I own an apartment in New York City (Manhattan). This comes with a lot of benefits and a lot of drawbacks. In this case the situation is that our Coop board will not allow us to install a central A/C unit. I am happy to discuss the lack of reason involved in this but suffice to say that for now, this is not something that can be changed.

What I would like to do is use something like a networked set of Friedrich (or equivalent) window units (which we are allowed to install).
http://www.pcrichard.com/category/H...ioners/Window-Wall-Slide-Out-A-Cs/_/N-10wy0xa

Our MEP engineer has said the best course of action without being able to use a single central unit is to use 2 window units and a window "fan" to exhaust from one bedroom and "draw in" the cool air.

Now for the question... I want to query the group here about a solution that might allow me to turn the fan unit on (automatically) that I mention in coordination with the networked window units? Assume I will have a single thermostat that will control the 2 units and that as they are turned on by the call for cold air from the thermostat, I want the fan to automatically turn on and then off as the units are turned off.

Assume that home automation, wifi, hardwiring, etc. are all options.

Thank you for your help!

 

Do you really need to turn the fans on and off all the time? In my house we turn the AC on about April and turn them off in October.

I don't mind getting up and walking over to the AC twice a year. Do you really need to automate your task?

 

To make the system work effectively and efficiently, all the elements of the system need to turn on/off when the A/C units turn on/off. There will be 2 A/C units and a fan unit... it isn't reasonable to turn on and off each of these units without automation each and every time the call for cold air happens (temperature increases above the thermostat setting).

So, in short, yes. Make sense?

 

It seems to me all you have to do is connect to the fan or compressor wiring in one of the air conditioners and run a wire to the third fan.

 

You shouldn't have problem doing this looks like wifi would be the way to go. But I think the fan idea is going to be a little hard to do because you need to move the air both ways.
2 fans maybe better one to pull air in and one to push air out so the temp is the same in the whole rooms a fan at each end of the room.

 

It depends very much on the shape of the rooms whether one fan will be sufficient.
A good, hard throw into a long room with a door fairly far from the fan would work.
But every job is different. Every time, the shape of the rooms has to be considered.
Without knowing the shape of the rooms, we are guessing.

I've designed hundreds of central air conditioners with only one vent in each room. You just have to know how air moves with only one source. It isn't obvious, but it can be learned.

 

I don't understand the need for complexity. Why not let each unit control within its own "zone" and just let diffusion take care of mixing?

[edit] Yeah, what #12 just said.

 

Before concerning yourself with the fans I would see how well the window AC units mange on their own.

Natural convection will dictate that the cool dry air they produce will tend to stay low to the floor and flow out into the other rooms while the warmer air stays up at ceiling level and flows the opposite way back to the AC cooled rooms. Given that, there's a good chance you will not need any additional fan assistance to get reasonable cooling all over unless your place is fairly large like over 1000+ square feet of floor area and all the cooling has to come from one room. If so even then a small box or oscillating fan at floor level to push the cooler air out of the room would be sufficient to keep the air moving the right way out and into the room.

 

If you could draw and post a rough layout of your apartment and where the air conditioners will go, we can perhaps give you a better opinion about the fan.

 

I did something similar with X10 stuff about 20 years ago. But my window unit had mechanical control switches so I just had the temp all the way down, the fan Hi, and when the power was turned on and off it ran fine. I don't think you'll find unit's like that anymore.

You'll probably end up leaving that freestanding fan running though to keep things comfy.

 

Here is the layout in ... (ignore the comments about air handlers etc since that is no longer an option).
The space is about 1100 sq. ft.

I think I have a solution that may end up being better than what I was proposing... the thought is to have a hardwired thermostat on the fan so that when the temp rises above the desired setting the fan will come on and draw cool air into the room.

Still thinking through this though. Thanks for the comments/ideas.

 

The fan blowing air out serves no purpose other than to make you units work harder for nothing.

Window AC units don't draw air from outside and push it into the room. They just pull the air from the room cool it and send it back out.

Given the approximate floor space and AC unit placement I would recomend going with as big of BTU rated units as can be powered by your electrical sockets which for a 120 volt 20 amp circuit would be around 18,000 BTU's. Especially the kitchen one since that's in the largest open area.

 

Is there no ventilation system in place already? What do you do for heat? Perhaps you could utilize that to help move air around.

 

@tcmtech - Ok... interesting, I did not know that (always inside air). So you would say just nix the fan in the second bedroom and let convection take over?

@wayneh - No, it is building heat (steam)... so it is just convection heating. This is a pre-war building... built in 1926.

 

- Ok... interesting, I did not know that (always inside air). So you would say just nix the fan in the second bedroom and let convection take over?

Yes. That's what I would start with. At most use the fan to push air in and out of the bedroom so that unit is assisting the other one.

 

I'm not sure I like the venting of the A/C over the kitchen stove. Bedroom 1 or the LR might make more sense, if those windows are available.

 

@wayneh - As drawn it is 10 feet or so away... you are thinking that is not far enough?
The only other option is a unit in the living room and that would be unpleasant from a noise perspective.

Doug

 

I wouldn't want to work in my kitchen with an A/C just 10 feet away, if the air stream was directed right at me or my work surface. You might be able to direct the airflow off axis enough to get it out of your way, though. If you spend more time in your LR than in the kitchen, maybe it's no big deal. I suppose you could even turn it off for the short time that you need calm air in the kitchen.

 

That's a very difficult floor plan. I would think about (4) 6000 BTU units or a single condensor with Freon pipes to (4) air handlers...but I don't think you can mount a condensor in a NYC apartment building.
Those Freidrich A/C's in post #1 are famous for being quiet.

 

@#12 - The single condenser and air handler is what we want but the building won't approve it... unfortunate... and literally the first case my architect has seen in 20 years where a building summarily rejected the request with no way to resolve it...

The Friedrich units are able to be "chained" together and used with a single central thermostat... that would be nice and is likely the direction we will go.

The challenge with more units is that you loose more light (the only option is mounting them in a window)... this is really why we wanted the central system. In this case less is more but of course still being able to cool the apartment and not have it be too noisy.