Okay HVAC professionals (or home owners with experience), give me the straight dope on mini-split multi-head A/C units. I own a historic victorian home that has an updated hot water boiler and radiators for heat. There is no duct work in the home and no central air conditioning. The home is three stories not including the basement and it is roughly 4800 square feet. I need air conditioning and I have a plan…
For budget reasons, we cannot afford to do everything at once. My primary concerns are the 1st and 2nd floor. The 1st floor has a parlor, dining room, kitchen, family room, and a half-bath. The 2nd floor has the nursery/baby’s room, my home office, two bedrooms, and two bathrooms. My plan is to address the 2nd floor first considering that is where the baby’s room is located, my home office which I occupy 8+ hours a day, and our bedroom and a guest bedroom.
After meeting with a local HVAC pro who was recommendation from a friend, it seems our best option is to use mini-split multi-head A/C units for the 2nd floor. Due to the layout of the 2nd and 3rd floors if we wanted to go with a traditional duct system, per the HVAC pro, we’d have to a.) drop the central hallway ceiling on the 2nd floor to allow for a central duct that then branches to each room and b.) do some form of build-out on the 3rd floor for the air handler. And there would still be other challenges to solve even with these two things. As I’m not a big fan of lowering my ceiling height (10ft ceilings everywhere are a big plus for us) nor reconfiguring the layout of the 3rd floor AND it sounds like it would be adding a whole lot more expense to an already expensive proposition… we’re exploring the mini-splits.
So… are mini-splits really a quality solution? What are the pros/cons? What do I need to watch out for? What do I need to know that I don’t know I know already? Fight some ignorance people!
We are expecting to get the estimate next week that will put some dollars & cents around the proposed solution.
The big pro is just needing to run electricity and refrigerant line set to the room. This stuff can be threaded through walls and floors much easier than running ducts. Downside is having the wall mounted unit in the room.
AFAIK, Mitsubishi’s Mr. Slim / City Multi is still the 800 pound gorilla in this market. If the system is designed and installed properly, it’s quite good. It gets used a lot for retrofitting office buildings and hotels where running ducts isn’t practical.
I’m a fan of split systems. The wall units are not terribly obtrusive, require no ducts, and will not occupy your windows. If you want you can even conceal them in a soffet and add vents to make it look like fake central air.
The installation is not trivial; it will require punching large holes in your rooms to run dedicated power and refrigerant hoses. And you will need to dedicate some outside space for the outdoor unit, which usually sits atop a concrete pad.
I’ve been looking at mini-splits also, even though I don’t have the building constraints and can easily run duct work. You can get wall mounted condensers, which I am considering, due to the fact that my attic will be new construction and I can run mega-power and condensation drains and all that crap.
We had them on our house in Argentina , work really well. The big units can suck up a lot of power so you may need to watch what circuits they are on in the house
I’ve been thinking of installing a split-unit A/C in my bedroom so I don’t need to cool the whole house at night Are there any guidelines on if that provides any cost savings and how long it would take to recover the installation costs?
I haven’t looked at these in 10 years and I suspect there has been massive improvement.
Check noise levels. When I looked, it was equivalent to window/wall units. This may or may not be an issue for baby - will a constant sound soothe or agitate?
Since you are dealing with a pro, the following should be done for you: Do NOT cool the bath as much as the bedroom. Stepping out of a hot shower into a cooled room…
It’s all we ever installed in Mali, West Africa. Temps there routinely hit over 100F during the hot season, and the Panasonic splits we installed in all the houses kept up easily. The only drawback was the amperage draw because the houses weren’t set up for that sort of load. A big advantage is that you have individual room temperature control.
I am now in an apartment cooled by mini-splits.
I like them. I am sensitive to noise, but they have never bothered me.
There is about a 3 inch hole in the wall for the cooling lines.
Noise levels are a concern of mine. The tech we are talking to and online literature by the manufacturer’s all reference the low db levels of the units but it is still somewhat of a concern to me. Our baby is a pretty sound sleeper (so far) and is used to background noises. Still, if it rattles and clangs like a standard window unit… no bueno!
