Dear Popville – Ductless A/C?

Photo by PoPville flickr user ekelly80

Dear PoPville,

My house has radiant heat and no A/C (and therefore no duct work), so my husband and I are considering adding a ductless split air conditioning system. We’re pretty early in the planning stages, so were wondering if anyone in PoPville has this type of system and could offer their opinion, would be able to steer us towards (or away from) a particular contractor, has any thoughts on the impact that ductless versus central A/C has on resale value, etc. Any info would be helpful. Thanks!

32 Comment

  • Go ductless — it makes so much more sense and works better if you’re not chopping up your interior. For a typical 2 story house, the upstairs handles 80% of the cooling load. It works much harder to pump air evenly through a full house than just the immediate floor. We put a larger unit in our attic for the upstairs and a smaller split in the basement for the first floor and basement. The upstairs unit will pull humidity from the whole house, requiring a lighter cooling load for downstairs. Not to mention — no ducts, just ceiling vents upstairs and floor vents downstairs (basement has one small duct).

    I haven’t heard good things about the space saver ducts, but maybe others can share their experiences (positive or negative).

  • Can’t speak for the good ol’ US of A but I spent a few years living in Asia and split AC (what I think you’re talking about) is *EVERYWHERE*. Makes perfect sense when you don’t want to put ductwork in as you’re running coolant lines of ~1/2″ dia. instead of 4, 6 or even 8″ ducts. I personally don’t think the newer, ceiling-mounted heat exchangers (basically a radiator with a fan) are very intrusive or loud. And you can probably mount them on the wall by the floor as easily as on the ceiling.

    • I forgot to mention that split AC is a MUCH better solution than blocking windows with window AC units. Window units were developed before split AC and I think people still use them for lower installation cost and cultural momentum. You’re better off over the long run with split AC or central air than window units.

  • It’s too bad there’s no way to just run chilled water through those old iron radiators during the summer months, and put fans in front of them to cool the room.

    • Condensation would probably prevent this

    • Physics/thermodynamics would probably prevent this. Cold doesn’t radiate. Heat does. When you leave the refrigerator door open, you’re not letting the cold out; you’re letting the heat in.

      • Wait, what? You’ve never heard of a fan coil unit? Or am I missing your point?

      • Note the post you’re responding to specifically described putting fans behind the “radiators” (now more accurately described as heat sinks). I don’t know how effective this would be but it doesn’t violate any physical laws. An air conditioner works in much the same way – a fan blows air across a cold condenser.

        You are correct that for heat no fans are necessary, due to radiation. But that’s true for cold also – even without fans a cold object in the room will reduce the temperature. I can’t speak to efficiency, however.

    • dt

      That might or might not affect the temperature (I’d think ceiling fans would be a better means of distributing any cooler air near the radiators, but still rather inefficient), but it would do squat for the humidity. I don’t know about you, but I use the AC as much to reduce humidity as to reduce temperature, if not more!

  • If I were buying a place I think I’d want to know the details of how this works (radiant heat is, I think, more commonly known). But anything that’s not window units is good with me.

  • We used Michael Bonsby to install our ductless split ac in our 2 story plus basement (3 levels total) rowhouse. It took 4 days and the company was fantastic to work with after an initial mistake on the estimate, which was honored to our benefit. We love it. One thing to consider in your planning, no matter what company you use, it is less expensive to install ac in the winter than in the summer.

    • jim_ed

      Thats really not true, in the least.

      If you have a company that’s a certified installer of a brand, they usually run pretty steep rebate programs on the equipment throughout the summer cooling season. you can go the manufacturers website and find out local installers who will all more than likely to participate in the programs.


      if you’re a riverboat gambler, you can buy the equipment online for a fraction of the cost and hire someone to install it. However, this will come with ZERO warranty from the manufacturer (despite what an online ad may claim) and you better hope it gets installed correctly.

      for a ductless system, I’m a big fan of the Mitsubishi Mr. Slim. Really high quality equipment, lasts forever, and cools well.

  • whatever way you go… please check out the Energy Star models. They rate all types of air conditioners, including split systems. The website is a bit convoluted… but to search for qualified models go to this page:

    You will need to do a search to pull up specific models. General information can be found here:

    • Wait, I thought there was a GAO report or something that basically concluded that Energy Star ratings were worthless.

  • I considered ductless but ultimately I was able to find an installer who was creative with routing the ducts and went with a normal unit–it wasn’t much more expensive than a ductless system in the end. I am so glad that I did, because ductless systems are unattractive and in my opinion don’t perform as well. You need to talk to 6-10 installers before you decide–there is a lot of variation. Also, this is the absolute worst time of year to purchase something like this–they are going to be backed up and you will pay top dollar.

