When to turn the A/C unit back on after a freeze-up?

[blurredvision]

I forgot to change the filter last month, and my central air unit froze up this morning. It's almost defrosted, just a very little amount of ice is still present in between the blades. Is it ok to go ahead and turn it back on now, or do I need to wait until it's completely dry?

It's hot as balls in this house right now (87 degrees F to be exact), and I'm sweating my ass off, so I'm a bit impatient. Thanks guys.

 

[BoomerD]

SHOULD be completely dry, or the moisture remaining will just freeze again...

 

[blurredvision]

Originally posted by: BoomerD
SHOULD be completely dry, or the moisture remaining will just freeze again...

Roger that, that's what I was kind of thinking....hence the question here. Thanks.

 

[Pepsi90919]

why don't you just bust out the hair dryer

 

[Rubycon]

If it has a fan only setting use that. It will melt the ice faster and dry the evaporator faster.

Remaining water will not freeze on the evaporator with sufficient airflow and load - the suction pressure will be sufficiently high with an 87F ambient to prevent frost on the evaporator on a properly charged and functioning unit.

EDIT: I see this is CAC. Yes place the fan/off/auto switch to on and set the cooling /heating switch to off. Alternatively if your thermostat doesn't have the fan switch (even T87F's should though) you can pull the 'stat and place a jumper wire from the R terminal to the G terminal to run the fan.

 

[jupiter57]

Originally posted by: Rubycon
If it has a fan only setting use that. It will melt the ice faster and dry the evaporator faster.

Remaining water will not freeze on the evaporator with sufficient airflow and load - the suction pressure will be sufficiently high with an 87F ambient to prevent frost on the evaporator on a properly charged and functioning unit.

EDIT: I see this is CAC. Yes place the fan/off/auto switch to on and set the cooling /heating switch to off. Alternatively if your thermostat doesn't have the fan switch (even T87F's should though) you can pull the 'stat and place a jumper wire from the R terminal to the G terminal to run the fan.

Couldn't have said it better myself!
Rubycon, You sound as though you have been in the Construction/Engineering business longer than I! (28 Years now) Either that or very inquisitive.
But I'm willing to bet that you are just plain brilliant.

 

[blurredvision]

Rubycon, the unit should be sufficiently charged and functioning, it's less than a year old. Thanks for the tip, I wish I would've known about just turning on the fan to help it dry quicker about 6-8 hours ago . Thanks guys, this is one of the things I love about these forums. Infinitely more useful than google could ever be.

 

[TheGizmo]

Originally posted by: jupiter57

Originally posted by: Rubycon
If it has a fan only setting use that. It will melt the ice faster and dry the evaporator faster.

Remaining water will not freeze on the evaporator with sufficient airflow and load - the suction pressure will be sufficiently high with an 87F ambient to prevent frost on the evaporator on a properly charged and functioning unit.

EDIT: I see this is CAC. Yes place the fan/off/auto switch to on and set the cooling /heating switch to off. Alternatively if your thermostat doesn't have the fan switch (even T87F's should though) you can pull the 'stat and place a jumper wire from the R terminal to the G terminal to run the fan.

Couldn't have said it better myself!
Rubycon, You sound as though you have been in the Construction/Engineering business longer than I! (28 Years now) Either that or very inquisitive.
But I'm willing to bet that you are just plain brilliant.

looks like you have an admirer rubycon

p.s. i got my 50 mW laser pointer and im working on setting up software for laser grafitti, although i feel this laser may not be 50mW since it won't ignite a match head, even after using a permanent marker to color the matchhead black. either way it should be good enough for grafitti

 

[Rubycon]

Originally posted by: TheGizmo

p.s. i got my 50 mW laser pointer and im working on setting up software for laser grafitti, although i feel this laser may not be 50mW since it won't ignite a match head, even after using a permanent marker to color the matchhead black. either way it should be good enough for grafitti

I don't know if 50mW will ignite a match - I've had a few 50mW heads in the past but never tried lighting matches with them. That power should pop dark colored balloons. When you're borderline with being able to light a match beam diameter is very important. If it's more than 1.5mm at 50mW match heads will probably not ignite. Bring that beam down with a simple convex lens and matches should ignite easily at the beam waist.


EDIT:

Thanks for the compliments guys.

Actually in my profession one doesn't have much of a second chance if something breaks - the show must go on. 400 miles offshore there are no supply houses. We do carry quite the variety of parts but improvisation whether it's in my music or mechanical flexibility - is key to keeping things running smoothly and people happy. I work with lots of folks in varied disciplines and trades and we all learn from each other. Kind of like this forum.

 

[AlienCraft]

Originally posted by: TheGizmo

Originally posted by: jupiter57

Originally posted by: Rubycon
If it has a fan only setting use that. It will melt the ice faster and dry the evaporator faster.

Remaining water will not freeze on the evaporator with sufficient airflow and load - the suction pressure will be sufficiently high with an 87F ambient to prevent frost on the evaporator on a properly charged and functioning unit.

EDIT: I see this is CAC. Yes place the fan/off/auto switch to on and set the cooling /heating switch to off. Alternatively if your thermostat doesn't have the fan switch (even T87F's should though) you can pull the 'stat and place a jumper wire from the R terminal to the G terminal to run the fan.

Couldn't have said it better myself!
Rubycon, You sound as though you have been in the Construction/Engineering business longer than I! (28 Years now) Either that or very inquisitive.
But I'm willing to bet that you are just plain brilliant.

looks like you have an admirer rubycon

She's hot when she talks like that....

