Sciencemadness Discussion Board

recharging dehumidifier r410a//r134a//propane

niertap - 5-9-2012 at 19:05

I'm recharging my dehumidifier with refrigerant because it has stopped functioning. I was under the impression that it used r-134a, so i braised on a valve and adapter, and charged it with it. However it appears that it actually is supposed to use r410a...


Currently the cold coils start to get cold enough for the first 2 mins or so, then they warm up to barely cold.


Some Ideas I've come up with are try to add or switch to propane, crimp the long/thin evaporator coil, reduce the pressure( remove some refrigerant), possibly mess with the compressor so it runs to a lower pressure.

It's currently way over charged for 134a, at around 1,000 kPa


some data
---r134a 111,2 tetrafluoro ethane
bp -26.3c vap pressure at 25c 666.1kpa

--propane
bp -42c vap pressure 21.1c 853.16

--r410a 1:1 difluoromethane : pentafluoroethane
bp -48.5c vap pressure 21.1c 1,383kpa


dehumidifier schematic.jpg - 51kB

Rogeryermaw - 5-9-2012 at 23:39

r-410a is not that expensive and can be purchased without certification. protect your equipment and put the proper refrigerant in it. may also want to replace the oil since you have used a different refrigerant.

Praxichys - 23-10-2019 at 05:23

Considering that a refrigerant leak is the cause of the unit's failure, you may be exposing yourself to the risk of a propane explosion if the leak remains after recharging.

Fuel propane is often a mixture of propane and butane and will contain thiols as odorants as well as impurities of nitrogen and CO2. You may not get the performance you expect, and the sulfur compounds might affect the integrity of the oil and pump.

WGTR - 23-10-2019 at 10:07

You've got a problem that needs to be fixed before the unit will work again. These types of systems normally use sealed compressors, and all fittings are brazed/soldered together. There aren't normally any exposed seals or places where the refrigerant can leak from, even over long periods of time.

If there is a leak, it is normally due to damage in the condenser/evaporator, or a worn-out compressor/plugged capillaries, and is probably not worth your time to fix it...unless it is just for fun or for learning. How old is the unit?


Ubya - 23-10-2019 at 10:11

after 7 years he probably threw away his dehumidifier

Praxichys - 23-10-2019 at 11:20

Holy heck, somehow this showed up as a new thread for me... Did it get bumped by (subsequently deleted) spam perhaps? Wow.

Texium - 23-10-2019 at 11:26

Quote: Originally posted by Praxichys  
Holy heck, somehow this showed up as a new thread for me... Did it get bumped by (subsequently deleted) spam perhaps? Wow.
Yep- it got bumped by a sleeper spammer. I deleted the spam account.