How To Charge An Air Conditioner Low On Refrigerant Through The Suction Side

Alright, got a pretty old unit well got a unit low on freon.
You can see one of these energy
devices that turns off the AC on the front of the unit some of the electrical companies out here in California
hook these up so they can turn the
unit off at peak hours and than they pass on a little bit of uh… energy
savings to you, give you a cheaper rate on your
air conditioner. This one is actually
mounted on the service door.
Anyway I am gonna take this door off.
And I have got a unit that is low on freon.
It is not cooling so.
At least not cooling very good anyway.
Get into this and than
I’ll go downstairs
and turn the unit on
Get the door here. Put this off to the side. There we go. Let’s see what is going on here.
I am going to go ahead and get my
gauges set up here.
And than charge this up here.
My gauges are not in the best shape especially the high side so I am just going to be charging it up through the low side today.
It’s time for me to order some new gauges.
Right here is our service line hook up.
And what you want to do is make sure
the valve is off
up top here
on the low side and the high side. Ok
Now remove my schrader valve cap and listen for any kind of hissing.
To indicate if there is a leak.
And it seems Ok.
And it’s got these quick connect fittings. You always want to use these quick connect fittings.
You really want to wear gloves to but since i’m just going through the high
side. Not so bad I mean I’m just going through the low side. It is not so bad on the low side.
A little bit worse on the high side.
Ok now that the
line is hooked up there we want to make sure that we purge any air
from the lines.
And than I will go ahead and hook up the middle yellow line to our refrigerant can.
Up top here.
And again
got a
quick connect
up here. You don’t need a quick connect up here on the
middle line as much
because you can turn the refrigerant off here.
But anyway I have one on there so.
And were going to open our can of refrigerant here.
and this is R-22. Ok.
Here we go and than purge our line here
So I am just going to crack it.
Let a little bit of refrigerant out. And now we are ready to charge it. So I am just going to open it for a second and than go down and turn the unit on so we can charge it.
Yeah it feels like it is low so. Ok I am going to run downstairs.
Be right back.
Ok. So were on now. Everything is running good.
The fan motor is running.
The compressor has kicked on.
you can see this is showing like only ten pounds of pressure.
Not too good.
Definitely low on freon so.
Oh yeah. Sounds thirsty. So I was working in this unit yesterday
and noticed the air conditioner wasn’t cooling so I knew I needed to get up here today.
Get up here early before it gets hot.
Here is the accumulator and it is starting to get cold
It is cold about half way up
Anyway I am just going to be doing this one by feel
Because like I said my gauges
are kind of on their last leg.
Time to replace them.
See how loose that is I mean this could be tightend up but
also the needles are kind of bent and the caps
are starting to fall off
so time for some new gauges
but these are a cappilary tube system and
the nice thing about a capillary tube system is
it is a lot more forgiving than other systems
It can actually, you would have to actually really kind of try to
overcharge these
Anyway once it is nice and cold here on both sides of the accumulator than I know that it is going to be good. So I am just going to
Wait until this flashes nice and ice cold
And like I said if I
put a little bit of extra refrigerant in
it is going to be okay because it just holds it in the pot.
And the way the capillary tube system works is
It is a fixed orifice so
It only allows so much refrigerant through at a time
you know if you’re a little bit
overcharge it is not like it
lets more refrigerant through.
It just stores it here and lets it go through.
As long as you are only charging
with vapor.
you don’t want to flip your can over and
charge it with liquid because than the liquid might
stay in the lines
and can actually cause liquid slugging of the compressor
You can probably hear the refrigerant
going into the system
You can hear the change now as the pressures are starting to get
balanced and get more closer to where they
should you can
hear the sound difference less and less
refrigerant is being
suctioned in as it starts to climb.
We definitely have a leak somewhere. Possibly here at the schrader valve.
Which is where you usually get your leaks. You can kind of see some signs of moisture or oil right there. I am kind of guessing it is from the schrader valve. I will pop it off and take a peak inside the high side.
You can hear the pressure difference now of the refrigerant going in is a lot less than when we first did this. And it doesn’t seem to be leaking from the schrader valve so I will go ahead and tighten that back on.
What I have is a leak repair additive that I can add to the system because this one it has been good the whole summer. It hasn’t gone low on refrigerant or anything so it has just got a tiny micro leak in it somewhere. Those additives are kind of good for that as long as there is no moisture in the system. Ok and feeling my line it is still not cold. It is kind of warm. And we can check what our pressure is at here. I’ll try to get the camera to focus a little bit. There we go. We will go ahead and turn the hand valve off.
