Hi everybody, first post here with a bit of background details on my apartment and situation.
I've been in my apartment for about seven years now and it came with a through the wall unit (Frigidaire FHA106M1T1), which always used a ton of power and appeared to be growing mold inside it. The landlord couldn't even remember if they had installed it themselves or not, because it was so long ago. Thinking it was from the late 80s or something (not digital at all), I bought a window AC unit (SPT WA-8011S) and had them remove the Frigidaire, which turned out to actually be manufactured in October 2003 (the side label was hidden in the sleeve).
My apartment is in NYC and was built in 1900. I have the only studio apartment in the building and as such, I have one window, which overlooks an alley and is my fire escape, so I can't legally put a window unit there, plus my security grate wouldn't close and there would be a potential theft issue.
My initial question is - right now I have the SPT WA-8011S window unit installed in the sleeve where the old Frigidaire unit was and it's insulated very well inside my apartment. I've done a lot of Googling and the majority of people say that it's not a good idea to install window units in sleeves, because there are vents on the sides of window units, but none of the posts I read really elaborated on how much free space, if any, these people had.
My window unit has 3.5" free on its left side vent, 4.5" free on its right side vent, and 3.5" free on the top vent. Is this sufficient for airflow within the sleeve, or will the heat still build up and prematurely kill my unit?
My landlord is okay with buying a new through-the-wall unit, but I don't like to bother them because they barely touch my rent, and all the through-the-wall units seem much less energy efficient than window units, so if I can use a 10.8 EER window unit in a sleeve safely, I'd prefer that, especially with NYC's electrical rates.
Having said all that, I don't know if 8,000 BTU is going to be enough for my apartment. The Frigidaire unit turned out to be 10,000 BTU, but had to basically be running on high 12 the entire time. Part of that may very well have been a complete lack of maintenance of the unit all these years, but my apartment window also overlooks an alley with poor air flow and the floor below me is a restaurant whose kitchen exit door to the alley is right below my own window, so I'm sure a lot of the heat is drafting up. My apartment is usually 15F hotter than outside during these spring/summer months if I don't have the AC on. But my apartment is also only 300 sq. feet (9 ft. ceilings), so I don't know how many BTU would be really appropriate given these special circumstances.
Thanks in advance for any insight you may be able to provide me.