  • I got a bunch of insane quotes for mini splits last year ($14,000+ for two zones and my house is only 950 SF). Decided to go with window units another summer until they come down. Let us know if you find anybody good.

    • houseintherear

      Got my 3 way split for $8500 installed from HD Johnson (3 years ago, was installed in mid-June). Got many quotes around the price you sited, though… prices vary a lot around here because ductless is a new-ish idea to the area.

  • I got a “high velocity” system installed through Sila (formerly Unique Indoor Comfort). Unit is on the roof. Most of the ducts are through the ceiling, with a few chases built in to closet corners. It was expensive (about $15K for my standard Wardman-style house, to include a duct in the basement), but it works very well. A little noisier than I would like, but I’m sensitive that way. Concur on the comment about waiting until next fall/winter to install to negotiate a better price, if you can live through another DC summer without it.

    • I got a high velocity system too, also from Sila. My experience matches yours almost to the letter. Very satisfied. The house is cool, no big ducts, the unit is on the roof so not taking up yard space or making noise out there. Also, they send me chocolates every holiday season!

    • ah

      OP should look into this possibility as well. High velocity systems are likely to be more efficient than split systems because they use traditional compressors, which are more efficient than lots of little ones around the house.

      It may not work because of the house configuration, but often you can put one unit on the top floor/roof to serve the upstairs (with all ducts in attic) and another in the basement to serve the first floor. Minimal cutting of walls and such in that case.

      • When I was looking into AC for my old huge rowhouse, it seemed that split systems were only worth it in condos or smaller houses.
        I have a high velocity system in my house, put in by Energy Systems, Inc. The ducts are very small and it does a better job than conventional AC at removing humidity. My system is not noisy at all, and that was one of my fears. I think it depends on the installation, and whether the installer placed the right sound attenuating gizmos right at the outlets.

  • houseintherear

    I *love* my ductless system. Got a 3 way split between 2 floors- one downstairs in main area (no interior walls) and one in each bedroom. It’s wonderful, and the electricity bill is always very low. I supplement the downstairs unit with an EdenPure heater when it’s under 25 degrees or so- if I did it again, I’d get a 4 way split and have 2 units downstairs. I cannot recommend it enough. The best part is being able to control where I heat and cool during the day and night- no wasted electricity/energy. The upkeep is minimal- just have to wash out the filters every couple of months (no cost for new filters).

    I went with HD Johnson (of DC), and they’re amazing. Have had the system for 3 1/2 years and haven’t had any service on it yet.

    Do it! Go ductless! Better for the world, and cheaper for you!! I sound like a commmmmercial!

  • Can someone explain a little bit how these work and are installed? The installation seems high for what looks almost like window units to install (fine, more trouble than window units to install) but isn’t it like cutting a hole in the house, inserting ductless unit, and then works somewhat like a window unit in terms of sucking hot air out. I’d love to know more about this system option.

  • fp here

    Ours isn’t technically a “ductless system” — it’s two entirely separate units — one main full sized unit with a SEER 18 rating in the attic, and a separate smaller split in the basement for the 1st floor. The ducts are acualy in the attic and tucked between basement joists.

    It works like a dream and is low cost to operate. Highly recommend.

  • I’ve mostly heard good things about them. They are all over Asia and Europe. I’ve even seen them used in newly constructed buildings. The only bad thing I have heard is that if poorly installed and/or maintained , you can end up with fluid leaks with indoor part of the unit. So I would be careful with the placement of those.

    I’m hoping to install them in 6 apartments if I can get over the installation costs. Other than the install, the outdoor condenser and multi-zone units are fairly reasonably priced. Mitsubishi supposedly had the best units at the time I looked. These days, I’m lucky to get 3 years out of a brand new $350 window unit so I’m always buying them and hate blocking out windows.

  • Is it possible (and affordable) to set up a mini-split system so that all zones can be controlled centrally? It’s great to be able to shut off zones I’m not using, but would be annoying to have to go down into the basement (say) to do so.

    Or even better, can I control the system through a web interface on an arbitrary device?

    • houseintherear

      They run on remote controls- my remotes work from across the house, but not sure whether they would work between floors.

    • ah

      In theory this can be done, but keep in mind that they operate off of a thermostat, and that needs to be where the unit is in order to sense the temperature.

  • Definitely Damron Heating and Cooling ([email protected]; 301-440-2221). Chris handles a lot of old DC homes, and was great; started and finished when he said he would, no unexpected costs or disappearing act. Everything works great, and he was really careful with our original trim and fixtures. He’s since installed a whole house system for my sister/BIL. Great guy.

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