A/c Question - HVAC - Page 2 - DIY Chatroom Home Improvement Forum
Advertisement


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Like Tree9Likes
Reply
 
Thread Tools Search this Thread
Display Modes
Old 08-29-2020, 09:15 PM   #16
Member
 
Join Date: Nov 2019
Posts: 62
Rewards Points: 124
Default

Re: a/c question


Quote:
Originally Posted by roughneck View Post
No need to pull a vacuum. Youíd then have to reclaim the remaining refrigerant left in the system. Itís illegal to vent refrigerant into the air.
Have your friend check for leaks with the system still charged. If heís an HVAC tech he should have a leak detector.
Not to mention if you pull a vacuum on a system thatís leaking itíll pull non condensables into the system.
yep he will do what he has to. he did it for 40 years. if i had his info i would have emailed him last week. all i will do is stand there and watch and help when he yells for help will be like old time again. thanks
corvairbob65 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 08-29-2020, 09:26 PM   #17
Member
 
user_12345a's Avatar
 
Join Date: Nov 2014
Location: Canada
Posts: 12,464
Rewards Points: 86
Default

Re: a/c question


Quote:
well for one the general consensus here is i have to go thru a bunch of hoops to fix it. because it is 31 years old no local service shop will touch it without first putting in some kind of sealer. i have been down that road here with using a sealer or leak detector and the price of a new unit is just more than she can afford. so like i said i put in a window unit to get her thru the heat and to see if having one in the window would cool ther house as it has to not only cool the main floor but the basement because she has no door to the basement at this time.
A mini-split unit can cost as much as if not more than a central - need a air handler and condenser or if there's a furnace a condenser and coil.

The basic central can be fixed with off the shelf parts, the mini-split can not.

Regardless of if a mini-split is put in or central, it's not a diy install unless you invest in expensive tools.

The cheap ones with pre-charged lines you really should avoid like the plague. Can save a buck now but long term between higher risk of refrigerant leak and lack of parts/support, it will cost more.
__________________
I am not in the business of any trade I give advice on. I have non-professional hvac experience + good knowledge of theory. Attempt repairs at your own risk. Never jump out safeties - especially pressure switches - on a furnace for testing with fuel supply on; use a meter. Do not troubleshoot with live line voltage present unless there's no alternative.
user_12345a is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 08-29-2020, 09:33 PM   #18
Member
 
Join Date: Nov 2019
Posts: 62
Rewards Points: 124
Default

Re: a/c question


Quote:
Originally Posted by user_12345a View Post
A mini-split unit can cost as much as if not more than a central - need a air handler and condenser or if there's a furnace a condenser and coil.

The basic central can be fixed with off the shelf parts, the mini-split can not.

Regardless of if a mini-split is put in or central, it's not a diy install unless you invest in expensive tools.

The cheap ones with pre-charged lines you really should avoid like the plague. Can save a buck now but long term between higher risk of refrigerant leak and lack of parts/support, it will cost more.
yep some told me that already and not going down that road. have a guy stopping out next week and we will see if this one is worth fixing. if not we will tear it out and put in a new one. thanks
corvairbob65 is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 08-29-2020, 10:34 PM   #19
Member
 
Join Date: Nov 2014
Posts: 5,846
Rewards Points: 740
Default

Re: a/c question


Something to keep in mind, if you replace the equipment. You still need to locate the leak, if you don’t plan on changing the lineset. If you reuse the lineset and don’t verify where the leak is, you could quickly find out it was actually in one of the lines and now your brand new equipment leaks too.
roughneck is online now   Reply With Quote
Old 08-30-2020, 07:34 AM   #20
Member
 
Join Date: Nov 2019
Posts: 62
Rewards Points: 124
Default

Re: a/c question


Quote:
Originally Posted by roughneck View Post
Something to keep in mind, if you replace the equipment. You still need to locate the leak, if you donít plan on changing the lineset. If you reuse the lineset and donít verify where the leak is, you could quickly find out it was actually in one of the lines and now your brand new equipment leaks too.
yes sir. if i replace the unit i will replace the complete system. a coil lines condenser. the only think i will keep is the t/s on the wall and the wires to the furnace. i may keep the control wires to the condenser if we keep the same unit location if we move it then i go to work and move the power disconnect to the new location. but we will see how that goes. one thing i may build is a power supply to turn on the condenser outside so i do not have to start the furnace for testing. that way we can do the outside. thanks will let you guys know how it goes if he does this this year. at this point it will be in his corner.

