Central AC in prewar apts

where do you install the unit?

it cost us about 50k for the units (for 4 bedroom) and another 30-50k in hiding the pipes behind the walls/patching up.

We're doing a gut renovation--it will cost roughly 35K (but that's because we're already opening walls)

We are installing the air handler in a dropped ceiling in one bathroom.

We are installing the compressor in specially rebuilt window; with a cabinet around it on the interior and masonry work exterior to house the unit. (We're using the lower half of the window space in this particular room--an office--for the compressor; the upper half will have its own new tilt/turn window).

Because of prewar architectural logic, we decided not to put ducts through the apartment, so we'll have vents in 4 of 6 rooms. Our main goal was to eliminate the need to window AC units because we have good river views that we didn't want obstructed.

good luck. its a big job; but i hope worth it.

Gutrenovator, can ask you where are you installing the central AC. We are actually in the market for a 3 bdr pre war, and very much interested in installing central AC. But seems like most buildings do not allow for that.

d

oops, sorry.
Pardeza, the central AC has two components.

The AIR HANDLER can be installed in a closet or elsewhere within the apartment. We are dropping a very high ceiling in the bathroom to install this component. It is something like 2 x 3 x 4 ft. The duct work will be installed in a dropped ceiling in the bedroom corridor hallway--and ducts will lead to vents in the bedrooms, living and dining rooms. We didn't want to create too many extra soffits, or drop too many ceilings -- we want to preserve the prewar look as much as possible.

The COMPRESSOR was the trickier thing. Our coop board said we couldn't put this on the roof even though we are on the top floor (they didn't want the roof to be perforated). So, there is at least one company that makes a COMPRESSOR that can go in a window -- it has a grille facing the outside; Anyway, we are putting it in the bottom half of a window opening (we are installing all new windows anyway.). The cost is that we'll have less light in that room (the top half will still have a window); and one needs to be skillful at creating a nice cabinet so the compressor doesn't just jut into the room like an eyesore. I think (hope) we have a good cabinetry plan to deal with this.

The other thing to consider is the amount of electrical capacity you have in the apartment. Often prewar apts. have low amps; it can be costly to "bring up" amps from the basement to increase the load to support central AC. Fortunately we didn't have to do that.

Actually, pardeza, as I re-read your comment, it occurs to me that you were asking about the location of our building. Upper westside--morningside. I think the coop rules will vary building to building, though.

Yes, I was asking about the building location. As I said, we are having a hard time finding a building that will allow for this kind of work. BTW, could you share the specs on the system you are installing? better yet, who is your engineer/architect?

Is the compressor going on the window roughly the size of a typical through-the-wall AC? did you consider perforating the facade under the window or elsewhere instead of using part of the existing window opening?

Thanks!

The air handler is Carrier FB4B-036
The compressor is National Comfort Products #030-1010

The compressor is bigger than the through wall AC. You can look at the web sites for both units to get specs. We were not allowed to perforate the facade anywhere in the apartment. That is why we are using the existing clearance from the window.

Each building has its own fussy rules.

A few issues that could arise/that coops are concerned about:
--noise from the central unit (compressor); its probably not louder than a window unit, but there were complaints in our building about another neighbor whose central AC compressor faced the interior courtyard (and other apartments' windows)
--grille work on the outside of the compressor; if neighbors will have to look at the grille, they may complain about the grille color (that also happened in our building)
--facade issues: our building would not allow us to install the compressor in the front of the building (this is a common pre-war building rule)

Good luck...I'm sure that any architect familiar with prewar renovation will have an HVAC person to consult.

Gutrenovator: is this a particularly quiet model of air handler? Will you be building in sound insulation to the dropped ceiling where you are installing it? I assume you are concealing the pipes that run from the compressor to the handler in the dropped ceiling also? And how are you handling drainage -- into the bathroom plumbing? We are in the very early stages of planning a very similar system, with the window compressor set-up you describe as a backup plan. I have seen it done and it can look good, with the right fronts and a high window. But our first choice is a compressor on a rooftop adjacent to the apartment, with pipes coming in through a transom-type of opening in the window pane. I too am reluctant to drop ceilings and am considering exposed cylindrical ductwork, painted or unpainted (we are in a loft so it wouldn't look too out-of-character). Did you consider the ductless / Mr. Slim models, and if so why didn't you go with them? I myself prefer a more concealed system, but I'm curious. Thanks for your very informative posts.

Thanks Gutrenovator, very useful info.

Deepwoof:
I am actually not sure about the noise level in the air handler or compressor, but I guess that since the HVAC consultant knew it was for an apartment, he suggested something appropriate noise-wise (your question is good and will make me double-check on this before installation occurs...)

Yes, the entire system will be concealed. I'm guessing that drainage will be linked to bathroom plumbing, but again, this is a technical question we didn't ask.

We did consider ductless; the main problem was that you still need to have a compressor unit outside -- even though it is a smaller compressor than what is required for central AC, it still must vent to the outside. We were not allowed to make any perforations in the brickwork; even for the small tube involved in the ductless model. Also, since we are gut renovating, installing the duct work is not a problem... I am not thrilled about giving up ceiling height in the bathroom, but its the only logical place in our flat, and for some reason, the ceilings seem unusally high in that room -- they are actually the same height as the other rooms, but since the bathroom is a small room, the ceilings 'look' higher (9'6").
Hope this is helpful.

Hello Gutrenovator,
Just checking in to see if you've been happy with your central air system. We are getting ready to do something similar in our apartment.
Has the system performed to your satisfaction? How about the noise level?