Lowest outside temp to safely run my new AC

[kentalope]

Hi All,
I’m now here and hope that you can help me with some questions.

I just had a Heil H4A836GKD / FVM4X4800A installed in my home at the very end of March. A couple of weeks ago it was fairly warm for April in New England and our inside house temp was about 75 degrees. Outside temp was about 63-65 degrees. Because my wife has bad allergies and I was anxious to try out our new AC I decided to turn it on. It came on for about 3 minutes and then it turned off for about 2 minutes and then it came back on for about 5 seconds. This cycle of off for about 2 minutes and on for 5 seconds continued. I had my AC on but my house was getting warmer (my wife was baking). I went on the internet and what I read made it sound like it was cycling and the it was best for me to turn it off and call the company who installed the unit. So I turned it off and called the installer on Monday (this all happened Friday evening. It was by no means an emergency so I waited until Monday to call).

We were told they could come out in a week and a half to test it – this was a little annoying considering we had paid good money for this –but it is not the heat of the summer yet so I can be patient. They were supposed to come yesterday but they called and said it will be too cool for them to test because it is set up to not operate below a certain outside temperature (it was only about 60 degrees yesterday).

Here is where I am running into a wall. They either would not or could not provide me with the temperature below which the unit will not operate. They then they proceeded to tell me the day I tried to run it the unit it was probably too cool outside and that is why it would not run properly.

My question is, can anybody provide me with the temperature at which my AC will not run because it is too cool outside? And is it possible to lower this cut-off temperature if necessary? I ask because this could potentially be a problem for us because on sunny days our house can run 10 to 15 degrees hotter inside than outside and simply opening windows will not bring the inside temperature down to the outside temperature. Also as stated above my wife has bad allergies and one of the reasons we purchased the system was to try and keep the windows closed more to help ease her suffering. So it is conceivable that on a very sunny 70 degree day it could be 85 inside the house (that would be extreme but not beyond the realm of possibility). If we cannot run this AC at 65 degrees outside we could potentially have a system that does not fully meet our needs.

I have tried to find documentation for this system that would provide this information but have I have been unsuccessful.

Any help or guidance that you can provide is greatly appreciated.

Ken

[wahoo]

There are "cold weather" controls that can be added to most AC units which will allow them to operate in cooler weather. You need to discuss your concerns with the installing company and post back to us what they recommended. Commercial companies (like Banks) run their AC units during early spring all the time, so it's not an unusual request.:.02:

[BaldLoonie]

Most say below 55-60 is when you need the low ambient controls. I certainly run mine in the mid 60s out. I'll have to research what ICP says, big brother Carrier says 55.

[kentalope]

Thanks for the quick replies. It is very much appreciated.

When I spoke with the installer yesterday he also mentioned that the units are often shipped to them undercharged and that it may need to be charged. They were unable to determine if it was adequately charged at the time of installation due the low outside temperature (again it was March). He stated that when we get a day “warm enough” (I’m still unclear what warm enough equates to in degrees Fahrenheit) they could come evaluate the system and charge it if needed and this would most likely take care of the problem.

Does that sound reasonable?

I got the feeling he just wanted me off the phone and I don’t know if I should believe what he was telling me.

I want to believe him he came very highly recommended and on the day of the install everything went very well and his crew was very professional. I called yesterday and asked to speak to him personally (he is the owner of the business) because his assistant initially called to reschedule because it was too cool yesterday. They wanted to reschedule for tomorrow which seemed silly because tomorrows high looks to be very similar to yesterday’s high temp. I can’t keep rearranging my work schedule so I can be at home only to have them continually reschedule because it is too cool out. I just wanted to know when and how this would be fixed.

So at this point I am just trying to educate myself as much as I can because he seemed unwilling to help educate me with regard to exactly how the system should work and what my expectations should be.

I am still hopeful that it will all be taken care of fairly easily but I want to be as educated as I can just in case he is feeding me a line of BS.

Thanks.
Ken

[motoguy128]

Server Rooms and computer rooms run year round. I'm installing a regular 5 ton split system in a server room in a light commerical building (more similar to residential construction) that will have cooling load probably down to 0F or lower. We're putting in a Luxaire/York (vendor preference for price, warranty, parts and availbility) and adding a low ambeint kit. THe low ambient kit usually uses a pressure switch to cycle the condenser fan off when refrigerant pressure drops too low.

[BaldLoonie]

Units come charged for 15' of tubing. Most jobs are well more. So he should be back and check it when it gets above 70. Each spring, that's the first thing we do when it warms up.

[comfortdoc]

It is not unreasonable that they need to verify operation after it warms up outside.

It is also possible for the installer to provide controls that allow the unit to operate in lower ambients. If it is needed it may come at additional cost.

[catmanacman]

I would demand that the come out and check it ,sounds like it is cutting out on a low pressure switch ,if they cant make it work then maybe they should remove all the refrigerant and weight in a new charge .most decent techs can get the charge very close at 65 degees outside especialy if it is 75 inside.ill bet if it was a collect call they would be right out

[dan sw fl]

Does that sound reasonable?

I got the feeling he just wanted me off the phone and I don’t know if I should believe what he was telling me.

So at this point I am just trying to educate myself as much as I can because he seemed unwilling to help educate me with regard to exactly how the system should work and what my expectations should be.

... but I want to be as educated as I can just in case he is feeding me a line of BS.

Thanks.
Ken

Some light reading might help ...

Super heat and sub cool = charging principles ... PDF attached

[kentalope]

So it finally got warm enough for the installing company to come out and check out my system. It seems it is a faulty TX valve. It has to be ordered. It should be here next week.
It makes me feel a little better with regard to the owner basically telling me to clam down because it was most likely just too cool outside - WRONG it was (is) broken. Don't treat me like a child just fix it.
I'll let you all know when it is finally fixed.

[wahoo]

LOTS of bad foreign made TXV valves on units!!! Way too many IMO anyway!