[cpot25]

Here in Chicago, we've had a couple days of extreme heat (for this area at least). It's been about 95 today and high 80s this weekend. I just moved into a new place (rental) that has a 16' A-Frame living room, 16' A-Frame bedroom and 12' flat ceiling 2nd bedroom/office. In the living room there are 2 28"x36" skylights with one facing east and one facing west on the A frame part of the ceiling. I've been running the AC non-stop and i haven't seen it below 77, no matter how long it runs. Currently, it's been running for 3 hours now and has dropped about 2.5 degrees. Earlier today, i turned on the unit when the thermostat hit 82.5 and for the next 4 hours i ran the AC and the temperature was 80. The thing is that it doesn't feel like 80 degrees, it's definitely not cool, but it seems like the reading may be off. It's a brand new thermostat that I bought at home depot as the apartment had a manual one before and I replaced with an Automatic.

I've been asking my landlord for something every week so I'm hesitating calling on this but can't last an entire summer with it being this hot and I'm sure the bill is going to be ridiculous.

I'm considering putting blinds on the skylights to reduce the heat that comes in the afternoon which I would assume would spread throughout the remainder of the apartment. Would that really make a difference?

Should I spend the $80 to get the system "charged" or call the landlord and tell him something is wrong?

Thanks for any help.

 

[cpot25]

So I actually kept a log tonight from 500 until 1030 on the temperature inside my apartment. During the day, I set the auto therm to 80 as it was going to be a 95 degree day in Chicago and I work from home, but had a few appointments for a few hours. I wasn't here all day, but I would imagine the AC ran the entire time I was gone and when I got home it was 80.5 in my apartment. I shut down the AC at around 2:30 to conserve energy/money and turned it on at 5:00 during the normal cycle. Here's the results:

5:00 - 83.5 inside / 88 outside
--5:30 -- 84 inside / 88 outside

6:00 - 83.5 inside / 88 outside

7:00 - 83.0 inside / 89 outside

8:00 - 82.0 inside / 87 outside

9:00 - 81.5 inside / 85 outside

10:00 81.5 inside / 84 outside

After 5 hours of continuous use, I was able to bring my AC down 3 degrees while the outside temperature dropped 4/5 degrees. Please tell me that I'm not crazy in this situation, right???

 

[Doc Holliday]

You're system should be cycling on and off roughly every 10-12 minutes as it should easily reach desired set point in those temps, if it is the correct sized system.

If you have a thermometer, even one you stick into a turkey, stick it into the supply vents and get the supply air temperature and do the same for the return grill. Come back with that info and we can further help you.

 

[cpot25]

When I checked last night, I did the test at one of the closer ones and it was high 50s and when I did one further away it was in the low 70s.

Landlord is having the HVAC guy come by tomorrow who said he probably just needs to put in some freon?! I guess we'll see if that works.

 

[Doc Holliday]

When I checked last night, I did the test at one of the closer ones and it was high 50s and when I did one further away it was in the low 70s.

Landlord is having the HVAC guy come by tomorrow who said he probably just needs to put in some freon?! I guess we'll see if that works.

Air doesn't get much if at all colder than high 50's on properly charged systems. Refigerant is not your problem.

I'd have the tech check for air leaks as you should not be giving up anywhere near 10 degrees let alone more than that from one register to another. You are losing air and gaining heat in the supply air before it makes it to the living space and that is your problem.

A duct (or more than one) is loose or has a hole in it or is crushed or the insulation is gone or something is wrong with the delivery of your air.

 

[cpot25]

Ok, thanks for your help Doc. I'll ask the tech to check that.

Thanks again for your help.

 

[cpot25]

Tech came by and added freon to the system and that's it. He said if it's warmer than 85 degrees outside that the AC will not turn off and will continuously run. I find this hard to believe considering my neighbor has his AC set at 74 and it turns off all the time where mine is set at 75 and it's still 81.5 in here and only dropped 1 degree since the guy added freon.

Do I have unreasonable expectations?

 

[Doc Holliday]

Did he check for air leaks? Did you tell him that you were losing over 10 degrees from one register to another?

A deaf dumb and blind five year old girl could come over and just "add freon." I think she just did.

 

[Doc Holliday]

I'd check the air temps at ALL registers again.

 

[cpot25]

Ok, ill check them out again and let you know.

 

[cpot25]

Ok, so here's what I got with a digital thermometer:

Living Room (2 vents): 65.6 and 64.9
Kitchen (1 vent): 63.3
2nd Bedroom (1 vent and 1 return): Vent 63.3 / Return 80.4
Bathroom: 63.3
Master Bedroom: 63.5
Master bath: 62.6

This is a one floor apartment on the top floor of a 3-flat. Current temperature inside is 82 and current temp outside is 92.

