Any HVAC techs here? Question

[Utahcryogenics]

At my new place my AC output seems to die off around 6pm. At first I just thought is was because the sun was hitting my unit outside during that time. Well yesterday I went outside to take a look and the lines coming out of the unit were all iced up and frozen. In the basements utility room I noticed that the rubber coating was pulled off one of the lines and that line was frozen too. The "hot" line wasnt hot at all either.

My brother mentioned that I could have dirty coils or low coolant. The house is 8 years old and is immaculate. Before we moved in I had all of the carpets and duct work cleaned and everything was squeeky clean through my ducts. The guy cut two holes in my duct work and cleaned out every inch of the outgoing and incoming ducts all the way to each vent. They were pretty clean to begin with, just a little dust, but now they are super clean. If the coils are using the same filter as the ducts are then I dont think they should be dirty. I just dont know.

What can I do? Should I try to remove the coils and see if they are dirty? I really want to avoid calling a repair man out at this time in the season because I know I am going to get hammered. Plus if it is something I can do, I would rather do it.

Any help is appreciated.

If any of you are service techs and would like to come out, I can pay you if the services arent through the roof. I would rather keep my money local and in the community.

Thank you in advance all.

 

[DOSS]

I used to do HVAC and the most common cause of that this early in the year is either your Air filter is dirty - Please tell me you have checked and replaced (if you have an ION filter clean it) - Or you are trying to get your house to like 55 degrees. Also make sure that your condenser isn't full of dirt and junk outside the house.. once it freezes up just turn on the fan and turn off the AC as your coils have probobly completely frozen up

Oh do you have an humidifyer on your system or in the house.. if you do.. turn it off those are for winter use not summer and the extra humidity can cause everything to freeze up...

 

[Utahcryogenics]

New filter. It is an Aprilaire High Efficiency type. It is almost as big as a Geo Metro too. Mirv 11

I am going to clean the condenser tonight. I dont recall it looking to bad but I will hit it with the hose. I imagine that everything on it is waterproof right (considering it is outside)?

 

[DOSS]

yep just hose it down.. don't try to spray the electrical box though it may not like it. If you have an air compressor you can also blow off your coils in the house too if you really think they may be dirty. if everything is clean and you have good flow then 99% chance you have a pressure issue either Overcharged or undercharged (and hopefully you don't have a unit that is too large for your house as well then you start getting into bigger problems obviously) and will need someone with gauges and gas to come out and check that (I don't have those anymore )

 

[Utahcryogenics]

My house is almost 4000 sq ft. I have all of the vents in the basement closed since I do not occupy any rooms down there. (It is 100% finished). The basement stays really cool on its own anyway. Is this a bad thing?

When we moved in I thought the unit itself looked a little small for a house this big, but like I said I just dont know jack about HVAC.

I will wash it tonight and see if that helps. I am going to try and take apart the unit inside to see what the coils look like. I just hope its easy to fix.


Thank you for the information. I really appreciate it.

 

[DOSS]

It is kinda funny.. it is better to have a smaller unit that one that is too big.. too big causes freezeups. I would personally open up some of the vents downstairs (this will also help push some of that cool air that is downstairs up the stairways and into the return air ducts).

Again what temp do you have it set to cool to? Do you have a humidifyer? a lot of newer houses have them now...

 

[Utahcryogenics]

I dont know if I have a humidifier, I dont think so. My inspection guy never mentioned one and neither did the hvac cleaning guys.

I have my temp set to 72º I may turn it up to 74º though. My wife sleeps days and works nights and she likes it cool.

 

[rholbrook]

If its not the filter, it could be that you don't have enough return air. Because you don't have enough air flowing across the coil, it will freeze up. Your coil that usually sits above your fan on you heater will also be froozen as well.

 

[Utahcryogenics]

Update: Here is the model numbers in case this helps.

