Please help, freezing refrig line in add-on cooling

[filterchanger]

thanks bwal,,,thats what i was trying to say

[losiho]

By a "cool day", I mean a temp between 25 - 30 degrees C (77 - 86 F). I'm from Melbourne Australia (no dingos here ). Those sort of temps are mild for summer. A "hot" day is anything over 36 degrees C (97F).

As for not using the a/c on these milder days, sometimes it's not an option. The Australian sun is hotter than in any other country I've experienced, and in a home with a lot of windows, the inside of the house will get hot and stuffy even when it's relatively mild outside.

[filterchanger]

i think you may need a new house,,when you get the new house and a/c make sure the system is charged properly and make sure there is enough airflow across the evaporator coil

[coolperfect]

Air out 54 room temp 75 take readings at unit if same or greater difference unit is not moving enough air.

[Wild Leg]

Originally posted by filterchanger
thanks bwal,,,thats what i was trying to say

It's easy for me.
I get to repeat it every day to a room full of wannabes.

[fat eddy]

OK, Here is your answer and it is the correct one. You have a restricted system probably at or very near to the metering device You could spend some time trying to resolve it but what you really need is a good repairman to get a look at it.

Hope this helps,

[Wild Leg]

Originally posted by fat eddy
OK, Here is your answer and it is the correct one. You have a restricted system probably at or very near to the metering device...

They already replaced the accurater with a TXV, then cranked it wide open.


You could spend some time trying to resolve it but what you really need is a good repairman to get a look at it.

This is the correct answer.


This guy is in one of the biggest cities in Australia.

Last I heard, Australia has goods AND services available.

He needs to

1) pick up the phonebook
2) Look under "contractors, HVAC"
2) pick up the phone
3) pick up his checkbook
4) Write the check


Problem solved.

[losiho]

Thank you so much for your oh so helpful advice. I've already had more than a few so-called techs out here and wasted money on labour charges on people who claim to be "experts" in HVAC after being "educated" in useless TAFE courses.

I don't think I mentioned anywhere in my posts that I am stingy or that money is a problem

[fat eddy]

I wasnn't trying to imply that you were stingy, if you want out of this situation without getting the correct diagnosis have someone install an auto reset freeze stat in combination with a min. off time delay on the suction line of the unit when the suction line starts to freeze it will turn the compressor off and let it warm again by the air passing over the coil.Another option is to have a hot gas bypass installed in the unit this will require another pipe to be run up to the unit, Oh yeah did I tell you that compressors below evaporators require some specific piping procedures.It doesn't sound like this has been considered in this case. Another idea is to have a thermo valve installed this a lot like a hot gas bypass but does not require an additional pipe to the coil, it will connect to the suction near the compressor and also to the liquid line and will inject hot gas into the suction to raise the pressure and meter liquid into the suction to keep the compressor cool. The more I read of your posts I become more certain that your system is restricted at some point and that restriction builds as it runs if this is the case then any of the options above will get you out of this nightmare. This is best advice I can give you being half a world away.

[beenthere]

You may have a restriction in the refrigerant circuit.
Or you may have a 5 ton unit, with 3.5 ton duct work.

Also an undercharged unit will do the same thing.
They should have checked the subcooling when they installed the txv.


The next time you call a contractor, explain everything that is happening, and tell them you want it fixed right, and your not worried about the cost, but when they tell you what needs done to fix it, they garranty that it will work right.

[Wild Leg]

Originally posted by losiho
Thank you so much for your oh so helpful advice. I've already had more than a few so-called techs out here and wasted money on labour charges on people who claim to be "experts" in HVAC after being "educated" in useless TAFE courses.

I don't think I mentioned anywhere in my posts that I am stingy or that money is a problem

I apologize for leading our conversation in that direction.
I am not usually quite so rude.
I certainly know better.

There ARE qualified people available.
The hard part is finding them.
That is what you will have to do.

It looks like TAFE is very limited in scope. (gritted teeth)
I could not find any type of curriculum guide online.
I would think there more comprehensive coursework is available, and that somebody in your area has the required skills to solve the problem(s).

It is certainly unfortunate that your experience with the industry has been negative.

Keep looking.
Contact the manufacturer(s), even if the equipment is out of warranty. They can give you some names of servicing dealers in your area.
Be sure you ask for the senior technician/mechanic, as you have already been treated to the other end of the spectrum.
Tell them the history.
That will scare most of the unqualified away.
Be sure you tell them you are not interested in a "quick fix" as yours will require much more time spent in troubleshooting.

I apologize again for my bad behavior.

Please post back with how you get this resolved.

[Edited by bwal2 on 02-14-2005 at 12:13 PM]

[Wild Leg]

How about type of filter used?

If you are using any type of high efficiency filter, then you have restricted the airflow.
Try changing to a cheap filter as an experiment.

You live in a cool, wet area.
Because of this, you need minimal cooling, but in order to maintain comfort, you need to dehumidify.

The tendency for years was to guess at what size equipment you need, then go the next size up. (Bigger is better theory.)
This is faulted by the need to control humidity as well as temperature.
A larger than necessary unit will cool the structure, then shut off, without proper dehumidification because a thermostat only senses temperature.

What you really need is a system that will stay running long enough to dehumidify, without overcooling.

Generally speaking, an undersized system is better at dehumidification.

I finally realized this was an add-on to an existing forced air furnace.
This means your duct system and indoor blower is sized for heating only.

If the duct system is not adequate for the cooling plant, you will get the symptoms you have described.

[bzzline]

Looking at these outdoor temps you may need to have your tech consider fan or pressure controls you may find on refrigeration units.
I work in South Georga with smaller HVAC residential units so I may be wrong about HPC.