just so you know where i worked we had 300 a/c units. those were chiller for keeping plastic cold for molding. i worked at a plastic company and he was the serviceman. so most of the time i did the repairs but i did not have the gages the company provided the tools. and i would do some recharging as these units had sight glasses on them like cars with the target in the glass for moisture. and low freon. anyway if it requires replacing i want it all new so as to not have to worry about the old lines leaking next. i think they may be the issue now as they run thru a block wall and i'm leaning on they may have rubbed the block and wore thru and now leaking. i could not check inside the blocks. i would have figured they would have made that hole larger and did a better job putting the lines thru it maybe in pvc but on the inside i saw where they patched the hold up to the lines. could not tell inside if they rubbed thru. thanks
corvairbob65 is offline   Reply With Quote
Old 08-30-2020, 07:38 AM   #21
Member
 
Join Date: Nov 2014
Posts: 5,846
Rewards Points: 740
Default

Re: a/c question


Quote:
one thing i may build is a power supply to turn on the condenser outside so i do not have to start the furnace for testing.
What do you mean? The furnace has to be on, for the blower to run, to be able to run the condenser.
roughneck is online now   Reply With Quote
Old 08-30-2020, 08:06 AM   #22
Member
 
sktn77a's Avatar
 
Join Date: May 2009
Location: Chapel Hill, NC
Posts: 648
Rewards Points: 1,026
Default

Re: a/c question


"You’d still need refrigeration type tools like a flair block, nitrogen and a vacuum pump.
Avoid the precharged linesets. The connectors tend to leak refrigerant."


The Mitsubishi Mr Cool DIY minisplits aren't cheap junk and don't require this specialized equipment. Everything is precharged and goes together pretty simple. I've not heard of the precharged linesets leaking, so I can't comment further (although I suspect this is a small incidence due to homeowner error).
sktn77a is online now   Reply With Quote
Old 08-30-2020, 08:23 AM   #23
Member
 
Join Date: Nov 2014
Posts: 5,846
Rewards Points: 740
Default

Re: a/c question


Quote:
Originally Posted by sktn77a View Post
"You’d still need refrigeration type tools like a flair block, nitrogen and a vacuum pump.
Avoid the precharged linesets. The connectors tend to leak refrigerant."


The Mitsubishi Mr Cool DIY minisplits aren't cheap junk and don't require this specialized equipment. Everything is precharged and goes together pretty simple. I've not heard of the precharged linesets leaking, so I can't comment further (although I suspect this is a small incidence due to homeowner error).
It’s not the lines themselves, but the connections. The majority of them have leaked, and it’s been well beyond a small incidence for residential equipment. Remoted ice machines also have used them as the equipment is critically charged. And have had many, many leaks there too. So many that some ice machine manufacturers have gone away from precharged linesets.
Not to mention you have an ugly coil of extra line to figure out what to do with. And if done wrong, it becomes a compressor killing oil trap.
roughneck is online now   Reply With Quote
Old 08-30-2020, 09:05 AM   #24
Member
 
Join Date: Nov 2019
Posts: 62
Rewards Points: 124
Default

Re: a/c question


Quote:
Originally Posted by roughneck View Post
What do you mean? The furnace has to be on, for the blower to run, to be able to run the condenser.
the furnace has to control the a/c not sending heat. but if we are outside i can connect the power supply to the a/c power and use it to power the control relay. transformer for those that can't figure that out i guess. other wise i have to either jumper wires on the furnace like i did yesterday and then the furnace blower turned on. older furnaces you could jumper the t/s and just run the a/c unit without running the blower or you have to just disconnect the blower. but while he is testing we do not have to run back and forth to set the t/s for run or off. i did that hundreds of time with those chillers so we could run the a/c pump and not the rest of the system running because they had water in them for chilling and that would run out the water lines. bet i can describe that
corvairbob65 is offline   Reply With Quote
Old 08-30-2020, 09:27 AM   #25
Member
 
Join Date: Nov 2014
Posts: 5,846
Rewards Points: 740
Default

Re: a/c question


I’m still not following. The air conditioner can’t “send heat” unless it’s a heat pump.
The transformer in the furnace powers the entire system. Thermostat, furnace and condenser. And you can’t run the condenser without the indoor blower running in the furnace.
The only power supply at the condenser is the high voltage.
If you plan on rigging up a separate 24V power supply at the condenser for testing, it’s really pointless as you need the furnace on and the blower motor running.
roughneck is online now   Reply With Quote
Old 08-30-2020, 09:48 AM   #26
Member
 