See where were at. Were at about about 40 pounds pressure there
and on the green dial were only at fifteen so
we got a ways to go. You can probably hear it I am going to turn it back on.
I hear a lot of people don’t like these Janitrolls to much, but
they are pretty easy to work on. Pretty simple.
Maybe I’ve just gotten used to them.
Been out here for a while so.
The kind of nice thing about only
charging through the low side.
If you are using the high side you can get
more of an accurate
reading of what your refrigerant levels are at
but the nice thing about only using
the low side
is it is actually
going to release less freon
into the air
into the atmosphere
when you purge the high side
it lets a lot more freon out
and you know the high side is your liquid side so when
you disconnect your hose after your finished
and you have to release that
freon that is left in the hose
all that liquid refrigerant is in there
your having to release all that
but this just going through the low side
it’s releasing a little bit less freon. I am sure some people disagree with me on that but that is Ok.
anyway when you work with refrigerant long enough you
probably will reach some day where your
gauges really are not working properly
and you are going to need to be able to charge the unit by feel
or by temperature
and the other way we can check this is
check for the fifteen to twenty degree split inside the unit at an incoming and an outgoing register.
I have a video on that if you want to see that I can put the link on this video.
Its starting to get there.
It is starting to feel a little colder down here. Alright.
Up on the roof top in
Palm Springs here.
Give you a little view around. Look around.
While this thing charges up here.
Pretty nice up on the
palm trees here.
My palm trees are due for some trimming.
Got a lot of dates on them.
Pretty good dates to.
I have snacked on a few.
If you look around you can see the mountains over there.
Its a nice cooler day.
It has actually cooled off out here now.
This Summer was a little bit milder.
I think the hottest it got was about one nineteen, something like that.
I remember a few days where it was a hundred and sixteen. Those were pretty warm.
but I have had other summers where it has hit as high as a hundred twenty seven degrees and
so this Summer was pretty mild.
I got away easy.
I went through and well
we preventative maintenanced
the heck out of our air conditioning units to make it a better summer so. We had a much better summer.
This can take some time.
There is a couple ways to speed the charge.
With the compressor being low on freon
the freon helps cool
the compressor and
with the compressor being low on freon the compressor starts to get pretty warm.
If you have an ice pack you can put that on top here and that can speed the charge. Or some really cold water so I have got some really cold water. And I am just going to pour it on here. Avoiding the electrical contacts obviously. And that helps speed the charge a little bit. Its starting to get there.
Ok, once I am all finished I will have to follow this up with that leak additive. To seal of any leaks here.
See this line down at the bottom of the compressor
kind of funny
it is actually a heater. It heats up the bottom of the compressor.
And that helps it when it first starts to be in kind of the right condition for starting the compressor.
Right here is a filter drier.
You can see the arrow
pointing this way.
On a heat pump the arrow will point both ways because a heat pump has
a reversing valve where it changes the direction
where as here the condensor is removing heat from the unit.
and at the evaporator it absorbs heat. On a heat pump it can switch to where you know the
evaporator was absorbing heat and the condensor giving off the heat
on a heat pump it can switch back to where now the condensor becomes the evaporator
And the evaporator becomes the condensor. They switch roles. So you can heat your unit with a heat pump or you can cool your unit. Heat pumps are a lot more sensitive about the charge.
Your charge needs to be a lot more accurate where as like I was telling you these units have capillary tubes so they are a lot more forgiving. It’s getting there. Drink a little water myself.
Give you another shot of Palm Springs here.
The mountains there.
There’s a tram that goes all the way to the top of the mountain up there. I guess there is like a cafe
stuff like that.
I’ve been out here like eight years
I still haven’t been up there.
Some day maybe.
Or not
A bird is snacking on some dates there. Happy campers. Alright see how we’re doing here. It’s getting there. It just takes a little time.
This unit seems to be in pretty good condition
for being twenty six years old. Still kicking. Still kicking out the cool air. Getting there.
This is an accumulator
it helps prevent liquid refrigerant from getting to the
compressor and slugging the pistons.
A lot of units these days don’t have these on them some of the heat pumps have them inside the unit.
These ones have been done outside. It seems they went to
some extra steps to preserve these units. This one doesn’t have it but on
some of these other ones they have got a like another safety device this one has been taken out like on the high side it’s got a little piston in it as a protective shut off.
See if one of the other units has it. I will show it to you here. This one no.
bring you over here as this takes a little time. Wow all these units are gone.
Looks like they took them out on this whole roof.
