Natural refrigerants - heat-pump friendly?

[Peter_1]

Hi Peter

some limits shown on attached

R's chillerman

Is this something you have to know for the UK the F-gas exams? Do they question you about this? This is something we may not ask for the Belgium F-gs exams but I talk about it in the lessons for max 5 minutes.

[chillerman2006]

Is this something you have to know for the UK the F-gas exams? Do they question you about this? This is something we may not ask for the Belgium F-gs exams but I talk about it in the lessons for max 5 minutes.

No Not F-Gas mate

this was for 'Hydrocarbon handling course'

R's chillerman

[paul_h]

Paul_H, you're of course right but why recover if the unit is already 'empty' and you hardly have time to do such a s..t job like repairing a domestic fridge?

I understand, but the only 'evidence' people who are against HC refrigerants as far as safety reasons, are the stories about how normal safe procedures weren't carried out, and the resulting fire/explosion.
I'm not pro HC by any means, but talking about the flammability, when the job wasn't done the correct way...
OK it was more hazardous and did damage to the fridge with the flame. But none of us like burning HFC refrigerants or oil either.

[chillerman2006]

I understand, but the only 'evidence' people who are against HC refrigerants as far as safety reasons, are the stories about how normal safe procedures weren't carried out, and the resulting fire/explosion.
I'm not pro HC by any means, but talking about the flammability, when the job wasn't done the correct way...
OK it was more hazardous and did damage to the fridge with the flame. But none of us like burning HFC refrigerants or oil either.

Yes I would say so...the video's we watched included systems not fully recovered and leaking tubework ..... they just put a flame to them and all that happened was a torch like flame, similar to a plumbers propane torch, no big bang .... nothing

The time you have a problem is if the exact mixture is present to explode (2-10%) a small leak will disperse easily and are large leak will quickly saturate the air above its explosive mix ... so fairly safe really

there is one big hoax going round where a domestic blew up the kitchen and took the rear wall down .... that was proven by insurance investigators to be a delibrate explosion using the house hold gas appliance .... the refrigerator did not have the charge/mass to cause that damage ... worst way with domestics is if it explodes it will take some of your hair off and you may need clean pants ... well probaly will need the pants !

R's chillerman

[chillerman2006]

Had last a domestic freezer to repair for a friend and he told me that he had a leak around the door heater (discharge pipe around the door) He asked me to bypass the door heater so that I could recharge it with R134a.
Never looked to the nameplate - very stupid of me - and took my brazing torch to solder a schradervalve in the suction port of the hermetic. Process tube came loose from the compressor and you can guess..the R290 (no r134a) was still on it.
We didn't needed to repair it afterwards, it burned as a constant flame of 15 cm to 20 cm high, full power for at least 1 minute. The back of the freezer was complete melted. Lucky, I was in my open shop.
So 150 gr is dangerous, I saw and felt it like and smelled like a roasted chicken.

Hi Peter

A flame and some damage but no explosion

Should help some to realize, be careful but not afraid

R's chillerman

[install monkey]

bp experimentented with hydrocarbons at their services on the m6 at leicester forest. they fitted a coldroom , walk in freezer and aircon was installed, the fridge condensers were foreign and they had to install an extract system for the aircon.dont know how it went after the numpty that installed it crossed his pipework for the condensers so i had to pump down and swap condensers over-it prob got ripped out because on a different site the same guy degassed a 5kw fujitsu with 2kg r22 and charged 350grm on isceon 59, i spent ages pressure testing it to find no leaks!

[al]

Desa

Some others are looking at "miniturising" ammonia compressors:

http://www.ammonia21.com/content/art...ompressors.php

it's funny that NH3 was used in the early days of cooling and i presume a lot of work was done at the time to make domestic versions before the "invented" refrigerants came out, and here we are redoing all this work!!

For me NH3 wins every time, relatively safe, requires a proper training to handle and cheap to buy!

alec

[Magoo]

Thanks al,
A GOOD READ, seems Mycom are onto it with a hermetic scroll for NH3

[MikeHolm]

I could only find the first part of the article and i went to the MYCOM website but there is no mention of anything in the 5-20 kw range except some CO2 machines. Maybe i missed something.

[Bigfreeze]

Theres an Austrian heat pump manufacturer (neura) that uses propane extensively in their range of DX heat pumps up to 30kw. All equipment is outdoors though and the heating water is circulated to the exchanger outside which is its biggest downfall. Achieving COP's of 5+ at the unit, but the losses in having to tranfer the water out of the house is not accounted for in that COP.