Join Date: Nov 2019
Posts: 62
Rewards Points: 124
Default

Re: a/c question


Quote:
Originally Posted by roughneck View Post
Iím still not following. The air conditioner canít ďsend heatĒ unless itís a heat pump.
The transformer in the furnace powers the entire system. Thermostat, furnace and condenser. And you canít run the condenser without the indoor blower running in the furnace.
The only power supply at the condenser is the high voltage.
If you plan on rigging up a separate 24V power supply at the condenser for testing, itís really pointless as you need the furnace on and the blower motor running.
i do not want to have to run the blower on the furnace just to test pressures outside. ther will be no reason to have to run in the house and out back and forth if he want to run the unit. by tapping the 240 volts at the unit i can start the compressor and he can test what he want to test.

i did not mean the furnace would be on heat. if he wants to do tests on the a coil and not have the aire blowing in his face he would unplug the blower but outside we can runt he unit there and not walk back and forth in and out of the house. all i have to do is put 24 volts to the control relay. i did that many times at work on the chillers. so we could run the compressor and not the water pumps. when you start one of those using the control panel you do not get an option to not run the water pump unless you disconnect the control relay. by just powering the compressor relay you bypass the control panel.

yesterday i had the a coil panel off and was spraying soap on the coil i had the blower running and the soap would not make a film strong enough to make bubbles i had to disconnect the blower so i could look for any bubbles.
corvairbob65 is offline   Reply With Quote
Old 08-30-2020, 10:05 AM   #27
Member
 
Join Date: Nov 2014
Posts: 5,846
Rewards Points: 740
Default

Re: a/c question


What kind of testing and diagnosis can be done without the blower running?
Are you taking about running the compressor with no blower running? That isn’t going to work, the unit needs a heat load. No airflow across the evaporator is going to make the pressures tank real quick. The unit will start to freeze up. There’s no testing to be done like that.
roughneck is online now   Reply With Quote
Old 08-30-2020, 10:10 AM   #28
Member
 
Join Date: Nov 2019
Posts: 62
Rewards Points: 124
Default

Re: a/c question


Quote:
Originally Posted by roughneck View Post
What kind of testing and diagnosis can be done without the blower running?
Are you taking about running the compressor with no blower running? That isnít going to work, the unit needs a heat load. No airflow across the evaporator is going to make the pressures tank real quick. The unit will start to freeze up. Thereís no testing to be done like that.
roughneck i don't know what to tell you the thing had no freon in it so it did not need that much air blowing over it. i was not testing and pressures at that time. you can't test for bubbles with the blower pushing the fluid off the connections. you said a few time to do a bubble test so tell me how you do it with a breeze blowing the film off the area your testing?
corvairbob65 is offline   Reply With Quote
Old 08-30-2020, 10:13 AM   #29
An old Tradesmen
 
Join Date: Oct 2008
Location: Somewhere
Posts: 39,274
Rewards Points: 116
Default

Re: a/c question


Leak checking with soap bubbles, the whole system has to be off.


However if your going to run the outdoor unit to check operating pressures. Then the indoor fan must be on to get proper operating pressures. Otherwise, all pressure readings will be lower than they should be.


Can't compare a fan coil connected to a chiller to a vapor compression central A/C system.
__________________
When posting in certain forums, knowing your location will help others give better feedback/advice/solutions to your questions.
beenthere is offline   Reply With Quote
Old 08-30-2020, 10:24 AM   #30
Member
 
Join Date: Nov 2014
Posts: 5,846
Rewards Points: 740
Default

Re: a/c question


Quote:
Originally Posted by corvairbob65 View Post
roughneck i don't know what to tell you the thing had no freon in it so it did not need that much air blowing over it. i was not testing and pressures at that time. you can't test for bubbles with the blower pushing the fluid off the connections. you said a few time to do a bubble test so tell me how you do it with a breeze blowing the film off the area your testing?
Two totally different topics.
The unit can be off for leak testing.
But to diagnose the refrigerant circuit, outdoor and indoor units must be running.
You can cause compressor damage without the blower running.
roughneck is online now   Reply With Quote
Sponsored Links
Advertisement
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





Top of Page | View New Posts