Payne Model# PA10JA042-C (Condenser)

Tempstar International Product Corp Model # EPA48J22A1 (Indoor unit)

(My wife just told these to me as she just got home from work, hopefully those are correct).

 

[pfinder]

your lines are froze, what temp do you run it at?? i know i went to this house and they had the ac down to 63 and it would freeze up.. so we turned it off for the day to let it warm the lines and had them try it at 65 or 66 and they didnt have a problem since. sometimes during the day its ok to have it that cold but during the night right now its gets a lil colder still and it would cause it to freeze up.

 

[JoeT]

HVAC techs- How do I know if I have enough fresh air volume? I've closed off 2 out of 3 upstairs ducts and opened 2 more downstairs. I wanted to use all the cold air in my basement for a cooler upstairs. I'm just worried about putting too much strain on the fan from lack of input cfm. Any ideas/suggestions?

 

[DOSS]

HVAC techs- How do I know if I have enough fresh air volume? I've closed off 2 out of 3 upstairs ducts and opened 2 more downstairs. I wanted to use all the cold air in my basement for a cooler upstairs. I'm just worried about putting too much strain on the fan from lack of input cfm. Any ideas/suggestions?

you mean you closed off the air returns upstairs and opened up more downstairs? that will basically cause more cold air to go into the lower portion of your house than upstairs. IE you will have a larger volume of air that will come out of the cold air vents the nearer they are to the returns. All of the air that you are pushing into the upper portion of your house now has to displace the air up stairs and push it until it is downstairs = less efficient.

I suck at explaining these things - but you can get an air speed indicator and go to every vent and all of the returns do some math that I hated doing and figure it out.. most likely you are not putting a strain on the fan due to lack of volume but a strain due to the fact that it has to be on longer to cool your house

 

[Utahcryogenics]

UPDATE:

Took the unit apart, the coils are so clean you could literally eat off of them. It is an A coil set up and the inside is really clean as well. Not even dust.

I checked outside and the condenser isnt clogged, or blocked in anyway.

I then ran the system and checked for leaks with soapy water. Nothing that I could find.

The only thing that sounded odd to me is that after it runs for about 10 minutes I get a girgling sound at the coils and it sounds like it is in the copper inlet pipe. I am guessing it may be low on coolant and may need a recharge. I am hoping thats all it is.

I turned up the temperature in my house to 74 deg. too and hopefully that may help.

I am at a loss. I am going to call around and see what it costs to recharge my system. One of the members here gave me a number to call and I am going to try him first. If anyone can recommend a good local place too please do.

Thank you.

 

[TEAM FRED]

According to your model # You have a 3.5 ton condenser.
This means that you should have at least 14 standard supply registers fully open.
Hope this helps.

 

[Utahcryogenics]

According to your model # You have a 3.5 ton condenser.
This means that you should have at least 14 standard supply registers fully open.
Hope this helps.

Thank you. I will make sure I have at least that many open. I appreciate it.

 

[Shtmtlman]

I have been a tech for 20 years and i can tell you if your house is 4000sq ft. and you have 3.5 ton unit and no zoning the unit is to small, it will never keep up. There are other options such as zoning different areas, or the expensive part, upsizing your equipment unfortunately. Just to give you perspective, my house is 1800 sq ft. and i have a 3 ton unit that maintains 74 cooling in my single level home. You need at least a 5 ton with no zoning. The way to figure it roughly without a heat loss done is 400 cfm per ton. If you have a 3.5 ton you are at 1400 cfm wich is good for about 14 registers. I have 13 in my smaller home. Hope this helps.

 

[Utahcryogenics]

It does. My house is two levels and my wife and I only occupy the upper level. The basement stays cool on its own. We have opened all of the upper registers and a couple in the basement to total 14. I didnt count the small half sized bathroom registers though.

I am hoping this will help. Before I had everyone in the basement closed, and only about 9 open upstairs thinking that would cool the rooms we occupy better. It obviously doesnt. I am learning as I go.