Split Inverter Air Conditioning

[ajstoneservices]

They should have still pulled a vaccum to 1 torr.
If you hear a sound like peas rattling in the pipe work it's because the moisture in the air that wasn't boiled off has turned to ice.
They might have let the refrigerant push the air out though, in which case you won't have any problems but one day they might.

 

[john2k]

They should have still pulled a vaccum to 1 torr.
If you hear a sound like peas rattling in the pipe work it's because the moisture in the air that wasn't boiled off has turned to ice.
They might have let the refrigerant push the air out though, in which case you won't have any problems but one day they might.

At the moment because it is winter I am using it for heating, so in heating mode if there was any moisture in the pipes, will it still turn to ice or will it turn to ice only in cooling mode? The pipe work goes straight out of the wall, so I am assuming I will have to listen to it from outside? Typically how long or how many hours of running before moisture can turn in to ice and be noticeable like peas rattling?

 

[ajstoneservices]

Listen for it outside but let the unit run for 30 minutes or so first. If you don't hear it they have removed the moisture laden air without the use of a vaccum pump

 

[john2k]

Listen for it outside but let the unit run for 30 minutes or so first. If you don't hear it they have removed the moisture laden air without the use of a vaccum pump

In heating or in cooling mode?

When I put it in heating mode at 26 degrees with fan speed set to AUTO, it takes a few minutes to start up. A defrost light turns on and until that light doesnt turn off the heating does start. Also, at 26 degrees in the beginning it doesnt feel like very warm air, but after a while it warms up is this normal?

I notice when starting up the plastic makes creaking sound every so often and then stops once temperature is set, is that because the material is expanding/contracting?

 

[SimonH2]

In heating or in cooling mode?

In heating mode, ice will be a problem in the outdoor unit. In cooling mode, it'll be a problem in the indoor unit. Basically, where the refrigerant is being evaporated from a liquid to a gas and the cold temperatures are found, that's where the ice will form.

When I put it in heating mode at 26 degrees with fan speed set to AUTO, it takes a few minutes to start up. A defrost light turns on and until that light doesnt turn off the heating does start. Also, at 26 degrees in the beginning it doesnt feel like very warm air, but after a while it warms up is this normal?

Yes, that's normal. "Defrost" means it's going through a cycle where it warms the evaporator coil in the outdoor unit to melt any ice on it, then it'll go into cooling mode. It may return to defrost periodically if it detects icing. Depending on conditions, it may also use defrost in cooling mode, but then it's defrosting the indoor unit.
I've seen outdoor units on "not very well designed" systems that have completely disappeared in a block of hoar frost !

It may seem counter-intuitive, but icing is actually a bigger problem with drier air With very wet air, a lot of water will condense and that gives up a lot of latent heat - which keeps the coil temperature up. With drier air, there's less moisture condensing out, so less latent heat given up, so (other factors being equal) the coil will reach a lower temperature. So wet conditions tend to create lots of condensation which runs off the coil, dry air tends to form hoar frost which will eventually block the coil and stop the system working - which is why any well designed system will have a defrost mode (which may be as simple as "stop the compressor, let the coil reach ambient and the ice melt off").

EDIT: Oh yes, a delay on start up is normal. The system has to get to a state where liquid is getting to the cooling end, and the pressures in the system are such that it will evaporate when it hits the valve or capilliary. This can take a while, depending on what state the system was in before it started up, size of the pipework, and a few other factors (commercial systems often have "shut-off" valves to keep the refrigerant as liquid in the condenser when the system is shut down).

I notice when starting up the plastic makes creaking sound every so often and then stops once temperature is set, is that because the material is expanding/contracting?

Yes.

They might have let the refrigerant push the air out though, in which case you won't have any problems but one day they might.

I'd like to know how they managed to avoid the gas mixing with the air, and how they judged just the right amount of gas so that all the air was pushed out without pushing any gas out to atmosphere (which is illegal). So they are either admitting that they left air in, or they are admitting that they broke the law by venting gas

 

[john2k]

In heating mode is it normal for outdoor unit to be discharging water from underneath it? Not the actual drain pipe from the indoor unit but the actual outdoor unit discharging water

 

[stem]

Yes it's normal. When in heating mode, the outdoor unit gets cold and condensation forms on the coils as the air passes over them, thus producing the water. There will be a fair bit too, especially if the air is wet / humid.

In the summer the opposite is true, the indoor coils will be cold and will produce water. Hopefully you won't see any of that though as it will be piped away.

 

[john2k]

I contacted the supplier who is the sole distributer of these units in the UK and asked them. They said: By not using a vacuum pump it is not possible to guarantee all air and moisture has been removed. Purging may work but it's illegal.

You may have no long term problems but there is a small risk of contamination and premature compressor failure.

So contacted the installer again and they have said: Purging a AC system is not illegal if you're purging with clean gasses which we used to push gas through the pipes to clear out anything in the system then caped off pipes before flaring onto unit it's only really required when u have multiple brazes or very long pipe runs

 

[SimonH2]

They are either outright lying, or simply have no clue whatsoever about the law that's been in place for many many years. It's not possible to purge a system like that without releasing some refrigerant gas, and it's illegal to vent the gasses.

Not refrigerant (SF6 is used in electrical switchgear due to it's insulation properties)

An old thread, but shows how long it's been an issue

BTW - the label should say what refrigerant is being used, probably something like "Rnnn" (where nnn is likely to be 2 or 3 digits, possibly followed by a letter) - it makes a slight difference as some are "just bad" while others are "really bad".

Another random link I've managed to find :
https://www.designingbuildings.co.uk/wiki/Refrigerants_in_buildings

 

[ajstoneservices]

I hate these threads because they are used to beat the installer with "well the man on the internet said"

None of us replying to the op know what the installers did or didn't do.

Your installers appear to be saying that they purged the system using ofn(oxygen free nitrogen) we have to use that when brazing and for strength testing. I'm not sure that it should/could be used to drive moisture laden air from the system.

Someone who has f-gas registration should know how to handle refrigerants.