I hate sloppy reporting . . .

[Oldgreybeard]

Just remembered that the first fridge I owned was gas powered. Had a small pilot light at the back, at the base of a sort of chimney, and used that to heat ammonia that drove the heat pump. I wonder how a modern take on that system might work? No moving parts, nothing at all to go wrong, in theory it could pretty much work forever. Mine was probably 20 years old when I got it, and the only things showing signs of wear were the door hinges and latch.

[AE-NMidlands]

Just remembered that the first fridge I owned was gas powered. Had a small pilot light at the back, at the base of a sort of chimney, and used that to heat ammonia that drove the heat pump. I wonder how a modern take on that system might work? No moving parts, nothing at all to go wrong, in theory it could pretty much work forever. Mine was probably 20 years old when I got it, and the only things showing signs of wear were the door hinges and latch.

What heat pump? I thought those things had no moving parts and just used the flame (Wikipedia seems to corroborate this.) https://en.wikipedia.org/wiki/Absorption_refrigerator
Technically I suppose any fridge (other than a Peltier device) is a heat pump, but surely nowadays most people wouldn't see the term as applying to a gas fridge?

[Oldgreybeard]

Just remembered that the first fridge I owned was gas powered. Had a small pilot light at the back, at the base of a sort of chimney, and used that to heat ammonia that drove the heat pump. I wonder how a modern take on that system might work? No moving parts, nothing at all to go wrong, in theory it could pretty much work forever. Mine was probably 20 years old when I got it, and the only things showing signs of wear were the door hinges and latch.

What heat pump? I thought those things had no moving parts and just used the flame (Wikipedia seems to corroborate this.) https://en.wikipedia.org/wiki/Absorption_refrigerator
Technically I suppose any fridge (other than a Peltier device) is a heat pump, but surely nowadays most people wouldn't see the term as applying to a gas fridge?

Definitely a heat pump, as it most certainly pumped heat from inside to outside. Definitely had no moving parts, either, just a flame at the back. The thing was about 20 years old when I was given it around 1976, and I had it as my only fridge for around ten years. When I binned it the only thing wrong with it was a broken latch on the door. A colleague at work had it and stripped out the rear plate, that had all the working parts, and turned it into a dehumidifier,, with an electric fan to blow air over the evaporator coil.

[spread-tee]

Just remembered that the first fridge I owned was gas powered. Had a small pilot light at the back, at the base of a sort of chimney, and used that to heat ammonia that drove the heat pump. I wonder how a modern take on that system might work? No moving parts, nothing at all to go wrong, in theory it could pretty much work forever. Mine was probably 20 years old when I got it, and the only things showing signs of wear were the door hinges and latch.

What heat pump? I thought those things had no moving parts and just used the flame (Wikipedia seems to corroborate this.) https://en.wikipedia.org/wiki/Absorption_refrigerator
Technically I suppose any fridge (other than a Peltier device) is a heat pump, but surely nowadays most people wouldn't see the term as applying to a gas fridge?

We still use one of those fridges in our Caravan, it does use a good splash of Propane to keep it running though. For some reason it did go wrong once, just stopped working just after filling it up with a load of shopping. We called a caravan mechanic who asked me to identify which bits were hot and which were cold, then told me to take the fridge out of its housing and turn it upside down for no more than ten seconds. I genuinely thought I was being pranked, but desperate to save all our fresh shopping did so, and it has worked flawlessly ever since!!

Isn't the definition of a heat pump a device that takes heat from a cooler area and dissipates it into a warmer area? irrespective of how it is powered.

Desp

[Oldgreybeard]

We still use one of those fridges in our Caravan, it does use a good splash of Propane to keep it running though. For some reason it did go wrong once, just stopped working just after filling it up with a load of shopping. We called a caravan mechanic who asked me to identify which bits were hot and which were cold, then told me to take the fridge out of its housing and turn it upside down for no more than ten seconds. I genuinely thought I was being pranked, but desperate to save all our fresh shopping did so, and it has worked flawlessly ever since!!

