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tiagomartins007
15-10-2014, 03:03 PM
Hi all!

If I want to change the refrigerant (R404a to R290) of the equipment I need to do some changes like the compressor?

nike123
15-10-2014, 10:53 PM
Yes! Compressor Oil, expansion device etc... Depending on system.

Rob White
16-10-2014, 08:33 AM
.

I'd be more worried about the electrics.

Some R290 systems I've seen use standard R404a compressors
and TEV's but the electrics are different.

Make sure all the electrics are either sealed or up or out of the way of
any possible refrigerant leaks. All fan motors need to be constructed
to a certain standard.

EX rated motors
(see http://www.hse.gov.uk/offshore/infosheets/is3-2010.htm for brief description).

Fortunately most fridge motors are of an EX construction.

Compressor starting and defrost control is the area that needs most attention.
Anywhere on the system where a spark can take place (HP & LP switches) need
to be sealed or removed up and out of the way.

Regards

Rob

.

Rob White
16-10-2014, 08:38 AM
.

In the UK we don't recommend retro fitting an existing fridge to R290.

It can be done but full risk assessments need to be taken beforehand.

Rob

.

tiagomartins007
16-10-2014, 10:16 AM
Thanks guys,

And what you think about performance? It will be better for same custs?

Rob White
16-10-2014, 11:13 AM
Thanks guys,

And what you think about performance? It will be better for same custs?

On paper it should be more efficient.

In real life with all the variations that there are, you might
find it to be no better or no worse.

Rob

.

The MG Pony
16-10-2014, 09:57 PM
I find on real world usages for air conditioning systems it proves to be much better in performance for cooling Vs electrical consumption., keeping in mind these are smaller systems.

tiagomartins007
17-10-2014, 12:12 PM
And what about legislation?

I read this
"IEC 60335-2-24 and IEC 60335-2-89 currently restrict the charge size for commercial refrigerators
and freezers and household refrigerators and freezers to 150 g of flammable refrigerant, respectively.
This charge amount is considered to be safe if the appliance itself is tested for safety. The standard
does not establish safety guidelines for units with a propane charge greater than 150 g"

It meens it cannot be comercialized??

Rob White
17-10-2014, 12:48 PM
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Your location says Braga. Braga in Portugal?
You are European same as me and we use the same legislation.

Depends on what you want it for.

150 g is the limit for mobile and integral systems
1.5 Kg is the limit in public areas (can go upto 5 Kg)
2.5 Kg is the limit in commercial - private areas (can go upto 10 Kg)
10 Kg is the limit for commercial - industrial areas (can go upto 25 Kg)
No limit for a self contained packaged unit in a secure well ventilated area.

This is a European directive so should be the same throughout Europe,
but you will need to do training and research your local rules and regulations.

Rob

.

chilliwilly
25-10-2014, 12:52 PM
From what I remember when doing my first f gas certificate, the 2078, we just covered the storage and transportation of it, 3kg rings a bell when being used/stored in a room of 10 cubic meters. Only once ever come across it once and that was back in the early eighties on an old Carlisle water chiller centralised unit specifically made to run on lpg, that we decommissioned. Infact that was the first time that we ever used a recovery unit, that in turn was built by my boss out of canabalised parts, it took all day to fill 3x 30lb dumpies.

And all the time being supervised by a clark of works that possesed no instruction or method statement, only ever asking us about our method of decommissioning then just simply agreeing with us and giving us permission to go ahead and refrain from smoking and using sources of ignition.

Non of us could understand why this gas was being used, as we only ever come across r12 and r22 back in those days, and once came across a gas that was ether based, and we didn't know it had that inside until venting it. And it was me that found out it was ether as I ended up passing out whilst up the ladder. We just put it down that some boffins must have built it who knew about that kind of thing back then.

I myself don't posses the lpg based licence but do however have the category on my gas safe card to work with it as a fuel. And I should imagine that low level ventilation would be a requirement when being used/stored inside a building? And as other posts state, the controls would have to be either intrinsically safe or class 2 flame proof category as a minimum, or standard controls located within a prescribed zone?

aabbcc
24-03-2015, 10:46 AM
Well ... why not go for the R407A??? instead?
It will be a straight forward change with less hassle ...

Now in case want for research... R290 requires changing the Condenser as well..

For replacing the quantity of refrigerant... A very easy apply is that R290 will be the 1/3 of nominal R404A refrigerant supply. therefore Charge with 1/3 of the nominal capacity as the tech sticker suggest...

Of course you may need to reduce or increase charging by grams...

abp32
30-04-2015, 07:22 PM
having had a lucky escape from a call out i went to were cowboys had filled a r134a system with r290 without telling anyone or even labeling the unit up as a flammable gas i would say stick with r404a as long as possible because when that stuff goes up it really goes up

RANGER1
30-04-2015, 08:46 PM
having had a lucky escape from a call out i went to were cowboys had filled a r134a system with r290 without telling anyone or even labeling the unit up as a flammable gas i would say stick with r404a as long as possible because when that stuff goes up it really goes up

Because of the "Cowboy" problem, we have a procedure & equipment to check systems before working on them, to check refrigerant is not propane etc.
This is used on equipment we have not worked on or have history.
You may only get one chance to check it or get it wrong, before accident happens.