Low Ambient Kit
This forum has helped me a lot in the last year. I intend to do a write up of my thermostat solutions to help others. Anyway....
I am in a condo building. Condenser just for my apartment on the roof, and fancoil in my closet. It is a 2 ton Bryant for my 1200 sqft apartment.
Anyway, when I run the AC, sometimes the outside temp might drop into the 60's, or maybe 50's at night. I am in Vermont so it is quite common to have 80;s during the day, and 60's or colder at night. I suffer from allergies so it is best to leave the AC on. Also outside noise sometimes makes it desirable to leave the AC on. I sometimes notice if I get up in the middle of the night, the AC is starting to freeze up. It basically makes a slight ticking noise. Not totally frozen, but starting. Only noticed this a couple times a year, but not sure if it is doing it more frequently since I don't always wake up. I think a rooftop AC might be more common to freeze up since it doesn't have the warmth of the ground to keep it warm. Just a guess though.
My question: Is it bad to run the system like this? Should I install a low ambient kit?? Other than the ability to run the AC in cold weather, does the low ambient kit buy me anything?? Longer life, especially given the long run from fan coil to roof (2 floors up), or does it matter??
Is the low ambient kit simply a heater?? Let me know what you guys think.
A low ambient kit will help you to get a longer life out of the compressor, then just leaving it get slugged with refrigerant from a frozen coil.
Is it more of a concern since the condenser is 2 floors above the fancoil, or it doesn't matter? I am really wondering how much it actually freezes up.
I'll fight the overwhelming urge to ask how much low ambient kits are installed.....
No more concern then if it was lower.
Just running it at low temps, is not good for it.
My opinion is that you need to know if your system has a TXV as a metering device? Best to have techincian to diagnose that, before you spent money on amibient kit. Make sure you have proper air flow too.
Originally Posted by smoss
My house unit runs in the 50 degrees to remove moisture. The outdoor unit has a 2 ton compresor with a 5 tons coil. Its head pressure never got above 170 PSIG even in the 90's degrees day (I am in SE texas). It does not have ambient kit.
I am no expert but I thought the low ambient kit helped the metering device to be more accurate at colder temps. It says in the manual not to operate my unit below 55 degrees unless modification is done. I assume they mean a low ambient kit.
I have a Bryant Legacy 2 ton unit. Model number 123R. It doens't say what kind of metering is used. Is the metering part of the unit or done external? I can have the tech look at it. It is working fine and doesn't ever freeze up totally. Always produces cold air and shuts off as normal. Never freezes up to the point where it is running and runnning with no air flow. Just sounds like it is starting to freeze sometimes. Ticking noise.
Only time it totally froze up was when it was new and not charged properly. I bought the guy back several times and he thought it was freezing because it was too cold out. I told him it was freezing when it was 85 outside!! He didn't believe me until I left it frozen and running and it was warm out. Then he finally re charged the system. That was two years ago. Has worked fine since.
I just thought the low ambient kit is good protection just in case outside temp drops and I don't notice it. It's very common to have 80's during day then 50's at night. On top of that my condo tends to stay warm since it is surrounded by other units. I see what a heat pump and cooling tower might be better in this situation....
Get the low ambient.
It can save your compressor from an early failure.
Take Beenthere's advice, Install a low ambient!
One other question, what is the temp you are maintaining in your condo?
I like it cold when I sleep. It is usually at 70 at night. That's with a ceiling fan above my bed going at meduium to high speed. 72 when I am up and home. Probably 75 when I am not home during the day.
Originally Posted by ascj
A little off topic, but after reading a lot of useful info on here, I think it is safe to say I am oversized. I have 2 tons of cooling for 1100 sq ft. The other apartments that don't have direct sun have 1.5 tons. My unit does face the lake (West facing). So it gets LOTS of light at the end of the day. Two very large sliding glass doors going out to the balcony let in lots of light and heat. I have since installed two large power awnings that block a lot of the sun when I am home. AC runs much much less of course. So now I am really oversized if I use the awnings. I can't use the awnings in the wind. Getting the perfect size AC must be a big pain for you guys. I guess variable speed should be the way to go for everyone.
Good thing it doesn't get really really huimid too often. If it does I might set it at 70 during the day. I get bad headaches when it is rainy and humid. I can keep the humidity level between 50-55% all summer. Probably a little high but not as bad as some that I have read about on here.
So I finally got around to calling up about a price on the low ambient kit. The guy asked me if I was getting the kit so that I could run it in winter. I told him even in summer sometimes I hear the unit making ticking sounds like it is freezing up. He said he doubts that would ever bother the unit.
He then said he needs to look up if I need a case heater?? I thought a low ambient kit simply slowed down the condensor fan to maintain proper pressure. Why would I need a heater??? Am I missing something? Maybe he thinks I have a heatpump or something?
Not sure why he thinks a crank case heater will help.
But, you might want your air flow checked.
If you think its frosting in the summer.
The only time I think it frosts up is in summer when outside temp is in the high 50's. Other than that, it is fine. It always happens when it is warm during the day, and I have the AC on, then go to bed. At night it might drop into the 50's. It's not like I am awake to shut off the AC or do anything about it. I just know there have been a few times I got up in the middle of the night and heard that ticking sound that tells me it's starting to freeze up. I wonder how many times it does this when I don't realize it. I usually keep the temp at 72 or 70 at night.
Originally Posted by beenthere
Maybe I'll take a pic of my return just so see what you guys think. The fan coil is in smal closet with one return. The return isn't directly attached to the fan coil. Just a hole in the side of the closet really. I'll take a pic later.