 

[blurredvision]

Hey guys, another question. I spoke with my dad tonight, and he said that it was probably low on "gas" (this is electric, he said they don't use freon anymore, the unit it right at a year old), or that the exit line for the condensation was probably blocked. He also said that not changing the filter in a timely manner would not cause it to freeze up, which I was wondering if that was true or not.

I turned the fan on for an hour or so after I read the suggestion, and when it quit dripping, I turned the air back on. After about 30 minutes, I went to check everything, and it was, for the lack of a better term, pouring water. I turned it off and put buckets under to catch the water. I'm not sure if something is terribly wrong, or if the rest of the ice decided to melt off once I turned the air back on along with the fan. I'm letting it dry overnight, and will turn it back on in the morning. As I type this, it's not dripping whatsoever.

Unless you guys tell me not to turn it back when I get up in 7 hours, I'll give that a try, and see what it will do in the hour+ that it takes me before I leave for work. I have a small chihuahua that we're worried about leaving in the heat of the house, especially with it being in the 90's for the rest of the week.

I'm giving a call to the people that isntalled it first thing tomorrow to see what they say as well.

 

[Squisher]

Originally posted by: AlienCraft

Originally posted by: TheGizmo

Originally posted by: jupiter57

Originally posted by: Rubycon
If it has a fan only setting use that. It will melt the ice faster and dry the evaporator faster.

Remaining water will not freeze on the evaporator with sufficient airflow and load - the suction pressure will be sufficiently high with an 87F ambient to prevent frost on the evaporator on a properly charged and functioning unit.

EDIT: I see this is CAC. Yes place the fan/off/auto switch to on and set the cooling /heating switch to off. Alternatively if your thermostat doesn't have the fan switch (even T87F's should though) you can pull the 'stat and place a jumper wire from the R terminal to the G terminal to run the fan.

Couldn't have said it better myself!
Rubycon, You sound as though you have been in the Construction/Engineering business longer than I! (28 Years now) Either that or very inquisitive.
But I'm willing to bet that you are just plain brilliant.

looks like you have an admirer rubycon

She's hot when she talks like that....

:thumbsup:

 

[mrSHEiK124]

AC's been busted since Friday, this is the 4th time the compressor decides to just go bad in the 5 years we've had this unit, freakin piece of shit; if we power the A/C on it shorts out the whole house, but an A/C tech disconnected it and just ran the fan and it worked fine, part doesn't come in till Tuesday

 

[Rubycon]

Originally posted by: blurredvision
Hey guys, another question. I spoke with my dad tonight, and he said that it was probably low on "gas" (this is electric, he said they don't use freon anymore, the unit it right at a year old), or that the exit line for the condensation was probably blocked. He also said that not changing the filter in a timely manner would not cause it to freeze up, which I was wondering if that was true or not.

I turned the fan on for an hour or so after I read the suggestion, and when it quit dripping, I turned the air back on. After about 30 minutes, I went to check everything, and it was, for the lack of a better term, pouring water. I turned it off and put buckets under to catch the water. I'm not sure if something is terribly wrong, or if the rest of the ice decided to melt off once I turned the air back on along with the fan. I'm letting it dry overnight, and will turn it back on in the morning. As I type this, it's not dripping whatsoever.

Unless you guys tell me not to turn it back when I get up in 7 hours, I'll give that a try, and see what it will do in the hour+ that it takes me before I leave for work. I have a small chihuahua that we're worried about leaving in the heat of the house, especially with it being in the 90's for the rest of the week.

I'm giving a call to the people that isntalled it first thing tomorrow to see what they say as well.

A residential split system is most definitely going to have freon, puron, genetron, or whatever they call it now.

Reducing the airflow across the evaporator will reduce its temperature low enough that frost can form. This will often bring about several things - the most common scenario is lower airflow and icing and blocking of the coil. If the suction line run back to the compressor is short enough and a suction accumulator (most common on heat pump installs due to low ambient evaporator operation when in heat mode) is too small or not present - can cause slugging of the compressor. Slugging is where liquid refrigerant enters the suction side and can damage valves and pistons. Hermetic compressors (commonly called tin cans) on small residential units are fairly vulnerable to slugging. If your unit is newer and of high efficiency (high EER) it may have a rotary or swash plate type unit that may be resistant to this type of operation. Either way it's not recommended to run with insufficient airflow across an indoor evaporator!

If condensate escape line is incorrectly run (not enough downward slope and/or no P trap) and is on the suction side of the air handler the catch pan at the bottom of the coil can actually fill up with water and overflow creating a wet spot under the unit. If water gushes out of the line when the blower motor stops you definitely have this problem. An empty P trap can also cause this symptom temporarily until it fills. It's always good to add some condensate pan maintenance tabs PDF in this area (1-2 tabs / 3 months) to keep slime down. Lack of condensate removal is the biggest complaint generator in units mounted above living areas. (wet ceilings, drip complaints, ceiling tile that looks like prison food, etc.)

Originally posted by: mrSHEiK124
AC's been busted since Friday, this is the 4th time the compressor decides to just go bad in the 5 years we've had this unit, freakin piece of shit; if we power the A/C on it shorts out the whole house, but an A/C tech disconnected it and just ran the fan and it worked fine, part doesn't come in till Tuesday

Sounds like it may be time to have a qualified electrician check your power. Most CAC circuits are fairly hefty and tripping the SE main sounds like a fault right across the SCR terminals or a contactor issue. IR scanning of these areas when the unit is running can find faulty terminals and loose junctions. Heck I've seen lugs glowing orange before when they present an abnormally high resistance under load! Most definitely something that needs attention!

 

[FoBoT]

hose it off