ffutures: (Mad scientist)
ffutures ([personal profile] ffutures) wrote2006-08-22 09:29 am

Stupid fridge question

Wearing my mad scientist hat again...

Just had the fridge-freezer delivered and they told me it has to sit for three hours before plugging in "because they don't use CFCs any more."

I knew that CFCs were banned, but I hadn't thought about what replaced them and why it would need so much longer to stand. I know that early fridges used ammonia, have they gone back to using that or is it something else?

Update Got home - fridge appears to be pretty cold, ditto freezer, so presumably working OK. I'll bung some frozen food in a little later, once I've checked the temperature. Now where did I put the freezer thermometer.

later Minus 18 - should be OK.
ext_15169: Self-portrait (The Shadow Knows)

[identity profile] speakr2customrs.livejournal.com 2006-08-22 08:42 am (UTC)(link)
A quick look at Wikipedia http://en.wikipedia.org/wiki/Refrigerator told me:

"Modern refrigerators usually use a refrigerant called HFC-134a (1,2,2,2-tetrafluoroethane) instead of freon, which has no ozone layer depleting properties."

[identity profile] ffutures.livejournal.com 2006-08-22 08:50 am (UTC)(link)
Thanks - don't know why I didn't think of that.
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[identity profile] akicif.livejournal.com 2006-08-22 09:14 am (UTC)(link)
if I remember right, the working fluid in a refrigerator needs to be in a certain zone on its phase diagram so it can easily be kicked backwards and forward across the line between liquid and vapour, and this zone changes with chemical composition with HFCs being not as good as CFCs. You also want the liquid to be in the right part of the pumping system before you switch it on.

I'm guessing that when in transit the fluid gets shaken up and you end up with vapour locks, or condensed liquid where it shouldn't be?

[identity profile] gonzo21.livejournal.com 2006-08-22 09:36 am (UTC)(link)
This is what I was told, a fridge in transit might be knocked around too much, or carried upside down by the delivery guys, or something, so you have to let them sit to avoid vapour locks or somesuch.

Apparently you should be very very careful when moving a fridge yourself too. And again, avoid rocking it too much, and let it sit for a while before switching it back on.
ext_58972: Mad! (Default)

[identity profile] autopope.livejournal.com 2006-08-22 09:57 am (UTC)(link)
Same goes for air conditioning units and similar (as I discovered, when buying a portable one for the recent heat wave -- and couldn't use it for 24 hours after I got it home, during which time the weather broke).

[identity profile] gonzo21.livejournal.com 2006-08-22 10:00 am (UTC)(link)
Ouch, tough luck. Just goes to show that the weather gods do indeed have a sense of humour though.

I can't remember where I read this, but apparently you can make a makeshift air conditioner by nearly filling a 2 litre coke bottle with water, freezing it (carefully taking care that it doesn't split in your freezer), then setting it in a bowl in front of a fan. And it will produce a marked cooling effect.

I haven't tested it myself, but it sounds an intriguing idea.

[identity profile] daveon.livejournal.com 2006-08-22 10:01 am (UTC)(link)
It's nothing to do with the CFCs, its been a problem for Freezers pretty much forever. The issue is more to do with how the collant settles in the compressor. You need to make sure that the compressor is full of collant and there are no airbubble or other gaps before turning it on otherwise you could dramatically reduce the efficiency of your freezer and the life time of your freezer.

[identity profile] adrian-middle.livejournal.com 2006-08-22 11:16 am (UTC)(link)
HFCs have their own problems, because they may not effect the ozone layer but their impact on the troposphere is still an issue. When they break down HFCs contribute to acid rain.

Some fridges uses Hydrochlorofluorocarbons (HCFCs), which are not banned. They do, however, have a lesser effect on both the ozone layer *and* the troposphere. So thats depleted ozone *and* acid rain.

There is something new being promoted by Greenpeace called "Greenfreeze". This uses pentane insulation and isobutane (all hydro and no chloro or flouro).

[identity profile] w00hoo.livejournal.com 2006-08-22 11:22 am (UTC)(link)
One of the CSI (IIRC Miami) episodes had a similar thing which I think they referred to as 'swamp air conditioning' or some such. Basically a big chunk of ice and an electric fan. Spoiler I guess ()

[identity profile] vicarage.livejournal.com 2006-08-22 11:26 am (UTC)(link)
Swamp coolers are evaporative coolers that blow air past damp pads. They work well in the dry air of the West, but would be useless in Florida.
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[identity profile] uninvitedcat.livejournal.com 2006-08-22 11:27 am (UTC)(link)
Despite having worked in the technical department of one of the big white goods manufacturers, all I can remember about coolants is that they switched from a poisonous one (invisible and odourless) to an explosive one. Or possibly the other way round...

[identity profile] ffutures.livejournal.com 2006-08-22 11:42 am (UTC)(link)
Thanks everyone - fortunately I took the guy seriously and gave it the full three hours, so hopefully it's OK. Seemed to be working properly before I left for work anyway, though it's early to tell. I'll see when I get home.