Isn't the definition of a heat pump a device that takes heat from a cooler area and dissipates it into a warmer area? irrespective of how it is powered.

Desp

That rings a bell, I thingkI had to do something similar with mine, when it stopped working after I'd let the gas bottle run out (I ran it on calor gas). As you rightly say, it was definitely a heat pump, as it pumped heat from inside to outside. Probably not very efficient, but I was given it for free at a time when there was no way I had enough money to buy a fridge. The cooker I had at the time (also donated) ran on calor gas, so it made sense to have one bottle run both.

[AE-NMidlands]

I did say "technically I suppose any fridge (other than a Peltier device) is a heat pump, but surely nowadays most people wouldn't see the term as applying to a gas fridge? "

Nowadays, with the amount of work we are expecting them to do, is anyone suggesting we could get the required output from anything other than the A2A or ground- or water-source things that people have been describing and praising recently?
A

[Oldgreybeard]

I did say "technically I suppose any fridge (other than a Peltier device) is a heat pump, but surely nowadays most people wouldn't see the term as applying to a gas fridge? "

Nowadays, with the amount of work we are expecting them to do, is anyone suggesting we could get the required output from anything other than the A2A or ground- or water-source things that people have been describing and praising recently?
A

Even Peltier devices are heat pumps though, as they pump heat from the cold side to the hot side. Pumps don't need moving parts, our body is full of little pumps without bits that move, doing things like pumping molecules from one side of a membrane to another. We even have drugs to regulate some of these pumps. Anyone that's had a stomach ulcer will probably be familiar with proton pump inhibitors. Drugs that inhibit the hydrogen potassium ATpase proton pumps across the membrane to the stomach, so reducing acid production.

I agree that, in the sense of heating and cooling devices for homes we are more familiar with mechanical fluid/gas compression - expansion heat pumps, but there are ways of driving even a compression - expansion fluid/gas heat pump without needing mechanical moving parts. At the moment, it's partly the properties of the working fluid and the available compressor technology that restricts the working temperature range of the heat pumps we have, so it is possible that we may go back to heat pumps with no moving parts in future.

As an aside, one of the most impressive heat pump installations I've heard of was powered by town gas. It heated and cooled the Royal Festival Hall, drawing water from the Thames as a heat source. The thing was a conventional (reversible) compression - expansion heat pump, but the compressor was driven by two Rolls Royce Merlin engines (as powered the Spitfire and Hurricane), converted to run on town gas. That has to be one of the most impressive heat pumps I've ever heard of.

[Moxi]

I saw two shocking fails by the "tell a giraffe" and the "daily fail" this morning,
the first was an article about 7 drug positives at sellafield with a photo of Hinckley B power station ? plus thats seven positives in a whole year for a site with 10,000 plus workers - not really news or surprising.

The second was even better showing snow falling this morning in Cumbria with a series of photos in clear daylight all captioned "snow falling today in Cumbria" when I was reading the article at 7am in the dark ! All I can think is that Cumbria is 3 hours ahead of the rest of the UK

I mean the papers wouldnt put any old photo up and tell fibs would they ?

Moxi

[Oldgreybeard]

The drugs testing thing is interesting, as my experience (and that of my former colleagues) shows that mass testing is far from being reliable. For years we had mass urine testing at work, and it would always, without fail, give a high number of false positives. It got so that no one was even slightly worried if they got a positive, as they knew full well that the second test would most probably be negative.

[AE-NMidlands]

The drugs testing thing is interesting, as my experience (and that of my former colleagues) shows that mass testing is far from being reliable. For years we had mass urine testing at work, and it would always, without fail, give a high number of false positives. It got so that no one was even slightly worried if they got a positive, as they knew full well that the second test would most probably be negative.

I was in a safety-critical job (and the new owner wanted to get rid of me, can't imagine why) so I was called for a "random" drugs test one day when I was in the office. It came up positive and my immediate boss - who also hated the new owner (said openly that "He was not fit to run a whelk-stall") called me in and asked if there was any way opiates could be in my system...
we had had eaten part-baked rolls, which included some covered with loads of poppy seeds...
"OK, no problem!"

A