Question:
Seven years ago, I bought an air conditioner from Wickes (Model KC-94)
It is the type that is designed to be mounted in a window frame. (Like
what most private houses have in Florida!) For the past four years, I
haven't used it, but this year, needless to say, I neeeded to use it.
It still works fine, but I am pretty sure it is not blowing as cold as
it used to. Do air conditioners such as these need any maintenance,
such as fluid top-up, etc? The label says it uses R22 coolant.
Answer:
If the systems are similar in concept to car air conditioning then I think
your problem may that you haven't run it for four years.
I was once told that the air conditioning needed to be run regularly so that
the lubricants were circulated and these prevented the seals (and even some
of the rubber pipes) leaking.
Small air conditioners for household use do not seem to be designed for long
life. The US average in the south I am told is 4 years. However, as a new
one is around £100, probably it's more costly to repair it than replace it.
R22 is now being phased out, but it's still available in the US. There seem
to be some people offering NU22 as a direct replacement. I'm not sure what
the EU position is.
Car air-conditioning units have generally improved in recent years. They
mostly use FR134a, with revised seals, I believe. FR134a does give problems
with leakage, but not corrosion on correctly designed systems. The refill
life appears to be in the region of 3 years for the systems I have
experienced ( US and Japanese sourced). Both cars with aircon are now 8
years old, neither has needed any attention other than refills. On one, the
manufacturers warranty was for 7 years for major AC component failures. The
US adds a leak sealant to the refrigerant as well as lubrication oil, I
believe that this reduces the leakage rate by say 25%. I haven't seen any
premature failures from this. Compressor life may well be into the 8-12 year
region. Black cabs seem to be having problems with refrigerant hose
breakages in the recent hot weather, probably a batch fault.
