- I live in New York City, and it gets hot/humid as balls here.
- I’m OCD about natural light, i.e. I hate blocking my windows with a huge/ugly air conditioner.
- I’m OCD about electrical efficiency, i.e. I hate paying to energize multiple huge/ugly air conditioners.
- I rent my apartment, so I can’t modify the structure by drilling into the outside brickwork. I can drill into studs so long as I patch it when I move out.
- I avidly seek to eliminate minor inconveniences no matter the cost or complexity, i.e. I’m OCD.
Mini split Air conditioners:
- Are about twice as power-efficient as their window-mounted counterparts on average.
- Are much quieter. Like, 1/10 the audible noise.
- Can also provide heat in the same blower.
- Are available in 120v up to around 14K BTU in cooling power, and 240v versions go well past 14K BTU.
- There exist products that can sum two separate 120v lines to create a single 240v line, so long as each line is on a different phase.
Mini split air conditioners:
- Require a dedicated, GFCI-protected power circuit. Usually around 20A.
- Like any exterior power feed, require an external disconnect box.
- There is only single-phase 120v power coming into my apartment.
- Require professional line preparation (evacuation, filling with refrigerant, tube bending and other things).
- Require the interior blower and external condensor connection to be within a specified length, e.g. 45ft.
- Require semi-permanent mounting of the interior blower.
- Require rugged permanent mounting of the exterior condensor.
- A mini-split A/C unit is 3x to 5x as expensive as a window unit of similar cooling capacity.
- 120v systems stop at 12K BTU cooling capacity.
A Non-Destructive Solution
After looking at everything, it seems like we can make a simple bracket for the A/C condensor, feed the refrigerant and power lines through a simple block set in the window frame, then run the lines along the ceiling to the blower. Might have to saw a medium hole (2 inches?) through one wall to pass the lines through.
Major design choices:
- S-shape bracket made of aluminum box-tubing, so it’s not crazy heavy as we wrangle the bracket with mounted condensor through the window frame.
- Bracket rests nearly all weight and vibration on the exterior brick wall and window sill.
- Bracket projects through the window frame and is held by a bar that presses against the load-bearing structure of the window frame itself.
- Adjustable feet on exterior bracket and retention bar.
Fusion 360 Project URL: https://a360.co/2XQMvrK
Making it happen
I measured a bunch of things:
- Window frame.
- Window sills, interior and exterior.
- Dimensions and weight of the A/C condensor.
- Locations of mounting holes, refrigerant and power lines on the A/C condensor.
- Required refrigerant line length to reach the blower where I’d like to mount it.
- Confirmed the 120v outlet to feed the A/C condensor is a 20A circuit, with no other significant loads plugged into it.
- Size of my bank account.