Fixing a DeLonghi PAC L90 Portable AC - Possible?

[Prius_Cub]

Hi everyone, I just picked up a free DeLonghi PAC L90 portable air conditioner off Craigslist today. It was described as non-working, so I assumed that either it was a matter of condenser/evaporator coils caked in dust or perhaps a faulty thermostat. Got it home, cleaned out the condenser coils which were caked with dust (still a bit of work left on them). Plugged it in to test it out and the fan ran fine, then after 2-3 minutes the compressor kicked in. No cold air but the compressor isn't cycling on and off like I would assume a low charge of R-22 would cause.

The first few inches of the high side line exiting the compressor get hot but I feel no warmth at the condenser coils. Any ideas or is it probably just low on refrigerant? I would like to make this work since it supports the dual hose setup for exhaust and cooling intake for the condenser and replace my window unit with it, but I'm not handy with refrigerant or soldering copper or anything like that, nor do I have the tools to vacuum the lines out. But would it be possible to put in a low-side tap of some sort and charge with a compatible refrigerant?

Forgive me if I'm ignorant on the subject but if I can get a yes or no on this and if it's something I could do easily, can someone point me to a thread or how to for this? If not, I'll give up on the folly of the idea and just salvage any good electronics for other projects and recycle the rest.

I've included photos of the unit with the casing off.

[jeff5may]

What you are looking for is a piercing access valve. There are two types: solder and bolt-on. Solder types are cheaper and more reliable. The bolt-on type is easy to install, but just don't touch it much or it will leak (kind of like flare fittings). Supco makes the Bullet piercing valves, which you want to install on the low pressure side of the refrigerant loop. With this unit, you want to put it on the insulated line shown in pic #2 somewhere behind the blue sticker.

Before you open up the refrigerant loop, there are some checks you can do. Since the unit tries to run, you can listen to the metering device. Fire the unit up, let the compressor run for a minute or so, then unplug the unit and quickly listen to the metering device. For a short time after the compressor stops, it should make a gurgling or whooshing noise as the pressure equalizes. If the charge is low, it will make a faint hissing noise for much less time.

There is another check you can do to check for leaks. Fire up as before, unplug, then quickly douse the condensor (bottom coil) with soapy water. I suggest a bug sprayer or a bucket. If no bubbles appear, do the same thing with all the copper plumbing. It may take some time to check all the plumbing, but you most likely will have to do this even if you open the refrigerant circuit. If you have any leaks, they will show up.

There are lots of threads in the geothermal/heat pump forum where members have revived, repaired, or troubleshot their units. If you decide to try to plug leaks, recharge, or otherwise repair the refrigerant loop in this unit, expect to spend at least $30-75 if you can borrow tools. If not, and you must purchase tools, expect to spend $100 at least. There are ways to rig up and repurpose equipment to trade money for skill and time, but if you aren't resourceful, just beg, buy, or borrow the right tolls for the job.

By the way, these units rock as far as efficiency and utility!\

Good luck,

Jeff

[AC_Hacker]

Originally Posted by Prius_Cub

Hi everyone, I just picked up a free DeLonghi PAC L90 portable air conditioner off Craigslist today...

If I were you, I would consider this to be a donor unit. I wouldn't even try to fix it, as so many compromises have been made in the design to achieve portability, that efficiency suffers. There are many of these units (made by various manufacturers) flooding into thrift stores, Craigs List, etc. I got one for free... the woman who had it said she would give it to me for 'nothing', but implied that sexual favors were part of the bargain. Long story short, I was able to preserve my purity and she gave it to me anyhow.

The unit probably had a slow refrigerant leak... it could be anywhere. The 'coils' (AKA: heat exchangers) are probably undersized.

jeff5may is pretty right on the tool costs, etc. His advice is all good. However, I would advise you to learn how to do some radical modifications on this unit... it is really a lot of fun.

You have arrived at the best place on the Internet to find out what extraordinary things can be done with this equipment, and how to do it.

Read around on various threads here. Learn to use the web site's search engine, sometimes, but not always, Google can be more helpful. Learn, learn, learn!!

Far as I'm concerned, you have reached the the door to insanity... and we are here to help pull you through.

Best,

-AC_Hacker

[Prius_Cub]

Thanks jeff5may I thought it would be great to use in a future project (when I do get my hands dirtier) so I snapped it up.

I checked the metering device as you suggested but I hear no hissing after cutting power to the unit. Guess I've got a leak or leaks to find...

My brother works for a heating and cooling company so I'll ask him if they do this type of repair work on the side or if he might have the tools to borrow.

[Prius_Cub]

AC_Hacker, thanks for the suggestion, this would be great to "practice" on and get familiar with modifying this type of equipment and learning the basics of refrigeration and cooling.

[Prius_Cub]

Alright, brother said he can't do it without port, so I'm just waiting on a supco bullet valve, so he can charge it and I can look for leaks again. I couldn't find any It must have all leaked out during usage/storage by the previous owner. Oh well, looking forward to find out if it can be fixed cheaply.

[Prius_Cub]

Got two Supco bullet piercing valves today, attached them and had my brother vacuum it down and I filled it with a cheap can of R134a, not enough to get to the pressure it needs but enough to check for leaks so I can seal them. Then to fill it up. This unit is destined for charity first for a friend whose central air is out and they won't be able to fix it for a while, and perhaps may have a future life as an air source water heater. Overall very pleased with my progress so far!

[jeff5may]

Dare I say it? I do. You could use propane.

[Prius_Cub]

Hmm...I don't think I'm that adventurous yet, lol. But we'll see what the future holds

[torycooper]

It's very hard to say without seeing it. But, you can hire some technician from air conditioning repair palm beach gardens, who can help you at an affordable rate.