ductless mini split heating and cooling

[frank]

I know lots of you have newer homes and was wondering if any of you have the ductless mini split systems for cooling and heating and what are your reviews on them. do you think they are better than the standard ducted system or less efficient and cost effective? thoughts?

 

[freedomatlast]

I know lots of you have newer homes and was wondering if any of you have the ductless mini split systems for cooling and heating and what are your reviews on them. do you think they are better than the standard ducted system or less efficient and cost effective? thoughts?

They are a reasonable option if you want to add heat or A/C and you don't already have ducts in the house or room. If you already have ducts, stick to a conventional system. Also, my experience is that these mini-splits, even the ones rated to -15 degrees F work better as air conditioners than they do as heaters when it gets extremely cold.

 

[38Chevy454]

I think they are good for a stand alone area. I have a mini split for my detached shop garage, a perfect application for one. The efficiency of the mini splits are claimed to be high, although whole house traditional HVAC are getting much better and not far behind.

 

[calmloki]

We have ducted gas furnace, 93% efficient, late 90's vintage in Oregon. No AC. Added mini-splits to add AC for the few days our house needs it. We have been very impressed over the last 3-4 years. The AC is a nice addition and heating cost is very comparable to the cost of running the gas heater, which surprised me. Noise level inside and out with variable speed units is quite acceptable. Two thumbs up from a moderate climate user.

 

[Bamaman]

Modern homes in the U.S. most often have forced air HVAC systems. Mini-split unit seem best for basements finished out or added on rooms. When you get into the multi head mini-splits, they get very expensive fast.

We live 10 miles out of town and no natural gas is available. My house has a large terminal electric heat pump outside the house with substantial under foundation air venting. My upstairs has a split electric heat pump system with the venting in the attic.

My downstairs master bedroom suite is at the end of the venting, and it isn't comfortable in the hot Southern sun. I just installed a Midea 10,000 btu U Shaped inverter air conditioner this week (Amazon.) The window pane lowers thru the a/c unit to within 4" of the bottom. It's quiet, efficient and half the cost of one small mini-split system.

I wouldn't hesitate to install a mini-split or two. But most American homes have too many rooms to where numerous mini-splits with multiple heads would be required. And remember that heat pumps are not the most efficient source of heating, especially in colder climates.

 

[dingo]

I have a 1100 sq. ft second home and I installed a mini- split system. The home was built on a slab and there was also no attic space to put duct work. It has 4 inside units ( one in each bdr , one in living rm. and one in the sunroom) It was more expensive but was really my only option since I did not want exposed duct work.

It is very efficient since there is no air loss due to ducts. Also, the power co gave a $800 rebate. I love that each room can be controlled by a remote device. No issues so far and it’s been about 7 years. This home is in middle Georgia which has mild winters.

 

[OldShooter]

We are building a house and the main part will have standard ducted HVAC. There is a guest bedroom over the garage, about 400sf. and the HVAC contractor recommended using a mini-split there due to the difficulty and length of duct needed to reach it. He says that they are by far the most efficient heaters because they are pumping the heat from outside, not creating it with electricity or flame.

He just built a new house for himself. He has heated (slab) floors and two or three mini-splits for AC and supplemental heat. So he is a believer.

 

[Franklin]

Hay Frank. I have a large 2 story house. There are 3 vented/ducted HVAC systems that cover the house. Basically 1 down and 2 up (all guest suits). I went in search of an alternative solution to having to run these units continuously when all I really wanted to air was a few rooms at a time. So, I purchased 4 mini splits (Mitsubishi). I am able to heat or cool the key rooms without running the whole HVAC system. I can turn the whole house off at nite and just keep the master bedroom mini split running, I hit the workout garage each morning and run the mini split for 1 hour, have guest over and have them run their own preference etc. Ive been very pleased with the performance and it has helped me keep the HVAC bill in check. They are easy to service as you just pop the plastic filter out and rinse. Yes, I thought this was overkill but now I rarely run my HVAC system.

 

[skyking1]

we are in a ~1300 sq ft manufactured super good cents home with central electric heat.
I self installed a pair of 12,000 BTU pioneer mini splits, and they heat the whole home for about 360 days of the year. The other 5 days I will run the furnace if it gets down to the 20's or colder. Anything above 30 F outdoors and they keep the house comfortable.
That is way undersize only 2 tons but it is enough. The power bill took a huge dive with that installation

 

[SnowballCamper]

A central air system controls humidity, as well as heat and cool. The mini-split does nothing for humidity. Depending on your location, that can be a big deal. Cool and clammy is not much fun IMHO.

 

[Masquernom]

A central air system controls humidity, as well as heat and cool. The mini-split does nothing for humidity. Depending on your location, that can be a big deal. Cool and clammy is not much fun IMHO.

I may be wrong, but I believe the mini-splits still require a drain line to the outside to drain away moisture that condenses on the cooling coil same as a central AC unit? So they should indeed lower a rooms humidity, though probably not as well as a central AC unit.

 

[OldShooter]

A central air system controls humidity, as well as heat and cool. The mini-split does nothing for humidity. Depending on your location, that can be a big deal. Cool and clammy is not much fun IMHO.

