R32 -Use of flares on indoor uniits

[Refrigerologist]

We have just attended an R32 training course and posed the question in regard to indoor units and the use of flares inside the room.

In some install manuals the manufacturers ask for the flares to be made outside of the room and in others, from the same manufacturer there is no such stipulation.

We received a reply that there is no special requirement (legislation?) for the location of the flare connections, so the only reason would be for a product requirement.

We will continue to cut the flares off on wall mounted fan coils and then braze, but on other fan coil types that is not so easy, so until we hear different we will use the flares on those with very short stubs outside the units.

Comments?

[Greek_engineer]

I always braze the indoor connections!!

[gozoboy]

That's a question I asked Daikin re VRV indoor units. They said it would invalidate warranty.

[nike123]

And what is the reasoning behind that decision off flare cutting?
Properly made and properly tightened flare joint is as good as welded joint! I have proved that (at least to myself) in my 20 and more years of flaring joints for split air conditioners.

[skilts]

Over the years i have done hundreds of leak & pressure tests, the vast majority of these leaks are on the indoor flare nuts, either the nut has split or not tight enough due to the connection being difficult to make, i would always cut them out.

Skilts

[chilliwilly]

So many different opinions regarding flares, the opinion that is treat as a fact that a flare will eventually leak seems to be applied on a system with a care refrigerant. Manufacturers instructions and guidance seem to conflict with legislation these days.

If a flare is done correctly and not rushed it shouldn't leak. I don't possess the care refrigerant ticket but I do possess the LPG ticket. So correct me if I'm wrong but without looking into the requirements, I would assume if the units charge volume is such that if it leaks into the room or compartment it is installed, it will be below the lower flammability limit. If the lower flammability limit cannot be kept within safe limits resulting from a leak, then lower ventilation should be installed?

I know if you were connecting to units, branching off and joining within a hazardous area, you will only be allowed to to flare. As any hot works would not be permitted without stopping production and applying contingency methods, the risks and associated cost would dictate other methods of cooling or heating.

[frank]

I've seen flares leak and I've seen brazed joints leak......

[chilliwilly]

Indeed, along with thin walled coils and safety devices on receivers. But they are all CE benchmarked, so that must mean it's safe for it to leak! :confused:

[charlie patt]

I still really don't understand why there is any flares on any units we always remove flares where possible I don't really no why new a.c. units don't come with Stubbs on condenser like most fridge condenser when braised you simply don't get as many leaks I realise that very few acs leak on flares but they occasionally do leak braise where you can simple

[PaulZ]

Hi Charlie
I agree that welding the pipe is a better option but I think the reason they have flares is no Hot Work permit is required, installers don't have to have OFN or an Oxy, they only need a flaring tool. I think manufacturers want to make it as simple as possible so non-fridgies can install.
Regards
Paul

[r.bartlett]

Did our first R32 install this week. A Mk II Emura. No different to the r410a and no training needed. In fact I'm not sure there is any training facility over here in Tenerife?. Anyhoo Pipe connections were through the wall

[Makeit go Right]

I think if you are installing R32 systems, it would be better to braze the indoor connections rather than flare them so as to improve the fire-safety risk, even with the blasé {not blaze} play-down by the Daikin trainers. Many engineers braze the inside joints anyway.

BUT, all this fuss over R410a refrigerant is a bit strange. I keep getting panic emails from the big manufacturers/ suppliers telling me time is running by and we have to change to R32 and the world is ending etc, but R410a is not banned, not for a long time yet.

a) R32 is not suitable for the larger systems (too risky) and the VRF/vrv manufacturers are shifting to chilled water equipment to follow the price-conscious consultants/customers. That is how it is.

b) The smaller systems/splits come with a R410a charge that mostly satisfies the install, in which case R410a is not a problem for the installer. After that, how often does one need to replace the gas? Maybe after 5yrs, or longer. And then, customer has to pay for what, 2-3kg of gas? Hardly a bank loan is it?

Seems strange we are being panicked and herded to install R32 systems.

[scoobyru]

To be honest even fgas regs say braze joints where possible if done properly its less likely to leak ever and a much more secure way of connecting . Yes braze joints do leak but to be honst thats due to poor brazing 9/10 times and the procedure itself . This is why these days when ordering expansion valves they will allways give you brazed type first before flared . I've allways been taught to cut flares on wall mount and braze the pipe esp in heat pumps , i have seen the knuckle go on lots of units because of different modes used and the expand and contraction i always thought it was common practise to braze when possible

[Makeit go Right]

Just a bit more on the 'slightly flammable R32' ….. Honeywell has produced a refrigerant that can be used in R410a equipment (instead of R410a). It is still being quality-checked for use in aircon systems, as an acceptable replacement for R410a, but indications are that it will pass through those quality checks over the next few months.

There is vague mention of a minor change to existing (R410a) equipment when changing to this new gas but Honeywell say such costs pale in comparison to changing the existing units/equipment to R32 units.

The new refrigerant is R466A or ‘Solstice-N41’ and offers greater energy efficiency, a GWP of 733 (slightly more than R32’s GWP of 675), but with ZERO FLAMMABILITY.

For customers with existing R410a equipment this is good news. If an existing aircon system breaks down and requires a new charge of refrigerant, then instead of suffering the ruinous cost of the rationed R410a refrigerant or having to replace the equipment with R32 units, it might be preferable to instead refill with this new R466A refrigerant (when it is available).

New systems: If the arrival of R466A could be relied upon – ie a given that it will be on sale next year and that it would meet all its promises about being an inexpensive replacement for R410a refrigerant – then customers could continue to install R410a systems (rather than the slightly flammable R32 systems), knowing that the new R466A will be available by the time that the system might need repairs. Usually, there is (generally speaking) no trouble with an aircon system for at least five years.

[Imp]

But R410a equipment wont be available as all the manufacturers will have moved away from it by then. They dont have the quota under F-Gas phasedown to continue pre-charging with R410a