Help sought in stripping an old indoor aircon unit

[Aulus]

Not sure if this fits here but it's like plumbing so I'll give it a go.

I have just visited an offfice, they have an 18 year old Daikin aircon, never been cleaned or AFAIK serviced (still got R22 in it). And it stinks. I had a look inside, the fan assembly is caked with crap & mold, but rest of unit surprisingly clean & dust free.

My question is: does anyone know how I can remove this for cleaning? Or are they better just replacing the whole system?

Model is FT253DA7V1

any help greatly appreciated

 

[dcawkwell]

It should be possible to clean where it is.
There will be filters that can be removed and washed with normal detergent.
You will not be able to remove the unit if it is a split unit as this would
allow the R22 out.
The fan blades should also be accessible and can be sprayed and cleaned.

 

[SimonH2]

I'll second dcawkwell, I used to be (sort of) responsible for the A/C at my last job. Most systems are "sort of" accessible with a bit of thought. With any luck, the filters and intake side of the coil will be at the front and easy to get at. Unfortunately, that's not always the case ...
Be careful cleaning the coil as it's easy to bend the fins (use a brush, and work along the fins, not across them), and it's often easy to cut your hands on the edges.

Check the condensate drain is clear or the pump is working - then you can think about using some water to clean the coil. The drip tray will want cleaning anyway, from the sound of it, it'll be a bit manky too.


If you know what you are doing then it's possible to pump the refrigerant into the outdoor unit - but once you open the pipework you'd then have the problem of how to recommission the system without a vacuum pump to check for leaks and remove the air/moisture that would get in. It's just not worth while.

 

[Aulus]

Indeed, it is a split unit & the the fan cylinder is behind the evaporator, can't see a way to remove it. Seems odd that it would be designed so that you have to degas the system just to remove a dirty fan?!

 

[Boilerman2]

If it is on R22 then it is on "borrowed time" TBH if funds allow, replacement unit would be a good idea as new units use slightly ozone friendlier refrigerants such as R134a or R410

Daikin are very good units

 

[Corgigrouch]

There is always a way to get the fan out without removing the evaporator coil but usually takes a lot of unscrewing of components and finding hidden plastic clips... The black mould that forms on the fan is a pretty disgusting mess.... A sign that they haven't bothered to service the equipment for years. I have seen fans so bad that the blades can no longer pass air through... The fan really needs removing and washing but you can use a cylindrical stiff brush (Such as a flue brush) mounted in a drill on slow speed to brush and run up against the fan... Be prepared black mould will go everywhere so but down a sheet and if the sponge behind the fan is mouldy then it will need cleaning too.... When the staff ask what all the black stuff is, you can truthfully explain that it is decomposing skin.....Then you can offer a price to replace the aircon.. At the age it is it is neither sanitary or efficient.

 

[Aulus]

thanks all. I'll advise a new system.

 

[Aulus]

Update - they had a proper engineer in to have a look. He advises unit can't be cleaned and as it uses R22 it's banned anyway so they must have new units.

So one more (perhaps dumb) question. Is it possible to remove R22 & replace with R410 in such an old unit?

 

[SimonH2]

Update - they had a proper engineer in to have a look. He advises unit can't be cleaned and as it uses R22 it's banned anyway so they must have new units.

Ahh, the British Gas Engineer school of marketing. Much more profit in selling you a new unit (bonus points for false claims about danger or legality to help "scare a granny" as it's known in the plumbing/heating trade) than fixing minor faults in what you've got.

A quick search came up with this thread. Seems that because it's an existing unit, you can carry on using it. The A/C engineer can continue to service it - including topping up the refrigerant with reclaimed gas for several more years. Bear in mind that if it still has enough gas in now, then it's unlikely to need any adding unless something springs a leak or the joints are disturbed (watch out for 'engineered faults')

I can't find it now, but I read an interesting article (PHD Thesis IIRC) a while back from an Australian university. They'd been studying the use of hydrocarbons to replace CFCs, and from memory declared that propane was a good substitute for R12 and a 50/50 mix of propane and butane was a substitute for R22 - and both were chemically compatible with oils and materials using with the CFCs.
Based on that I used to regas my car A/C with propane (blagged an old service hose from a visiting A/C guy at work) - used to cost me pence rather than whatever my local A/C specialists used to charge (close to £100 with VAT IIRC), and seemed to work just fine.
Propane (and other HCs) were common as refrigerants for many years until replaced by CFCs.

 

[Corgigrouch]

Simon, Hydrocarbon refrigerants have their uses, they work very well but your car isn't the right place for them.... A cars airconditioning system hasn't been designed to contain flamable gasses under pressure... Their very design allows them to leak and also places key components where they are prone to be punctured in the even to a minor front end shunt.....You wouldn't use Speedfit for gas or LPG would you?

If you search the net you may also find the Australian professor demonstating how safe Hydrocarbons are in automotive use (I think that he was working for a refrigerant company) He sat in a car, released a can of HC refigerant and then lit a naked flame....

OP alternative non flamable refrigerants are and have been available for the replacement of R22 and work well but only you can decide if the unit is worth saving.... My view is that the unit has done its work and is past its best

 

[SimonH2]

Simon, Hydrocarbon refrigerants have their uses, they work very well but your car isn't the right place for them.... A cars airconditioning system hasn't been designed to contain flamable gasses under pressure... Their very design allows them to leak and also places key components where they are prone to be punctured in the even to a minor front end shunt

Leaks are a minor issue - don't forget that a petrol tank will vent off more flammable vapours every time you take the cap off and fill the tank.

