely and crisp, but I don't want to freeze myself in order to achieve that!

Thanks

Stephen

That should not happen.
Was it installed professionally? If so get them back to look at it.

If it is smelling then it could be sucking air from the drain?

It could be a multitude of reasons but it should not happen.

Regards

Rob

.

[stephenM]

Hi Rob,

It was commissioned professionally but I installed the components. I've had it running this evening keeping the temp at 24c, door closed and the atmosphere is bad enough to keep you out of the room. It's a kind of musky smell, not damp exactly but just really unpleasant. Humidity is kept pretty much constant at 60%, which doesn't seem to fit in with how awful the air is. It makes my lungs feel all furry and like I shouldn't be breathing it in.

I installed the condensate drain pipe over quite a long distance - around 7 meters (I want to collect the water in a waterbutt in the back garden). It does drain, but in places the pipe is at quite a shallow angle - I wonder whether that could be causing the condensate tray to not drain fast enough?

[Brian_UK]

Have you fitted a water trap in pipe before it empties into the water butt?

[stephenM]

Hi Brian,


Have you fitted a water trap in pipe before it empties into the water butt?

No - should I have?

[hyperion]

It could potentially be drawing the stale water smell from the water butt back up the drain tube.

[PRESS]

Drains are the usual suspect for foul air in most cases like this. Make sure you have a drain trap on your condensate drain piping as advised above. check if there is no dust of other things on the coils, fan blades and drain tray which may potentially be generating this foul smell.

Regarding the fan and the amount of air blowing you can simply manualy select the air speed from your remote controller. I hope this will help.

[jonjon]

Put a smelly jelly in it

[install monkey]

i had this this week- strangely enough the unit didnt smell, had mould on the louvres
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[Rob White]

i had this this week- strangely enough the unit didnt smell, had mould on the louvres
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I'm not surprised, it looks like it's in a bakery or something similar? :cool:

Bakeries are bad environments for coils.

Regards

Rob

.

[jonjon]

Never knew fascias came in sticky brown

[back2space]

You mention this is a 3.5kw installed in a fairly small room. Seems like the unit is oversized, you also mention that it reaches temperature quickly and then cycles off. Can you advise of room measurements and any other heat loads in the room eg south facing etc.

I've heard of this before... the issue is because the unit starts cooling the coil gets nice and wet absorbing any smells in the room, normally with the system running the coil keeps getting wetter and wetter and any contaminants in the room get flushed through and out the drain but in your case because it isn't running the cooling cycle long enough due to being oversized the compressor cannot respond quick enough to ramp down so it just cycles off. That moisture then evaporates back of the coil and you get a musty smell sometimes almost sweaty smell as its the smells that are left behind.

You need to either call back the installer as its oversized for the room or perhaps you need to run on a low fan speed so that the unit is able to generate enough condensate to rinse the coil through - the outdoor then may be able to ramp down.

A test you could try is set the set point to the lowest setting, then make sure the unit runs for an hour, after this set the set point to a comfortable setting and yes you will get the usual smell of moisture evaporating off the coil but there shouldn't be any bad smells associated with it. Also ensure there is adequate ventilation in the room e.g a window on the catch or internal doors open as these things recirculate any smells in the room be it cooking, breathing & sweating or farting :rolleyes: will be pulled through the a/c and onto the coils.

[monkey spanners]

Try running it in drying mode and see if it is any better, sounds oversized. Did you buy it yourself and then get it installed?

[mikeref]

Oversized kit. Is there carpet? Heavy curtains? Animals in the house? A/C runs a short cycle and keeps humidity too high. Recycled air in these conditions causes bad smells.

Ah... re-read comments and "back2space" on post #12 has already said it better than me:)

[install monkey]

the drain you ran should have a constant fall of 1 cm per mtr, as others have said a u trap will stop smells but if your water butt doesnt stink then the u trap wouldnt be req,
if its a small room,why did they fit a 3.5kw and not a 2.5??
run the unit in heating for a while- does it smell of cat piss?? your coil will need cleaning

have u tried the fan in auto mode- will slow down when at setpoint

[Anz]

Haha I love trying to come up with a better explanation than cat piss to a customer, but that's it cat piss :)

[jonjon]

Haha I love trying to come up with a better explanation than cat piss to a customer, but that's it cat piss :)

"musty smell"

[back2space]

"musty smell"

Sweaty socks or damp towels!

[Anz]

Nah it's definitely cat piss haha

[Anderson245]

Yes that's right a very bad smell comes from air conditioner when the room temperature is equal to the set temperature. We can use the air freshener for this purpose.

[back2space]

It's air fresheners that actually contribute to the bad smell in the first place as they are sucked in and mixed with other odours.

[Anz]

Yeah, u usually find there's sum1 sat under the a/c covering themselves in perfume or tins of lynx at once :)

[install monkey]

usually the female who's past their best- usually in accounts or hr dept!- and theyre trying to describe the smell- they never shout cat piss- i do! haha- mate used grease gobbler on an mitsi evap- melted hole in drip tray! haha

[Anderson245]

Yes that's right a very bad smell comes from air conditioner (http://www.airrescueusa.net/air-conditioning/) when the room temperature is equal to the set temperature. We can use the air freshener for this purpose.

any comment?

[The MG Pony]

ya, fix the problem don't mask it. perfumes and such are an environmental toxin, not a repair.