I've been online reading up a bit about air conditioning after seeing a neighbour having it fitted. I notice some installation manuals stress the need for the pipework to be nitrogen purged and pressure tested then a full(ish) vacuum be drawn before introducing the refrigerant. Other sources don't seem to mention this. Is a small proportion of nitrogen in the system a serious defect and what would it's effect be during operation?

On Sat, 30 Jun 2018 15:27:42 -0700, Cynic wrote:

I've been online reading up a bit about air conditioning after seeing a
neighbour having it fitted. I notice some installation manuals stress
the need for the pipework to be nitrogen purged and pressure tested then
a full(ish) vacuum be drawn before introducing the refrigerant. Other
sources don't seem to mention this. Is a small proportion of nitrogen in
the system a serious defect and what would it's effect be during
operation?

I can't see anything too horrible happening. Nitrogen gas is very
unreactive; in fact it's used in place of the noble gas argon in
chemistry experiments where a *relatively* inert atmosphere is required
at minimum cost.



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On 30/06/2018 23:27, Cynic wrote:
I've been online reading up a bit about air conditioning after seeing a neighbour having it fitted. I notice some installation manuals stress the need for the pipework to be nitrogen purged and pressure tested then a full(ish) vacuum be drawn before introducing the refrigerant. Other sources don't seem to mention this. Is a small proportion of nitrogen in the system a serious defect and what would it's effect be during operation?

If you buy one of the pre-charged split units then you can skip all that ;-)


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Not a problem I don't think. How much is a little?
Brian

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"Cynic" wrote in message
...
I've been online reading up a bit about air conditioning after seeing a
neighbour having it fitted. I notice some installation manuals stress the
need for the pipework to be nitrogen purged and pressure tested then a
full(ish) vacuum be drawn before introducing the refrigerant. Other sources
don't seem to mention this. Is a small proportion of nitrogen in the system
a serious defect and what would it's effect be during operation?

Maybe they need to use it in the packaging of crumpets then, instead of
global warming CO2!

Brian

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The Sofa of Brian Gaff...

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Note this Signature is meaningless.!
"Cursitor Doom" wrote in message
news
On Sat, 30 Jun 2018 15:27:42 -0700, Cynic wrote:

I've been online reading up a bit about air conditioning after seeing a
neighbour having it fitted. I notice some installation manuals stress
the need for the pipework to be nitrogen purged and pressure tested then
a full(ish) vacuum be drawn before introducing the refrigerant. Other
sources don't seem to mention this. Is a small proportion of nitrogen in
the system a serious defect and what would it's effect be during
operation?

I can't see anything too horrible happening. Nitrogen gas is very
unreactive; in fact it's used in place of the noble gas argon in
chemistry experiments where a *relatively* inert atmosphere is required
at minimum cost.



--
This message may be freely reproduced without limit or charge only via
the Usenet protocol. Reproduction in whole or part through other
protocols, whether for profit or not, is conditional upon a charge of
GBP10.00 per reproduction. Publication in this manner via non-Usenet
protocols constitutes acceptance of this condition.

Brian Gaff wrote:

Maybe they need to use it in the packaging of crumpets then, instead of
global warming CO2!

If the ammonia plants don't start up again soon, we'll have nitrogenated
Coca-Cola on the shelves!

On 30/06/2018 23:27, Cynic wrote:
I've been online reading up a bit about air conditioning after seeing a neighbour having it fitted. I notice some installation manuals stress the need for the pipework to be nitrogen purged and pressure tested then a full(ish) vacuum be drawn before introducing the refrigerant. Other sources don't seem to mention this. Is a small proportion of nitrogen in the system a serious defect and what would it's effect be during operation?

There are two sorts of system. The small split units (ready filled and
with self-seal connections) suitable for domestic and portacabin type
just need to be connected up. Systems that don't come charged need the
approach that you describe, same as car aircon.