Even just a window AC reduces humidity in a house. Condensation is unavoidable if blowing warm moist air across a cooling coil. That's why the ACs and mini-splits have drain hoses. Whether that is enough for the house is probably a YMMV question, but the dehumidification is unavoidably more than "nothing."

 

[38Chevy454]

A central air system controls humidity, as well as heat and cool. The mini-split does nothing for humidity. Depending on your location, that can be a big deal. Cool and clammy is not much fun IMHO.

The mini split does reduce humidity. It has a condensation drip tray, just like a whole house type evaporator, and the condensate water is drained outside. The drain line typically runs with the refrigerant lineset and drains near the outside condenser unit.

 

[SnowballCamper]

I guess the drain in the rental I stayed in was plugged up or something... It was more like a swamp cooler.

 

[finnski1]

A central air system controls humidity, as well as heat and cool. The mini-split does nothing for humidity. Depending on your location, that can be a big deal. Cool and clammy is not much fun IMHO.

Mine not only controls humidity but does it very well. I often run it just in the "dry" mode and don't even need the A/C to run. Very efficient this way.

 

[Franklin]

Mine not only controls humidity but does it very well. I often run it just in the "dry" mode and don't even need the A/C to run. Very efficient this way.

+1

 

[skyking1]

Yeah they put out water out the drain just like any air conditioner. It's part of the process.

 

[rk911]

I know lots of you have newer homes and was wondering if any of you have the ductless mini split systems for cooling and heating and what are your reviews on them. do you think they are better than the standard ducted system or less efficient and cost effective? thoughts?

we remodeled what the previous homeowner considered a 3-season room (no insulation, a space heater salvaged from The Ark and single pane windows). we corrected all that and more including a ductless mini-split. it heats and cools as expected and desired and it's fairly quiet. the only issues we have is in really cold days and i mean really cold days...

- the unit will stop producing any meaningful heat, or
- the unit will go offline necessitating a power off/on cycle.

otherwise it meets our needs.

 

[Bamaman]

Our first house had a large natural gas furnace, but it wasn't quite large enough to heat and cool a 16 x 32 foot den.

We had a PTAC unit in the den that we only ran when we got home. It'd cool down that huge room in 5 minutes--and it saved us big on utilities. PTAC units are what many hotel rooms use.

If you can cut a hole in the wall, a metal jacket goes there. Slide the unit in and plug it in and you're up and running for about $750-850. It's a great unit for part time rooms and garages/workshops.

 

[frank]

I already have duct work and it seems kind of senseless to just not use them or remove them. I hear a lot about the mini split/s and was just curious about what all the commotion was. thanks for all the replies. my furnace and central air are getting old and will need replacement sooner rather than later, so just checking options. thanks again.

 

[Surewhitey]

We have lived in 2 opposing climates from 2011-15 with mini splits, CA and Mexico (Caribbean). I would not hesitate putting them in any home personally.

Plusses are zone control, saving electricity, very efficient due to no duct loss of energy & super easy installation (one hole in the exterior wall).

Negatives, maybe less efficient for humidity due to zone usage, but we never were uncomfortable in Mexico to my recollection. It definitely drained a bunch of water as it ran.

You shouldn't skimp on a 220v system that will run more efficiently. The 110v system is only for single room use, imo (think window unit).

Filters are super easy to clean too. No extra filters for sensitive noses that I know of, but again, no duct for collecting dust or pollen too. Also, think about the views of the line that will be used (exterior & 1 per unit). Multi units will have multi holes and lines. May not be clean looking on the outside.

They do run super quiet, so much so that you forget to turn them off...

 

[folivier]

I'm starting to see ads for mini splits that use ductwork to deliver the air, not sure if you can use your existing ductwork. That could be a game changer if they deliver the efficiency that mini splits do and conventional central air doesn't.

 

[GTFan]

Yeah I'm curious about that, the mini splits that use existing ductwork. These can be a direct replacement for an existing air handler/compressor combo, right? Anyone know of or have experience with those?

 

[ERD50]

I'm starting to see ads for mini splits that use ductwork to deliver the air, not sure if you can use your existing ductwork. That could be a game changer if they deliver the efficiency that mini splits do and conventional central air doesn't.

Can someone explain this? I keep hearing that mini-splits are more efficient (and not just to any supposed loss in the ducts, but that actual compressor efficiency). But I don't understand why this would be. They are air conditioners. Seems to me, a central air unit, generally being larger, should be able to incorporate those efficiency improvements even better.

Maybe they were originally designed for areas with high electric bills, so they focused on efficiency? I just don't get it.

-ERD50

 

[ERD50]

Yeah I'm curious about that, the mini splits that use existing ductwork. These can be a direct replacement for an existing air handler/compressor combo, right? Anyone know of or have experience with those?

I'm interested as well. My son bought a house that went through a major remodel/addition 20 some years ago, and it's kinda sketchy. They have a furnace in the garage (very unusual around here) that supplies part of the addition, but no AC on it. The furnace is 20+ years old, due for replacement, I (and his wife!) have mentioned replacing all that junk with a mini-split so they get the heat boost and AC with a mini-split. It might make sense to use some of the current ducting, that would need some tracing out that I have not done.

-ERD50