Maybe I am not going to get to show you.
Here is one. See right here this deal.
Not exactly sure what you call this exactly.
Maybe somebody else can tell me.
And exactly how it work i’m not
sure either i think it has just like a
piston that
cuts off the flow if something’s
wrong. If there is something wrong in the
Something a little bit more for me to learn about.
There is always more.
Anyway go back to our unit over there.
You can see these service mats.
You always want to do your
refrigerant work,
your air condition work, on the mats.
Especially if you are changing a fan motor or putting in a new unit. You don’t want to put any chunks in the built up roof material. Anyway it is getting colder. Were not there yet.
Disconnect box is over there.
Kind of funny story I heard of some places
where the disconnect
they had people stealing all the units. They were stealing air conditioning units.
Some rougher areas
have to do some drastic methods but anyway.
I heard about where they, what they did
was they bypassed the disconnnect
so that if you wanted to
turn off power to work on the unit you would have to go into the unit itself and
turn off the breaker.
It is sort of like an electric fence
I was thinking about it is kinda like having an electric fence
a deterent for people stealing units, stealing refrigerant, and
stealing the entire units.
and by having the power where you can’t
disconnect it
they were less likely to take those
and they were stealing the disconnects and all that kind of stuff too so
there is some rougher areas out there that call for some
drastic measures
not not the norm
but in those situations
people have to get creative.
Have to do something different if there is a
rough area. Alright it is getting nice and chilly now. Still got a little ways. Might put a little more water on the compressor here. Try and speed this up.
I can feel it flash alot, you know, after I put the water on.
And than I feel it right here. At the unit it just
seems like all of a sudden it draws a lot
more refrigerant in.
It’s starting to flash nice and cold now. We are almost there.
Now I don’t know if you can see it so much in the camera but you can start to see
a little bit of sweat on
on the line.
As this gets colder. Not completely there yet but we’re real close. This is the little high side line to the compressor.
You want to avoid
touching that especially on that end.
I mean back here
this part of it it is not so hot.
But right there it is really hot. I have burned my arm lots of times by accident. Touch that aghhh tshhh. Looks like not the best soldering job down there but definetely not the worst I’ve seen.
This kind of looks like a newer compressor to like this isn’t the original
compressor. I’m just guessing. Like it was replaced at some point. Augh yeah we’re getting nice and chilly.
Chilly, Chilli.
The final test again is going to be checking for the fifteen to twenty degree split inside.
But it’s gonna happen. I have done enough of these to know
the way it is. Were good now. Nice and chilly.
Can’t trust my gauges. They are just too old. I gotta get some new gauge heads. See how it is showing
twenty five
on the green dial.
Fifty on the pressure. Nice and cool today. Man, what a difference it makes. I think it is supposed to be like a high of 81 today, 85, I am not too sure, but it is nice now. Probably about seventy six degrees outside. If feels good. Nice day.
Ok, we are there now. Nice and chilly. So I am going to go ahead and turn off the line here. And than disconnect the line. Listen for any leaks there. And everything is Ok. And than
make sure we put our schrader valve cap back on.
That is like our second gate to keep the refrigerant in the system. I like to do them a quarter turn past tight with my pliers. Not to crazy, just crazy enough. So there we go.
We’re good there. Come up here,
and turn our refrigerant can off.
Disconnect our hoses.
Than we have to release the refrigerant
from the line. We don’t want to leave it
stored in there. Unless I was going to go and charge another unit right away which I am
So I am just going to go ahead and release it. There we go, and now its out. That one too. The middle one also.
Like I said if we had the high side hooked up than when we
release it you would
see it just shhh
spraying out like a white mist come out
a lot more refrigerant gets trapped
in that line.
And that’s kind of the advantage in only hooking up the high side (I meant low side).
really the more accurate method is to hook up the high side but anyway.
We are good here. Alright.
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I’ll see you out there.
Ok so here it is inside the unit. It has already dropped to
seventy five
I think that it started around seventy eight seventy nine.
Something like that.
And the air feels nice and cool coming out of the vent. Lets go back here to
where the evaporator is. The air handler right here.
And just like on the roof, the low side should be nice and chilly all the way to right here.
And it is. Nice and chilly.
You can see it. You can kind of see it starting to sweat. You can see on my finger. For a second
how it’s like moisture.
So that is why we have got the insulation here.
So oh it’s nice and chilly.Perfect see it there the moisture on my finger. There we go. We got our condensate drain. The drain vent
Right here alright. Good old hydronic supply lines.
Good to go.

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