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On Sat, 30 Jun 2018 15:27:42 -0700 (PDT), Cynic
wrote:

I've been online reading up a bit about air conditioning after seeing a neighbour having it fitted. I notice
some installation manuals stress the need for the pipework to be nitrogen purged and pressure tested then
a full(ish) vacuum be drawn before introducing the refrigerant. Other sources don't seem to mention this.
Is a small proportion of nitrogen in the system a serious defect and what would it's effect be during operation?

Professionally installed AirCon usually comes at ambient air pressure
and after installation is nitrogen flushed to remove water vapour and
taken to vacuum. It is then filled with the correct weight of
refrigerant. Doing it thus allows for pipes to be cut to size and
neatly fitted.

Twin units meant for DIY install often come with both indoor and
outdoor units pre-filled with refrigerant and sealed with push fit
fittings. The pipes are positioned, any surplus coiled out of the
way and the push fit joints made. The amount of refrigerant allows
for a small loss when joining the fittings. Shortening the pipes is
not an option.

In article ,
Peter Parry writes:
On Sat, 30 Jun 2018 15:27:42 -0700 (PDT), Cynic
wrote:

I've been online reading up a bit about air conditioning after seeing a neighbour having it fitted. I notice
some installation manuals stress the need for the pipework to be nitrogen purged and pressure tested then
a full(ish) vacuum be drawn before introducing the refrigerant. Other sources don't seem to mention this.
Is a small proportion of nitrogen in the system a serious defect and what would it's effect be during operation?

Professionally installed AirCon usually comes at ambient air pressure
and after installation is nitrogen flushed to remove water vapour and
taken to vacuum. It is then filled with the correct weight of
refrigerant. Doing it thus allows for pipes to be cut to size and
neatly fitted.

Twin units meant for DIY install often come with both indoor and
outdoor units pre-filled with refrigerant and sealed with push fit
fittings. The pipes are positioned, any surplus coiled out of the
way and the push fit joints made. The amount of refrigerant allows
for a small loss when joining the fittings. Shortening the pipes is
not an option.

There are now ones where the pipework and indoor unit are nitrogen
filled to prevent oxygen and moisture getting in during storage, but
you break the seals to fit the pipework, and then purge it by releasing
some of the precharged refrigerant through the pipework after connecting
up, and no vacuuming is required. These do not have self-sealing
connectors and need to be properly plumbed. Note that if you braze
copper refrigerant pipework, if must be nigrogen filled first, because
copper oxide formed inside the pipe at brazing temperatures if there's
any oxygen inside the pipe is a disaster for the system. Traditionally,
aircon was always brazed rather than soldered, but some installers
claim soldering is fine, and that avoids this problem because much less
copper oxide is formed at soldering temperatures, and it doesn't flake
off the inside of the pipe afterwards.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Saturday, 30 June 2018 23:27:45 UTC+1, Cynic wrote:
I've been online reading up a bit about air conditioning after seeing a neighbour having it fitted. I notice some installation manuals stress the need for the pipework to be nitrogen purged and pressure tested then a full(ish) vacuum be drawn before introducing the refrigerant. Other sources don't seem to mention this. Is a small proportion of nitrogen in the system a serious defect and what would it's effect be during operation?

They usually purge it with refrigerant gas.
Frowned on now as it is not supposed to be released to the atmosphere.

On 02/07/2018 06:57, harry wrote:
On Saturday, 30 June 2018 23:27:45 UTC+1, Cynic wrote:
I've been online reading up a bit about air conditioning after seeing a neighbour having it fitted. I notice some installation manuals stress the need for the pipework to be nitrogen purged and pressure tested then a full(ish) vacuum be drawn before introducing the refrigerant. Other sources don't seem to mention this. Is a small proportion of nitrogen in the system a serious defect and what would it's effect be during operation?

They usually purge it with refrigerant gas.
Frowned on now as it is not supposed to be released to the atmosphere.


You might do that, professionals that know what they are doing don't.


Like climate change believers don't install low carbon generation unless
someone is paying them too.