Hacking the fridge

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ners (relatives). I think they will have a sticker shock; so, give them en ough time to think about it.

pressor to run all the time, icing up the pipe and evaporator coil, raising temperature to over 10 degrees. The cheapest hack is a Raspberry Pi, with temperature probe and solid state relay, without breaking the refrigant se al. Otherwise, $500 just to recharge the refrigant.

ely simple solutions and

h the fridge and if the

the time eating expensive

ermostat/timer that can handle 50A anyway.

damned thing and

er, so

y with. Just

bably did before. There is an older regulator and compressor next to it. We just want to be able to deal with it when that happen again, at least to buy some time waiting for the repair.

be a PITA, if

a couple of wires. Nothing non-standard. If the system is working properl y, the RPi should only monitor it. It needs to pull the plug (via SSR) onl y if it's screwed up like now.

say "NO"

tch a video before working on the system. We want dual compressors and a v acuum pump to empty out either high and low side refrigerant. He should be able to swap out either compressor without pumping out the main system ref rigerant.

system. We just have it there permanently instead of them hooking and unh ooking everytime. If they can't even understand that, they are not qualifi ed to work on it anyway.

he

off (with valves) one or the other. We just want to do it without breaking the pressure lines.

or is either non-functional or disabled. It's been running on low refriger ant 24/7 for some time. I guess it's defrosted by regular power outage. A dding refrigerant without solving the real problem made it worst.

e cover of the pressure switch and measure the OD of that suction line. You do know there are bullet piercing valves that are installed onto pipes tha t do not require brazing or opening up the lines?

It's something like this:

It has flare nut screw on and need to drain the refrigerant to replace it. But even if we replace this, it will likely go bad again, like it did befor e.

Then fix it.

Then replace/fix it.

Then fill it.

That's why HVAC people make good money. They (generally) know what they're doing. Use them.

Then buy the proper hardware and install it. Kludges aren't maintainable.

On Thursday, October 12, 2017 at 6:12:48 PM UTC-4, snipped-for-privacy@gmail.com wro te:

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AM:

owners (relatives). I think they will have a sticker shock; so, give them enough time to think about it.

ompressor to run all the time, icing up the pipe and evaporator coil, raisi ng temperature to over 10 degrees. The cheapest hack is a Raspberry Pi, wi th temperature probe and solid state relay, without breaking the refrigant seal. Otherwise, $500 just to recharge the refrigant.

ively simple solutions and

ith the fridge and if the

l the time eating expensive

thermostat/timer that can handle 50A anyway.

e damned thing and

mmer, so

lay with. Just

robably did before. There is an older regulator and compressor next to it. We just want to be able to deal with it when that happen again, at least to buy some time waiting for the repair.

r be a PITA, if

t a couple of wires. Nothing non-standard. If the system is working prope rly, the RPi should only monitor it. It needs to pull the plug (via SSR) o nly if it's screwed up like now.

t say "NO"

watch a video before working on the system. We want dual compressors and a vacuum pump to empty out either high and low side refrigerant. He should be able to swap out either compressor without pumping out the main system r efrigerant.

he system. We just have it there permanently instead of them hooking and u nhooking everytime. If they can't even understand that, they are not quali fied to work on it anyway.

the

.

h off (with valves) one or the other. We just want to do it without breaki ng the pressure lines.

ator is either non-functional or disabled. It's been running on low refrig erant 24/7 for some time. I guess it's defrosted by regular power outage. Adding refrigerant without solving the real problem made it worst.

ide cover of the pressure switch and measure the OD of that suction line. Y ou do know there are bullet piercing valves that are installed onto pipes t hat do not require brazing or opening up the lines?

cs

. But even if we replace this, it will likely go bad again, like it did bef ore.

No you don't need to replace it. Put one of these on the line

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ote:

om

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ers (relatives). I think they will have a sticker shock; so, give them eno ugh time to think about it.

ressor to run all the time, icing up the pipe and evaporator coil, raising temperature to over 10 degrees. The cheapest hack is a Raspberry Pi, with temperature probe and solid state relay, without breaking the refrigant sea l. Otherwise, $500 just to recharge the refrigant.

ly simple solutions and

the fridge and if the

he time eating expensive

rmostat/timer that can handle 50A anyway.

amned thing and

r, so

with. Just

ably did before. There is an older regulator and compressor next to it. W e just want to be able to deal with it when that happen again, at least to buy some time waiting for the repair.

e a PITA, if

couple of wires. Nothing non-standard. If the system is working properly , the RPi should only monitor it. It needs to pull the plug (via SSR) only if it's screwed up like now.

ay "NO"

ch a video before working on the system. We want dual compressors and a va cuum pump to empty out either high and low side refrigerant. He should be able to swap out either compressor without pumping out the main system refr igerant.

system. We just have it there permanently instead of them hooking and unho oking everytime. If they can't even understand that, they are not qualifie d to work on it anyway.

e

ff (with valves) one or the other. We just want to do it without breaking the pressure lines.

out solving the real problem made it worst.

