smoking unit in barber shop

[Pol]

Hi,

We recently encoutered problems with a wall mounted unit in a barber shop. The unit works as it should, but starts `smoking` after about a week`s operation.

We`ve been through the regular stuff, pressures, no leaks, evaporator temp positive, etc, nothing wrong there. The evap is dry is can be, and no condensate is coming out of the drain. It seems to me however that the condensate in some way is blown off the evap, forming the `smoke`. The pulsed air is about 10 degrees, and relative humidity is measured at 100 procent.

After thorough cleaning of the coil, the smoking was gone for about a week, then it came back. We also tried to coat the evap, which lasted for three - four weeks.

Has this got something to do with the products they use in barber shops? anyone familiar with this? I`m looking forward to hear your opinion!

Pol

[lana]

Hi Pol,

By your explanation I understand that "fog" is coming out of the unit.
If this is correct then the cooling process goes beyond the saturation line on the psychrometric chart. This depends on the air dew point and the coil surface temperature.
If you measured the relative humidity around 100% then this reasoning might be true.
I would measure the inlet temperature and relative humidity and the coil surface temperature. Then I would plot the cooling process on the psych chart. Everything will be clear then.

Hope this helps
Cheers

[Andy AC]

Hello Pol.

Had a similar problem on a split installed in a kitchen, it was grease that had settled on the evap coil and when run in cooling produced a white fog/mist, which panicked the staff. A coil flush with frionett and weekly filter cleaning sorted the problem.
As for the stuff they use in barber shops/hair salons - its evil stuff, we installed a daikin 3.5kw inverter in a ladies salon, and it has wrecked the casing. It has mad all the casing go very brittle and has taken the glossiness off the finish, a bit like etched glass. Two of the hinges of the front panel have broken due to the brittleness and the cover now has to be held on with screws. Its only a couple of years old, looks more like 8. It make you wonder whats in that hair spray and stuff and why people put it on their hair.

Andy

[airconadam]

ihave worked in hairdresses and its scary what chemicals they use:eek: they damge almost everythin more than likely is the stuff they use causing the problems good luck

adam

[Pol]

Thx for your replies! Lana, temperatures and relative humidity are all normal; coil surface a bit over 0°C, air in at about 20°C and 40% humidity.

As Andy says, a coil flush with frionett and the fog's gone.... for a couple of days.

[chillin out]

Is it just a cooler? or does the system have a heating mode as well?

It could be that the coil temp is dropping below the limit and it then sends in hot gas to defrost it.

Chillin:) :)

[monkey spanners]

Does the out door unit have a fan speed controler? We worked on one fitted in a kitchen and had to fit a fan speed control to raise the headpressure/dewpoint to stop the unit "raining" on the staff. Didn't get called back so assumed it must have worked.

Jon

[lana]

Hi Pol,

From the replies I reckon that the problem is "the other stuff" not the air cooling problem.
So do what you have to do.
Good Luck
Cheers

[Pol]

I know, this is a tough one. We've been looking at it for quite some time now; we have a general idea what happens, but absolutely no clue how to solve it.

the unit is a Heat pump unit, but only runs in cooling. It's got a three stage fan speed control (stop/low/high). comp is on /off, capillary expansion.

I know it sounds like excess humidity OR low suction causing the unit to freeze OR lack of refrigerant OR an obstruction or something. We've been through all that, had a dozen pretty good refrigeration engineers looking at it (they all started, evidently, checking the above) - to no alas.

IF the problem is to be found in the cooling cycle, how come a frionett coil flush means no more fog for a bit more than a week?

the fog starts 3 - 5 minutes after startup, only to stop 3 - 5 minutes after compressor stop. No water at all in the drain tray (again, if... then why is the drain tray dry?) and you can't find a single drop of water (nor ice) on the coil surface. I really don't get it!

[frank]

Thx for your replies! Lana, temperatures and relative humidity are all normal; coil surface a bit over 0°C, air in at about 20°C and 40% humidity.

As Andy says, a coil flush with frionett and the fog's gone.... for a couple of days.

It may be that the coil is too cold at 0C causing the 40%RH to condensate quickly and be pushed out as small water droplets (fog) in the air stream.

Does it do this on any fan speed setting? Sounds like the air flow is too high (water carryover).

Flushing the coil will temporarily affect the heat transfer capabilities of the coil as you are effectively adding a film to the surface. After a "couple of days" this film will be washed off and then the fogging starts again.

[cool#9]

Hello
Had this problem 2 times in 20 years career ...
1st problem we've lost the customer in 1991 :eek: ( it's one way to resolve the problem but not the best ).

2nd problem i tried frionet 2 by removing heat exchanger and put it in a foaming bath :D then after wash strongly with high pressure water and put it again, no more problem for 1 year ! just enough time to my customer to pay my invoice !!!
Mostly work with daikin's product maybe you'll be interesting of what they tell about...(see item 15.5).
Good luck
cool#9

[sinewave]

Spooky! :p

[Pol]

very interesting reading, Cool#9. And a usefull piece to show the user that he will either have a rather expensive service contract for weekly cleaning :p , or some fog when cooling.

Anyway, he could as well buy other chemicals for ruining his customers' hair!

[Sledge]

I am wondering how the oil/chemical is getting on the coil?
What kind of filter is on these units (never seen a Daikin). Is it one of those metal, washable filters where the media looks like a brillo pad (steel wool). Would this trouble go away with a better quality filter?

Is the unit located near a source of this chemical, perhaps near the wash sink. Would relocating the unit reduce the amount of oil/chemical that would get drawn into the unit.

[Toosh]

Well, looking at this post its the old story which is a familiar tale, the customer wants the cheap job but if everything was taken into consideration the unit supplied would be geared up for the type of intallation such the barber shops chemicals included,its the same as the Itallion restaurant wondering why his coil leaks when he puts his vinegertte dressings in it in the fridge. correct me if I am wrong.

Toosh

[Pol]

The filter 's rather plastic, which I believe to be standard in wall mounted units. I reckon it makes sense, though, we never had the problem with cassettes and ductable units, so as Toosh says, there's a price thingy involved here as well. (I have to add though that both with cassettes and ductable units in barber shops, filters get clogged relatively quick, hence low evap temp, ice or freeze protection, etc..) maybe it would be better to use a ahu with 100% fresh air, but I'm afraid that'll make the price thingy really itchy.

The unit is located behind the counter, sinks etc. on the other side, so we couldn't put the unit any further away.