 

[gregzoll]

Shutting down the system after a few hours is not going to save anything. You need to set the thermostat at the desired temp, and let it run to pull the humidity out of the air. Once the humidity level is down, then the room will start cooling. Keep in mind, the system may not be sized for those kind of outside temps, and depending on the square footage, and a few other factors, it may never get down to below 74.

Start by blocking off any direct sunlight, either by using window film that reflects the sun, and allows light, and also use room fans to move air. Seal any air leaks, if windows leak really bad, use 3m window film kits to stop air flow, door sweeps, and weatherstripping around the door frame. Let the system run, if it has to run 6 hours straight to bring the temp down, so be it. My system has ran three hours straight when the temps get high, just to cool off the house a couple of degrees, due to no insulation in the walls. Once down, and stabilized, the temp stays around 72, and the system cycles like it should.

You are actually throwing money out the window shutting it down and starting back up. Best thing is, set for 78 if you feel comfortable with that temp, and leave it.

 

[Doc Holliday]

Ok, so here's what I got with a digital thermometer:

Living Room (2 vents): 65.6 and 64.9
Kitchen (1 vent): 63.3
2nd Bedroom (1 vent and 1 return): Vent 63.3 / Return 80.4
Bathroom: 63.3
Master Bedroom: 63.5
Master bath: 62.6

This is a one floor apartment on the top floor of a 3-flat. Current temperature inside is 82 and current temp outside is 92.

Well now the temps are much more even yet they are higher than the high 50's you said you had yesterday. That means that your system is now possibly overcharged. When you put too much refrigerant into a system you lose coil capacity as less evaporation (picking up of heat) is possible as there is too much liquid, hence superheat charging. Do you have a txv or a fixed orifice refrigerant metering device?

I don't know what to tell you any longer. I was thinking the same thing as what was posted above, close your windows with some curtains and have a heat loss analysis performed to assure that the system is the correct size for your place. And again, have all ductwork checked for air leaks/insulation problems.


This is going to be a constant headache until you put your foot down and demand results, you do have what is known as renter's right's.

Not to mention a system should not just have freon put into it, it should never leak period, so if you have a leak and refrigerant was needed than the leak needs to be fixed but you don't have a leak, you have an idiot hvac technician and landlord.


Sorry, but this stuff drives me batty.

 

[cpot25]

Doc and Greg, thanks for your tips. I was home at 11am so I put the thermostat at 75 since I was going to be gone for about 7 hours or so. When I left, the temp was 82.5 with the outside temp being in the n-hood of 85-89. When I got back home at around 7pm the temperature in the apartment was 80.5 with an outside temp in the 90s. So, after 8 hours I was able to get 2 degrees relief. This obviously didn't sit well with me and I called both the HVAC guy and landlord. Haven't heard back from either.

Is it true that when it's 85 or warmer outside, that the AC shouldn't shut off and will continuously run? My fear is that this HVAC guy may have been the one that installed the unit and is afraid to tell the landlord that it's not the right one for fear of losing his business. I may independently have an HVAC guy come from one of the bigger companies just to look at the place. Is that something that's offered?? I've never had to deal with HVAC systems before so I'm new to this game.

 

[Marty S.]

Systems are supposed to be able to maintain 75 degrees at design conditions. In my area cooling design temp is 95 and heating is -2F. Chicago gets the same weather we do but a day later.

 

[cpot25]

Does that mean when it's 95 outside the system should be able to maintain 75?

 

[Doc Holliday]

Does that mean when it's 95 outside the system should be able to maintain 75?

With ease.

 

[cpot25]

Very interesting. Looks like i'm going to Yelp! to look for an HVAC guy to look at the system.

I have been able to get it to 79.5 within the past hour, so another .5 degree! Almost time for the long-johns.

 

[Doc Holliday]

Very interesting. Looks like i'm going to Yelp! to look for an HVAC guy to look at the system.

I have been able to get it to 79.5 within the past hour, so another .5 degree! Almost time for the long-johns.

Now that's pretty funny, spot.

I'm in Houston, Tx and we get well over 100 degree days and MOST of our systems are in attics which get into the high 130's and all systems properly sized for the space in those temps can hold the home they are designed and sized for at 60 degrees without fail and without a struggle.

In no way should you be having this problem. A system is not designed to run all the time as that defeats energy efficiency altogether.

 

[cpot25]

Yup, I agree. Once my landlord gets back from vacationing in Ireland he's going to get an earful from me.

Thanks again for your help.