5A timer ($13, 2 days from Amazon) fixed the range from 2C to 0C. But even 6 cycles of 75%-on, 25%-off has +/2 2C error (4C to 0C). I still think it 's better to have 2 compressors (and coils) alternating.

We are not trying to put kludges in. We are trying to spec out a system th at can maintain stable temperature without switching compressors on/off so frequently. A 500W compressor can run constantly overnight and then switch ing a 1KW compressor during the day.

On Thursday, October 12, 2017 at 9:30:20 PM UTC-4, snipped-for-privacy@gmail.com wro te:

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@gmail.com

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AM:

wners (relatives). I think they will have a sticker shock; so, give them e nough time to think about it.

mpressor to run all the time, icing up the pipe and evaporator coil, raisin g temperature to over 10 degrees. The cheapest hack is a Raspberry Pi, wit h temperature probe and solid state relay, without breaking the refrigant s eal. Otherwise, $500 just to recharge the refrigant.

vely simple solutions and

th the fridge and if the

the time eating expensive

hermostat/timer that can handle 50A anyway.

damned thing and

mer, so

ay with. Just

obably did before. There is an older regulator and compressor next to it. We just want to be able to deal with it when that happen again, at least t o buy some time waiting for the repair.

be a PITA, if

a couple of wires. Nothing non-standard. If the system is working proper ly, the RPi should only monitor it. It needs to pull the plug (via SSR) on ly if it's screwed up like now.

say "NO"

atch a video before working on the system. We want dual compressors and a vacuum pump to empty out either high and low side refrigerant. He should b e able to swap out either compressor without pumping out the main system re frigerant.

e system. We just have it there permanently instead of them hooking and un hooking everytime. If they can't even understand that, they are not qualif ied to work on it anyway.

the

off (with valves) one or the other. We just want to do it without breakin g the pressure lines.

thout solving the real problem made it worst.

25A timer ($13, 2 days from Amazon) fixed the range from 2C to 0C. But ev en 6 cycles of 75%-on, 25%-off has +/2 2C error (4C to 0C). I still think it's better to have 2 compressors (and coils) alternating.

that can maintain stable temperature without switching compressors on/off s o frequently. A 500W compressor can run constantly overnight and then swit ching a 1KW compressor during the day.

Ahh just make the hysteresis a bit bigger? Maybe you want to move the temp sensor further away from the cooling source, that would give a longer time constant.

George H.

But you are.

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owners (relatives). I think they will have a sticker shock; so, give them enough time to think about it.

compressor to run all the time, icing up the pipe and evaporator coil, rais ing temperature to over 10 degrees. The cheapest hack is a Raspberry Pi, w ith temperature probe and solid state relay, without breaking the refrigant seal. Otherwise, $500 just to recharge the refrigant.

tively simple solutions and

.

with the fridge and if the

ll the time eating expensive

thermostat/timer that can handle 50A anyway.

he damned thing and

ammer, so

play with. Just

probably did before. There is an older regulator and compressor next to it . We just want to be able to deal with it when that happen again, at least to buy some time waiting for the repair.

er be a PITA, if

st a couple of wires. Nothing non-standard. If the system is working prop erly, the RPi should only monitor it. It needs to pull the plug (via SSR) only if it's screwed up like now.

st say "NO"

watch a video before working on the system. We want dual compressors and a vacuum pump to empty out either high and low side refrigerant. He should be able to swap out either compressor without pumping out the main system refrigerant.

the system. We just have it there permanently instead of them hooking and unhooking everytime. If they can't even understand that, they are not qual ified to work on it anyway.

r the

r.

ch off (with valves) one or the other. We just want to do it without break ing the pressure lines.

without solving the real problem made it worst.

a 25A timer ($13, 2 days from Amazon) fixed the range from 2C to 0C. But even 6 cycles of 75%-on, 25%-off has +/2 2C error (4C to 0C). I still thin k it's better to have 2 compressors (and coils) alternating.

m that can maintain stable temperature without switching compressors on/off so frequently. A 500W compressor can run constantly overnight and then sw itching a 1KW compressor during the day.

The temperature sensor (already far away from the coil) is not controlling it yet, just logging the data. With a fixed one hour on, half hour off cyc les, temperature still range between 0C and 4C. Ideally, we want 1C to 3C.