Ductless mini-split for high-rise condo

5 years ago

I live in a southern exposure condo unit on the 19th floor in DC. This is an old building, with convector heating and cooling. The building cannot offer heat and AC at the same time, and must offer heat Oct-May each year. With my southern exposure and the heat being on in the fall/winter, it gets VERY hot inside. It's regularly in the 80s in my unit on sunny days all winter long, even with the blinds closed. I've tried fans, but they just push around warm air. There's no ability to put in central HVAC or a window AC unit, no ability to do any shading on exterior of buidling. And full blinds aren't cutting it.

So I've been considering a ductless mini-split. My condo is 1200 sq. ft--a big open living room/dining room/kitchen, a big master bedroom, and a small guest bed/office. I have a nice sized balcony, cement floor and ceiling, that I could have the exterior unit on, and then hopefully run to interior units in each of the three spaces.

My concerns are:

1. How noisy is the exterior unit? I can't have a noisy AC unit running or my neighbors will complain and I'll have spent all this money for something I can't use. I keep hearing they're quiet, but are they really that quiet outside too? Enough that you wouldn't consider it intrusive if you're standing 20-30 ft away in a busier part of DC?

2. Do they need any special sort of electrical work done? Or are these things that you can largely plug into your typical condo wall outlets?

3. Anyone have any ideas of price ranges for this in the DC area? For a three-interior-unit option, or just for a single or dual interior unit? I'm seeing ranges allll over the place, and the difference between a $3500 project and a $15000 project is make or break.

4. Anyone have any recommendations of service professionals for this in the DC area?

5. For those who have ductless mini splits, is there anything you wish someone had told you about them before you installed? Any unexpected benefits, or downsides?

Appreciate any help you can give. I've reached out to condo board to see if we're even allowed to do ductless mini-splits here, but proceeding on the assumption that it would be allowed until I hear otherwise.

Sort by:Oldest

Comments (9)

User
5 years ago
last modified: 5 years ago
Your association isn’t going to allow the building alterations needed in order to do this. And it likely doesn’t have the electrical power to run it.
kaseki
5 years ago
You might be able to put the compressor unit on the balcony, and then feed refrigerant to a unit on the inside wall abutting the balcony. Let it cool everything, or else you have to pay for more expander heads and the plumbing. Also the heads have to drain, and I will be happy to regale you with possible issues associated with doing so.

A few years ago (in NH) I had installed two Mitsubishi systems, one 4-head and one 2-head. Four of these heads are on interior walls. I think the price was near $20k to cool 2600 sq. ft. If you are only supplementing the building AC in the summer, and doing moderate cooling in the fall, you may not need a very powerful unit.

I can say that the compressors and the heads are very quiet. You can hear the fan at the outdoor compressor. It is about as loud as a window fan on low. At one point one compressor developed an intermittent racket, fixed by some adjustment, when the compressor iced up trying to pull heat from near freezing humid air. They are designed to de-ice, but I think between fan alignment and ice build-up there was a bit of overlap that needed to be adjusted.

You will need a hole in the wall to contain two refrigerant lines and a control power line. The lines to the compressor unit will be covered by a plastic cover. You will need an outdoor disconnect switch and power feed of 20 to 40 amperes at 240 Vac. Your balcony may be subject to a warm air breeze from the compressor unit, depending how it is placed.
Related Professionals
Bangor Home Remodeling · Vernal Home Remodeling · Toronto Home Remodeling · Port Saint Lucie Bathroom Remodelers · Altoona Bathroom Remodelers · Missoula Kitchen & Bathroom Designers · Chillicothe Bathroom Remodelers · Webster Bathroom Remodelers · Forrest City Kitchen Remodelers · Elizabethtown Kitchen Remodelers · Athens Interior Designers & Decorators · Pittsburgh Interior Designers & Decorators · Gary Home Remodeling · Barnstable Kitchen Remodelers · Palm Desert Kitchen Remodelers
kaseki
5 years ago
Unexpected downsides. You will need a yearly cleaning of both units, or every two years at most. These will cost a few hundred dollars depending on number of compressors and heads.
Elmer J Fudd
5 years ago
Re an HOA.... If another owner hasn't been allowed to do this, you should expect you won't be allowed to be the first.
wdccruise
5 years ago
I'd try a window film first. I have a large skylight and in the summer my DC condo heated up like an oven. I had external window film installed (I used external film because the skylight is way above the floor) and it made all the difference. Most films are installed on the inside of windows.
- 3M Residential Window Films
- Gila Heat Control Films
CHI_IL
5 years ago
last modified: 5 years ago
I'm in Chicago with the same situation as yours. We have similar sq.ft.

I'm on the 9th floor without balcony. Only 2 contractors are willing to do the work so far!

At first, I also want to do mini-split. One ceiling cassette for outside the bedroom and one wall unit in the bedroom, but one contractor suggested this system.

HVAC Unit: 18,000 BTU Single Zone Slim Ducted System

Indoor unit ARU18RLF

Outdoor unit AOU18RLFC

This is my plan. I'm still working with HOA to approve the plan.
Janet Koren
5 years ago
CHI_IL: How is it going with the HOA? how are the contractors going to mount the outdoor unit?
CHI_IL
5 years ago
Hi Janet, I consulted the HOA and they didn't object. However, I decide not to move forward with the project due to work uncertainty and window replacement project is expensive.

The contractor was going put the outdoor unit below kitchen window which is the closest spot next to the fire staircase. Contractor told me the control panel is on the top.

If you have any specific question, please let me know. If I can answer, I will.
Elliot Brown
5 years ago
Hello - I am interested in doing the same. It sounds like they can easily attach the outdoor compressor outside a window. What was the costing looking like?

Thank you!

- Elliot