So the Mitsubishi’s are the industry leader? The provider we are working with is recommending the Lennox MS8 products. Naturally in heating/cooling I know the Lennox brand name but I don’t know if that is really a reliable manufacturer or if I should be looking at other manufacturers like Mitsubishi.
To the internet Batman! googles Mitsubishi mini-splits
Since we live in an urban neighborhood, I’m considering the wall-mount as well. For one, it gets it up off the ground. Secondly, I’m thinking that if they can be mounted higher up the wall it minimizes the risk of theft. My only concern here is vibration carrying through the walls.
The only noise is from the fan, which is no worse than any other fan: noisier on high speed, quieter on low. Unlike a window shaker, the compressor is remote from the air handler, so unless it’s right outside your window, it won’t be a problem. The air handler can be mounted anywhere. With remote control units, you can even mount it near ceiling level.
Good point on the separation of the compressor in a mini-split vs. the all-in-one window units. I’m assuming these will be mounted up high on our walls.
I’m not a big fan of the remote idea since we’ll have 3-4 compressors and 6-8 indoor units. That’s a lot of remotes. Haha. But it seems the only option for the Lennox systems. It looks like the Mitsubishi models may have a smart phone app, not sure yet if that allows you to control multiple units or not. It would be nice to find something that works with a wifi thermostat and smartphone app.
My parents house has them in some rooms. The noise level isn’t bad at all. It is a lot quieter than a regular window a/c unit.
What they did, was they mounted a holder for each unit’s remote under the unit or near the doorway to the room. My dad would keep his by the bed so he could adjust it at night.
Thank you everyone for the responses. I do feel better that I got overwhelmingly positive experiences with mini-splits. Being the internet, I fully expected to find out my kid will grow a 3rd eye and gills if I go the mini-split route.
I had one installed 3 years ago in the 2nd floor of a large Cape Cod style house (we could not get ducting from the first floor up to the second).
It was very quite and efficient. One thought- the unit we purchased was a dual unit, it was an AC and a heat pump! The heat pump was very efficient on moderately cold days when heat was needed up there. It was only a few bucks more than the AC only model. I highly recommend it.
That’s something I’ve been a little confused about. When looking at systems online, it seems they’re all dual units with both a heat pump and a/c. Having a newer high efficiency boiler and radiators, so far on the 2nd floor we’ve had no issues with getting good heat in the winter at a fairly reasonable cost considering the size of the house. But I was wondering how it would compare, perhaps for late Fall and we don’t quite want to switch over to running the boiler if this would be a lower cost heating option. Something else to talk to my provider about, thanks!
Mitsu is the biggest player. Don’t know about Lennox. Has to be Asian designed, built and re-branded though, as is Carrier. Variable Speed Compressors are available now (3 phase compressor with single phase to three phase VFD.) Very energy efficient. Just like everything else, Hi Efficiency = Higher upfront expense. Daikin and Fujitsu are good second bananas. Daikin just bought out Goodman/Coleman to get a strong American distribution base, so they seem to be in it for the long haul.
Try to avoid interior walls where the condensate has to be pumped away. Too many problems with any of the small condensate pumps. If you have to use a pump, try to get the condensate to a space big enough to use a regular A/C condensate pump such as a Little Giant or Beckett.
The wireless remotes are just fine. The temp sensor is not in the remote, it’s at the head unit and senses the returning air.
Noise is not an issue. Even the high speed is quiet.
Most are heat pumps, Cool only is available but you’ll probably do well to go the heat pump route. The only place we install cool only is computer and equipment rooms.
Yeah the heat option is nice to take the edge off a room and not have to get the whole heating system fired up. When not in the road I work out of my house, I have often considered getting a split unit for the office , would save having to chill the whole house during the day for just one room, and likewise in winter.
We had a unit which had a sensor in the remote , a " I feel " setting which would adjust the temp to where the remote was.
Obviously if the remote could not communicate with the wall unit it was of no use.
In one house we lived in in Kuala Lumpur, one of the split units directed its air down onto a tiled floor. The dog, after a walk, would come and flop out in a spread eagle fashion for max under belly and testicular contact with the chilled marble floor. ( well where his harbals used to be anyway)
