Who makes best heat pumps (HVAC)

[kenmac]

When Installing, if they aren't replacing the line set. You want to make sure you get all the contaminants out of your old line set. Flush the lines,and pull vacuum down to at least 400 microns.
If you are using new line set, purge with nitrogen and pull vacuum to 400 microns measured with a micron gauge

 

[daugen]

so pulling vacuum down that far simply must take more time and shortcutting the process possibly leaves unwanted junk in the lines.
Another cleanliness is next to godliness situation I assume.
This all speaks to installation quality of course

 

[mmancuso13]

The deeper the vacuum the more moisture is removed from the system (removed by flashing to gas and being sucked out by the AC pump). Typically 500 microns is where I like to be. Assumed also is that a new filter dryer will be installed on the system every time a full evacuated and recharge is required.

 

[kenmac]

so pulling vacuum down that far simply must take more time and shortcutting the process possibly leaves unwanted junk in the lines.
Another cleanliness is next to godliness situation I assume.
This all speaks to installation quality of course

moisture is the killer. It doesn't mix well and will cause acids to form in the system. It does take time to do the job correctly.

Most people can't afford to pay someone to install a system the correctly the first time, but they always can afford to pay someone else to return and do the job right the second time around

 

[CADplans]

moisture is the killer. It doesn't mix well and will cause acids to form in the system. It does take time to do the job correctly.

I had to go digging for a conversion calculator,, and I found it.

We used to remove moisture from aircraft instruments,, so the "gauge" would not fog during a dive.

At 500 microns, the moisture would not come out of the gauge.
Even 36 hours at that level of vacuum, the gauge test would fail.
The test was to heat the gauge to 120 degrees F,, then hold an ice cube to the glass face for 30 seconds,
No moisture was allowed to appear inside the glass.

The gauges had to be run through the 500 micron chamber a half dozen times, at 36 hours each run.

I had purchased a vacuum furnace for the company, and we were heat treating and brazing in it.
I was told about the problem with the instruments, I told them I wanted to try running a gauge in the furnace.

This furnace developed a vacuum of 0.000005 Torr
That ends up being 0.005 microns vacuum, rather than 500 microns.

Needless to say, none of the gauges that went through the furnace EVER had a moisture problem,,

An HVAC installer can not get that level of vacuum,, EVER,,,
(the pump I used weighed more than the van the HVAC guy drives )

so, instead of removing the moisture, they install a "dryer" that the refrigerant flows through.

I have read online that some systems do not have dryers,, that would be a MAJOR problem.
If and when I get a new heat pump, I will insist on an extra dryer being added to the system.

Here is a dryer question response that I found elsewhere:

I'll put it to you this way

I have been installing and repairing air conditioning systems for 34 years now

And from Day 1 We did things this way. Pops taught me

Properly sized liquid line filter drier installed before the evaporator

Proper vacuum

Some typeof Time delay for short cycle protection

With fingers left over I can count the number of warranty compressors I've replaced

Some may say it is a waste of money

I liken it to cheap insurance

Most manufacturers now factory install them in the condenser

and this;

About the same as my thoughts for oil filters on cars.

So, if you think of the dryer as a filter, anytime the system is opened, the dryer should be changed.
Even if the system is new, and only run a dozen hours,, if it was open, it needs a new dryer.

 

[daugen]

so this is for the same reason large commercial air compressors have air driers?

too bad they haven't come up with a water compatible refrigerant that might absorb the issue

My Trane heat pump blew its large capacitor requiring a service call, quick fix, they carry them on the truck. Was told it was a common problem.
Would that normally indicate I don't have the right slow start circuit? Do Trane's blow more start up capacitors than other brands? (I'm sure the adhesive on their
brand label must draw more juice...)

 

[LD1]

too bad they haven't come up with a water compatible refrigerant that might absorb the issue

Good thing they haven't, probably work out about as well as Ethanol in our fuel

 

[Tractor Seabee]

In the old days we evacuated every system overnight. We had portable 2 stage pumps that in the 60s cost $1K. A good pump with fresh clean oil in it would pull down to 5 microns. Next day we broke the vacuum with refrigerant and evacuated to 28" on our gauge set. Always put a new drier in the system before evacuation; not much sense trying to dry out the old drier. Larger field serviceable system we always also had a moisture indicator. Technicians that cut corners, had a lot of call backs, left a messy work site, and/or had customer complaints on their demeanor did not last long. Today in our area there is a drastic shortage of HVAC/Refrigeration technicians. Hard to understand why there is not a line out there for training programs to fill these $100K/year + jobs.

Ron

 

[LD1]

100k a year.....not in my area.

100k+ if you own your own van and build a business.

But working "for" someone else,.....$20-$25 if you are good and it's a good company.

Still not a bad living, but most of these outfits are smaller, maybe 10 guys. Heck even a company with 100 is small in terms of a job that will offer 401k +match, insurance that's affordable...etc.

More like a 40-50k job with lackluster benefits

 

[daugen]

Good thing they haven't, probably work out about as well as Ethanol in our fuel

yes, one of those debacles in our lifetime is enough, where politics and corporate money override engineering and science.