Garage too hot; Portacool versus mini-split A/C system? - Page 4 - PeachParts Mercedes-Benz Forum

pawoSD · #1 07-19-2018, 12:08 AM

I have a 24k btu split system from Friedrich in my garage. Its also a heat pump so it will crank out serious heat in the winter months too. The other day I worked all afternoon on a car that was hot when it pulled into the garage, in 95 degree weather, and it had it down to 69 and maintained it all afternoon.

I like it cold!

vstech · #2 07-19-2018, 08:24 PM

If anybody wants to install their own minisplit, I can help with knowledge and I could rent tools for the job.
It can be done with basic tools, but having the torque wrenches, allen key and flare tools are best.
Nitrogen, vacuum pump etc...

Not to mention the 5/16 hose adapter...

The key to a long life install is perfect flares properly torqued, and leak free, triple evacuation purged, pulled down to 250microns...

funola · #3 09-21-2019, 11:26 AM

Quote:

Originally Posted by vstech

If anybody wants to install their own minisplit, I can help with knowledge and I could rent tools for the job.
It can be done with basic tools, but having the torque wrenches, allen key and flare tools are best.
Nitrogen, vacuum pump etc...

Not to mention the 5/16 hose adapter...

The key to a long life install is perfect flares properly torqued, and leak free, triple evacuation purged, pulled down to 250microns...

What tools do you have for rent? I am seriously thinking of installing this Fujitsu 33 SEER unit with XLTH myself https://www.fujitsugeneral.com/us/resources/pdf/support/downloads/submittal-sheets/9RLS3Y-RLS3H.pdf because some of the hvac contractors I've met with do not give me a warm fuzzy feeling if they actually do the install with proper equipment or procedures. Some of these contractors sub the jobs out and won't let me speak to their subs to find out what equipment or procedures they use.

Example: one contractor says most of the leaks in their experience through the years of mini split installs is in the evaporator, so they braze the connection at the evaporator instead of using a flare. When asked if they purge the lines with Nitrogen while brazing (to prevent oxidation), their answer was no!

I asked another contractor if they pressure test with Nitrogen and the answer was no! They just do a vacuum, if no leaks, they let the refrigerant out! Not going to name names but this was a Fujitsu Elite contractor.

JHZR2 · #4 09-22-2019, 01:18 PM

Quote:

Originally Posted by funola

Example: one contractor says most of the leaks in their experience through the years of mini split installs is in the evaporator, so they braze the connection at the evaporator instead of using a flare. When asked if they purge the lines with Nitrogen while brazing (to prevent oxidation), their answer was no!

I asked another contractor if they pressure test with Nitrogen and the answer was no! They just do a vacuum, if no leaks, they let the refrigerant out! Not going to name names but this was a Fujitsu Elite contractor.

I can see the logic to brazing, as dependig upon what direction you want the line set I think it may be easier to cut off the connection on the evaporator, have a much shorter lever arm there to stress it, then just pull and secure the line set where it needs to be.

Don’t know enough about precautions on brazing and gas use, but if the systems are line mine, the line set is not lrechsrged, the condenser is. So one could pull hard vacuum on the evaporator afterwards fwiw.

funola · #5 09-22-2019, 02:00 PM

Quote:

Originally Posted by JHZR2

(.................)

Don’t know enough about precautions on brazing and gas use, but if the systems are line mine, the line set is not lrechsrged, the condenser is. So one could pull hard vacuum on the evaporator afterwards fwiw.

Purging with Nitrogen when brazing is to prevent formation of carbon bits inside the copper line that could flake off and clog small passages.

I think most line sets are not pre-charged except MrCool DIY kits that Vstech mentioned earlier.

vstech · #6 07-19-2018, 08:26 PM

Anybody wanting a permitted licensed install in NC or SC I can do that... mechanical and electrical licensed...

vstech · #7 07-19-2018, 08:30 PM

FYI...
the EPA made all refrigerants require EPA certifications this yer...

410a needs EPA certification now too...

pawoSD · #8 07-19-2018, 10:38 PM

There's a lot of split units that come with pre-charged lines and unit, you just put it all together, connect it up and your up and running. Thats how my system works...it has a giant quick connect mechanism on the back to connect the sealed line set. Its 3+ years old and still works great

vwnate1 · #9 07-20-2018, 02:02 AM

Quote:

Originally Posted by pawoSD

There's a lot of split units that come with pre-charged lines and unit, you just put it all together, connect it up and your up and running. Thats how my system works...it has a giant quick connect mechanism on the back to connect the sealed line set. Its 3+ years old and still works great

? What, no links ?! .

vstech · #10 07-22-2018, 11:29 AM

Quote:

Originally Posted by vwnate1

? What, no links ?! .

Pre-Charged Line Sets Are For Real, Right? • MRCOOL

vwnate1 · #11 07-22-2018, 06:33 PM

THANK YOU ! .

ROLLGUY · #12 07-22-2018, 07:21 PM

A couple years ago, I installed a system with six indoor units (one in each side of the "great room", and one in each of the four bedrooms) in my friends house in Mexico. It was made by Fujitsu. The system consisted of the six indoor units, two branch boxes, line sets, and the main unit on the roof. It was actually very easy to do. All the line sets were either 15' or 30' long, so I had to make a coil when needed. It actually worked out pretty nice with three units on each end of the house in the small (only) crawl space. A ducted system would not have worked in this application (flat roof with only a 10' X 15' crawl space on each side of the great room). We did not have pre-charged line sets, so we had a neighbor friend (Wade) come down with us and he did the vac and charge (R410?). Wade was also an MB Diesel guy. He has all the credentials for doing A/C work, as well as the tools to do the job. We have been enjoying the efficiency of this system every time we go down there. It does a great job of cooling down the house quickly, and only in the rooms that will be occupied.

funola · #13 09-21-2019, 11:36 AM

Question for those who diy-ed their mini splits: Did you forego the factory warranty or were you able to find a contractor to vouch for your install and register your unit?

barry12345 · #14 09-22-2019, 01:08 PM

Even many of the hvac guys are taking too many shortcuts. In a way it is cheating the customers. Even when they know better.

JHZR2 · #15 09-22-2019, 01:13 PM

Quote:

Originally Posted by funola

Question for those who diy-ed their mini splits: Did you forego the factory warranty or were you able to find a contractor to vouch for your install and register your unit?

I skipped it.

Years later it still works great knock on wood. But I did buy quality tools and was careful with my work.

If I had to evacuate the system in the future it could be an issue but otherwise hoping for the best. The savings I had for a pretty simple instal would pay for two more new complete units.