Minisplit vs ducted heat pump

[barnee]

Which would you pick if you didn't have to do any duct chases for the heat pump?

I'm looking at systems and I think the design of my new detached garage would allow either without any framing changes. It would be a two zone mini-split or a ducted heat pump.

The benefit of the mini-split is that I'm trying to condition two rooms that are on separate floors connected by a staircase. Each space would have its own thermostat and would run somewhat independently.

The heat pump would have one thermostat and it might be difficult keeping both spaces comfortable. I don't want to get into adjusting dampers all the time.

I think the minisplit wins, but wanted to get other views.

 

[log man]

I'm with you on this decision

 

[Ohmthis]

Right now I won't sway you one way or the other, but look up "HVAC zone systems" you'll find out that you will be able to codition the two spaces with one conventional system. What are your goals for the systems? How long will you be running them? All of the time? Only when you are working? What is the area designed for? Do you have a budget in mind? I didn't see where you are from, but do you need capacity (heating) below 20*? There are a lot of options, we will give you the advice you need. Hope this stirs more questions!

 

[barnee]

Live outside DC, and it does get down in the 20's but not very often.

The two spaces are in a detached garage and are occasional use (hobby and hang out space), so my plan was to have the spaces minimally conditioned and then be able to ramp them up quickly. Most times only one of the spaces would be used.

Not to big of a fan of HVAC zone systems. Just a bunch of controls opening and closing dampers between two fighting thermostats. Seems too complicated for my use.

As I write this I'm more convinced that the only system that fits the bill is the mini-split.

 

[Ohmthis]

Don't sell a zoned system short. Designed correctly they are efficient and comfortable. I really like mini splits, but they have some cons too. They don't filter well, are not designed for quick recovery (if you choose to keep your shop at 50*, then want it to jump up to 62*, it will take some time. Maybe even hours), the air distribution can be lazy depending on unit, and they (indoor coils mostly) need to be cleaned along with the fan every 6 months to a year. They can be quite expensive, but have less labor to install. Again, I'm not trying to sway you one way or the other. I'm just trying to give you as much info as I can. Something you may be interested in are ducted mini splits, check them out.

 

[barnee]

Don't sell a zoned system short. Designed correctly they are efficient and comfortable. I really like mini splits, but they have some cons too. They don't filter well, are not designed for quick recovery (if you choose to keep your shop at 50*, then want it to jump up to 62*, it will take some time. Maybe even hours), the air distribution can be lazy depending on unit, and they (indoor coils mostly) need to be cleaned along with the fan every 6 months to a year. They can be quite expensive, but have less labor to install. Again, I'm not trying to sway you one way or the other. I'm just trying to give you as much info as I can. Something you may be interested in are ducted mini splits, check them out.

Thanks Ohmthis, I'm going to get quotes and might as well have them quote it both ways. Ill report back after I get some more info.

 

[Grizzly Guy]

Mini split gets my vote.

 

[Jackfre]

Many of the current mini-splits have wireless stats so you can anticipate and control the temps prior to arriving in the space. Ohm, I don't see how a ducted heat pump that is less efficient, which it will be, will bring up a temp faster than the same size, more efficient mshp. A gas furnace, yes, but not a ducted heat pump. Also, ductwork takes up room. I agree that mini-splits should be cleaned annually, depending upon use and environment, but the ducted unit would see the same air and conditions and require the same regimen. Zoning ductwork is pricey and in this application against a mini-split, not a positive point, imho. I'd go mshp

 

[yeldogt]

Have used both and will be using both in my new build -- the mini splits are great .. but given the choice between the two .. still like the ducted systems.

Mini's do work great when trying to heat/cool a single space with limited ductwork area. Many small additions and the second floor of cape cod style homes are well suited for mini use.

Don't rule out zoning -- done properly it works and can be a great way to go. I did a garage years ago using a NG heat pack -- all the equipment is outside.

You would have to figure the running costa of everything -- Do you have NG. What's the electric costs?

 

[LS6 Tommy]

You only have one option- the multi zone mini split. You can't share an air handler for living and garage space...

Dual mini splits are going to be much more efficient and reliable. I haven't seen a zoned ducted system that didn't freeze the evaporator coil at least once every summer except for top of the line systems with capacity control. IMO they're too spendy for a garage.

Tommy

 

[barnee]

You only have one option- the multi zone mini split. You can't share an air handler for living and garage space...

Dual mini splits are going to be much more efficient and reliable. I haven't seen a zoned ducted system that didn't freeze the evaporator coil at least once every summer except for top of the line systems with capacity control. IMO they're too spendy for a garage.

Tommy

For clarification both rooms are outside of the "garage" area. One is a first floor studio of 350 SF and the other is a second floor teen X-Box room of 350 square feet. They are connected via a staircase with no doors in between. New construction and modern insulation.

No NG, all electric

 

[PoorOwner]

Is it an wife's tale or propaganda the evap in bedroom can leak, releasing all freon (more than a single zone ) in a multi zone system causing suffocation of occupants?
Heard someone who doesn't like MS wrote that here before.

 

[LS6 Tommy]

Is it an wife's tale or propaganda the evap in bedroom can leak, releasing all freon (more than a single zone ) in a multi zone system causing suffocation of occupants?
Heard someone who doesn't like MS wrote that here before.

Wive's tale. It's no different than a total loss of charge at the evaporator on a standard ducted system. I don't think I've ever even heard of a report of such a documented thing.

Tommy

 

[theoldwizard1]

I am a BIG min-split fan, although it is not the BEST solution for all HVAC situations.

The only drawback I have heard, is there is no good way for the air handlers to handle dusty environments.

 

[Danster2]

I have a 42x32 with an upstairs area I'm turning into a man cave. I'm in Charles county MD so my weather is the same as yours. Just got estimates for mini split system with a ceiling cartridge and a wall unit for the downstairs. The est. was 10355.79...The price was consistent with 3 estimates within a hundred dollars. Originally My thoughts were that the mini-split system would be less. I can't go with traditional system because the downstairs of the garage is already finished....ugh...
P.s. I have a semi open stairway to the upstairs. Upstairs is 16x42 with 8' ceiling, downstairs has 11' ceiling...

 

[Richard Cranium]

We just install a heat pump and we are now trying to get the damper set so that the upstairs cools also

 

[yeldogt]

We used a packaged unit when we converted a garage into a small apartment at our place in SC. There was no good place for the equipment inside the building -- the unit worked very well -- we had a very good installer.

 

[davidlee]

I wanted to heat and cool my shop. The cost of a mini-split was 6k the cost of a ducted system (minimal duct work) was $3200. I went ducted and love it.
3.5 ton unit. Which ever you choose you will love it.

 

[finn]

I love the Mitsubishi mini split in my house but would never consider installing one in my shop, as the filtration capacity is woefully inadequate for a shop environment.

 

[barnee]

Finally got some companies to quote the system and all said that the ducted system would not work in my situation, mostly since the upstairs space would not cool properly since its open from the first floor to the second (no doors) and heat rises.

Ended up picking a Mitsubishi 3 zone system with an 18k unit upstairs and another in the garage, with a 12k unit in the studio. The upstairs unit is purposely oversized.

For our winters in VA and how I'm going to use the space they didn't feel the hyper heat units were necessary.

All fed from a 42K outdoor unit.