Any Fridge / Aircon techies here??

[ptrott]

My wife wants to upgrade to a better egg incubator than the one she made from a foam box a few years ago. It works just fine but it does get through a fair few 25Watt globes, and I guess that at $25 a dozen for the fertile eggs there is a fair chance of them both blowing at night and she loses $60 or more in eggs.

My idea was to get an old bar fridge and revers cycle it so that it heats instead of cools. Just like the Quantum water heaters.
Is there anyone who knows how to do this that could give me directions?
I can silver solder and work with copper tubing.
This may be the very first 'Heat Pump' incubator, another Aussie first????

Thanks in advance.

[Ashore]

Reverse cycle a fridge a bigger job than you may think espically working within the temp range you need
Stay with the 25 watt globes and put a light sensetive diode in there connected to a pizo alarm and a 9volt battery , light fails alarm goes off , a dick smith kit should cost you under $20 or you could rig it up to switch on a second lame as well

[dan76]

check out the thermostats and ceramic bulbs available for reptile heating.
quite simple to hook up

[ptrott]

Thanks for the alternative ideas guys. I still would like to hear from someone in the refrigeration game though.
I remember years ago there were reverse cycle fridges that were called Auto-Defrost.
I would have thought that 38 degrees C would be an easy temp to achieve as it is well within the range of temps that the condenser coils on the back of the fridge attain.
I should also make clear that this reversal will be permanent, so no need to allow for true reverse cycling.
Would not reversing the flow of refrigerant (and the TX valve) to make the coil on the back become the evaporator, do the trick?

[Claw Hama]

One Fridgie, ok X Fridgie, the reverse cycle theing would be a nightmare. And could also be unreliable. Go with the reptile heater as mentioned above or a couple of light bulbs with a thermostat. If one bulb blows and the temperature starts to drop, the thermostat could bring on the next bulb or retile heater. home brew heaters could also do the job, I think some of those may come with their own thermostats too.
Good luck.

[Ashore]

I still would like to hear from someone in the refrigeration game though.

Read the profile
Retired Marine Engineer , still have my fridge ticket , have worked with everything from brine and methane units through to the latest gasses
I was being polite but the bottom line is , you don't have the skills to change a beer fridge and reconfiger the evaporator side to use this to heat the unit you want
Anytime you touch the evap coils with a gas axe you will need to internally acid clean the coils after you are finished to remove all the internal scale produced then fit the proper filters and you will need a fridge licence to remove and re gas the unit etc
BTW auto defrost fridges have a timer , they shut down the compressor and switch on an electric element to remove the ice

[ptrott]

OK OK I'm convinced Don't be offended Ashore, I do believe you.

I had a Fish & Chip shop at one point in my long life. The display fridge evaporator coil went U/S and had to be replaced. The fridgie pumped all the gas into some part of the unit then sealed the pipe, replaced the evap. (s/solder) evacuated the section and released the gas again. From memory it required a small top-up.
There was no acid wash . Sounds like it was a bum job from what you say.

I'll look into the home brew heater. The reptile heaters are a bit big for her little foam incubator.

Thanks gents.

[Uncle Bob]

I use a waterbed heater to germinate seedlings. I brought two of them from our recycling shop shop for $10,they both came with the thermostats too. I reckon these would work you too,

[Gravy258]

try http://www.refrigerationengineer.com. Its the same format as this forum. What you want can be done, but safety first,you have to know what your doing.

regards

gravy

[Timmo]

Fridgey here.

Firstly there is no tx valve in a domestic fridge.

The old cyclic defrost fridges used a hot gas defrost not a reversing valve.

No need to do an acid decontamination because we were purging with nitro weren't we, Ashore?

Its possible to do, personally i wouldnt bother but it's certainly possible.

If I were doing it i'd swap the suction discharge lines on the compressor, put a new drier in, throw in a couple of service ports and go from there. depending on the type of evap coil inside, i'd probably change it to a copper fan coil. The old aluminium plate coils don't like being run at discharge pressure very long.

I'd also be looking at a small fan coil for the outside coil. the passive condensers on new fridges are usually inside the shell so it depends on what sort of fridge you are converting.

Oh, and don't forget to put a reverse acting thermostat on as well.

[ptrott]

Thanks Timmo Gravy & others.

There is a council pick-up coming in a couple of weeks, so I'll be out there looking for an old bar fridge.
Worth a try even if it doesn't work in the end.

Cheers.