But then consider this.
It's a closed system, designed for the pressure, and apart from damage isn't likely to release the contents. The contents are small - IIRC about 1/2 kg, or was it 1/2 litre. If I'm in an accident, then the propane in the A/C is the least of my worries - it's ignition temp is very high and it will disperse quickly, unlike the brake fluid which is in a flimsy plastic container which will most likely shear off and spray fluid about to ignite on the exhaust manifold.

Apart from a crash, the most likely gas-releasing damage is going to be a puncture in the condenser (eg stone damage). That's going to release it in a controlled manner, and again it will disperse very quickly. Least likely is a sudden and total release into the cabin through a sudden and complete failure of a component.

Oh yes, and I could be carrying up to 100l of liquid propane and another 40l of petrol. But at least they are in steel tanks, unlike most modern cars which have quite flimsy plastic tanks, with clipped together plastic hoses.

.....You wouldn't use Speedfit for gas or LPG would you?

I wouldn't use Speedfit anyway - what's your point ?
A lot of LPG installation do now use plastic pipe.

 

[DeltaT2]

Don't touch it mate, leave well alone. Read this;

http://www.scotsman.com/edinburgh-e...lopments-in-the-legionella-outbreak-1-2339851

 

[SimonH2]

And you should ignore advice from someone who doesn't appear to know the difference between an aircon system and a cooling tower. There is pretty well nil chance of catching legionella from a split system as they just don't present an environment for the bugs to breed.

This is something people round my way do know about - unfortunately.
http://en.wikipedia.org/wiki/2002_Barrow-in-Furness_legionellosis_outbreak
http://www.hse.gov.uk/legionnaires/barrow.htm

You need to differentiate between system types. In these water cooler towers, water is "rained down" through a tower of air which rises by convection - though there are other methods using forced convection etc. While falling through the warm air, water evaporates and the removal of energy (latent heat) causes a reduction in water temperature. Because the water is warm, it presents an environment where the bugs can grow; and because there's the spray, it allows droplets to escape which can carry the bugs into the air where they are breathed in.

In the split systems, the only water involved is what is condensed out of the air - at low temperature. Any droplets that do escape tend to be larger and are unlikely to be breathed in. When not in use, or if the system is also used for heating, the coil will tend to dry out which doesn't leave the bugs anywhere to live.

That's not to say split systems don't need cleaning, but legionella isn't generally considered a problem.

 

[Corgigrouch]

Simon, the old argument about having a tank of petrol on board has been used many times in this type of discussion.... The seals, pipework and tanks used to store fuel on a modern motor vehicle are tested and proven suitable for use with the fuel used, further more the fuel supply to the engine compartment is cut on impact so that the fuel stays in the tank and is not sprayed onto hot exhausts or onto high tension cables... The brake fluid doesn't spray when the reservoir breaks, it drips or slops making ignition much less likely.... Refrigerant escapes uncontrollably once the system is compromised until all of the refrigerant has gone. If the refrigerant used happens to be propane then propane vapour will spray out at pressures of upto nearly 400PSI but more usually 200PSI into an atmosphere where sparks are abundant.

Clearly you have little experience with automotive air conditioning otherwise you would understand that in todays low quality built cars evaporators bursting is reasonably common and over the years I have seen a good dozen evaporator leaks where the refrigerant escaped quickly enough for refrigerant vapour to fill the car quickly.... If it was propane then the consequences could have been quite nasty. Slow leaks are not to be ignored either, if the car was left over night and the cabin slowly filled with propane then a flammable mixture may be waiting for you to unlock the car in the morning and a spark from a relay just adds the ignition to a perfect day

My comment about the Speedfit pipe was to highlight your use of inappropriate materials for the location.... Yes, I'm sure that plastic pipe is used for LPG (I don't have an LPG ticket) but there are locations where plastic for LPG is inappropriate.

Fridges are sealed in the factory and so are manufactured under controlled conditions, R600 is commonly used and is perfectly safe. Your cars air conditioning system is a poor effort of a device badly sealed and made of poor quality components... By "Blowing in" a little propane you have already introduced into your system two of the three elements for a fire. Fuel, air (No mention of you evacuating your system before charging) just add a suitable ignition source...

And you will find that by modifying your car that your insurance is null and void...

 

[SimonH2]

...t in todays low quality built cars ...

Ah well, there's a thing - I don't 'do' modern cars. Pretty well anything I drive is from the days when they were built properly - or at least as properly as British cars ever were

BTW - I've known of plenty of failures of the fuel systems made of parts "tested and proven suitable for use with the fuel used". Just because they are suitable for the fuel used, doesn't make them immune to failure. In one of my own vehicles, the failure was in fact of pipes which turned out not to be all that suitable and a known common fault on that model.

By "Blowing in" a little propane you have already introduced into your system two of the three elements for a fire. Fuel, air (No mention of you evacuating your system before charging) just add a suitable ignition source...

Well the gas/air mix in the system would be far too rich to ignite (propane has a very narrow flammability range) - absolutely zero chance if it igniting internally. And in any case, the system had previously been evacuated and charged (with whatever the substitute de jour for R12 was back then). Had it not been, then I'd have charged it and released the gas (into the air intake, slowly, with engine running (on gas BTW)) to release the air.

And you will find that by modifying your car that your insurance is null and void.

Well it would be if it was a modification. Substituting one refrigerant for another would be difficult to class as such. As you say, R600 is a recognised refrigerant, and R12 was by then already on the "bad stuff" list. But most of all - if it's still in the system after the accident then it's by definition not been a problem; if it's escaped then the evidence has gone.


But all this isn't any help to the OP.