When You KNOW Someone is REALLY FOS!

[dirtybuck]

In the high rise building where I live, maintenance has turned off the heat and switched it over to ac. Kinda sucks that we don't have the luxury of switching our thermostats back and forth to either ac or heat when needed, but this is life.

A few years ago, the thermostats in each apartment were taken out and replaced with a new energy saver (Honeywell). The lowest setting for ac is 70 and highest for heat is 72.

Some of the people that live here are already complaining to the assistant manger (she lives in the building) that their apartments are too cold. All she can tell them to do is set the temperature up higher or shut it off completely (she's also suggested to some to put on a sweater).

My across the hall neighbors (who are prepetual LIARS) were trying to feed me some line of BS earlier that the temperature in their apartment was something like 58-60, and they were able to see FROST on the vents. They could also feel cool air coming from the vents when the unit is off. I asked some other people that live on that side of the building how the temperature was in their apartments, and I was told by more than one with the windows open and ac off temperature was no lower than 65.

I know for a fact that when you have an individual unit is set too low, it can freeze up, and needs to be thawed out. But this is NOT the case.

The vent near the elevator does put out cold air, but I seriously doubt that it's lower than 68 at the most. The hallways have a tendency to get hot without some cooler air flowing through them from time to time.

So, just to suppress my curiosity, I'll ask some of you that deal with ac's and heaters. Is there ANY WAY possible that frost can be seen on an ac vent when it's this warm? I thought it had to be in an environment that's 32 or cooler.

 

[iheartmaytag]

I guess frost would be possible

It could occur on the vent itself, but the air coming out would have to be much colder that the 20 degree drop that an air conditioner is usually capable of.

I think you have a prevaricator on your hands.

Back in the 80's at Western Illinois University, Macomb the twin towers were not co-ed. Boys one tower, Girls the other. They had the policy that A/C was on until Oct 1st, and Heat was on until May 1st. One very cold September, temps had dropped to the 20s, the girls hung a banner out about the fifth floor window that read "Turn On the Heat or we Turn on the Boys."

They had heat within about 30 minutes.

 

[joe_in_philly]

I remember seeing a white mist coming out of the AC vents when the AC was low on FREON. The low level caused the evaporator to be too cold, and it cooled the air too much. That only lasted for a bit, as then ice built up on the evaporator, blocking the airflow and preventing any cooling from happening.

 

[cuffs054]

Dirty, kinda sounds like a chilled water/boiler system. If neighbors is seeing frost he might want to check his vision.

 

[washer111]

Having just stayed in a hotel with some positively ancient gear in it, including a Chilled Water/Hot Water room HVAC unit ("ducted") - 

 

You'll be lucky if you get to even temperatures well into 'too cold' with one of those systems. I've stayed there before, and on the top floor, that same system (with a revised control unit and vent layout) couldn't pull more than 77º, running all night. My assumption now was that the lobby unit was running and "sapping" all the performance, all they simply didn't adjust the flow valves correctly (Which were some sort of old Heimeier setup). 

 

This time around, the unit worked much better, it not being the middle of Summer, the the lobby unit being switched off. But I didn't know the temperature, as the thermostat on this unit could be set anywhere between "Hot -> Normal -> Cold." Thats right... LOL

 

 

 

[gusherb]

On cars and window A/C's? Yes, I've seen frost from those. They both can easily blow air at or near freezing. I've personally measured one of our cars to blow 28 degree air if I set the blower down low, but most don't let theirs get that cold before cutting out the compressor. This was a 2007 Saturn. (Ironically for blowing so cold it never performed that well on a hot day)

I've also measured a 12,000 BTU Electrolux made GE window unit to get down to 32 degrees, that sucker had impressive dehumidifying capabilities as a result.

As for central A/C systems and chilled water systems (usually found in commercial and high rise apartments), something is most likely wrong if the temp coming out of the registers is below 50 or so, or more specifically, if the delta T between return intake and supply is more then 20 degrees.

 

[retro-man]

On a very hot humid day I will get some condensation on the vent itself, but with the cold water chiller system you will never get frost on the vents. The water would have to be frozen solid and would not get through the pipes. They are FOS. lol