To answer your question directly and in very general terms, these units do work in many applications. They can be a bit noisier especially when you get into the larger sizes. However in your case, I suspect it may NOT provide the heating comfort you are hoping for.

I'm sure if you have browsed through the various HVAC forums, you know there are a lot of considerations and calculations that must be performed to determine the heating or cooling needs of a home. Not knowing anything about the size, configuration and materials of your home, I am being very GENERAL here and hope it helps.

Heat pumps are designed and sized for the COOLING needs of the home. The heating needs are then supplemented (added on) according to the heating requirements. Ducting, if sized and adjusted properly, serves to provide a more even distribution of the conditioned air. With the mini split even if it could do the job, the room where it is mounted will most likely be very hot and very noisy (fan on max)in an attempt to heat the further end of the house, if it even does so.

My personal honest opinion based on what I know so far about your location and description of your problem and home is, it won't do what you expect it to do. You may receive some conflicting opinions so I hope I'm not just adding to your confusion since I know you want to get the best bang for your buck.

What is your current type of heat? Duct in the soil, if properly installed, (deep enough, sized properly, etc.) can be the best way to go.

My seven indoor units mated with three outdoor units work great. I have Mitsubishi heat pumps. They are quiet. I've had them since January. I have 3, 9000 btu and 4, 6000 btu indoor units in a 2000 sq ft house.

They really do the job. Your climate is way different from mine.

Hi Maryland - thanks for your input and no, you are not adding to the confusion. We have a furnace right now that does not heat the master bedroom and office which is at the back of our house and it's cold in the winter time. It may not be the fault of the furnace because there is only one vent in each trying to heat two fairly large rooms.

Hi Ionized - The installer told us that we would need two heat pumps - one for the front and one for the back, each heat pump feeding two rooms - two bedrooms, one kitchen and one great room.
Do you know where the Mitsubishi is made from? Which climate or zone are you in?
Have you heard of Gree industries (airlux brand) made in Zhuhai China? The installer says that all name brands have components made from this company.
Also, did you install it yourself?
Thanks.

Sorry JayDee, I assumed you were looking to just add one large unit. If you're zoning, then you would be in a better position. Your installer is right about the components.

Ionized, you have quite a setup there.

I am loosing my mind or someone deleted my statement that I live on the (South) Gulf Coast! That is a very important part of many of my comments on house issues. It is obviously very hot and humid here. Your BC situation is so very different so I can't really speak the practical side of your heating issues.

No, I did not install it myself. I got a guy that's been teaching at the local trade school forever as far as the local installers go. He did not have much experience with minisplits and called in a collaborator for the job. They did a really nice job running the tubes and electrical through interior walls. The house is raised over an open crawl space so I don't have anything but the outdoor units visible outside. Now I have three whereas before I had two conventional two-ton compressors, one AH, with a gas furnace in the attic.

I mostly looked into Sanyo, Toshiba and Mitsubishi. They all have advantages and disadvantages wrt operating features. I do not know your climate so my main concern would be low temp heating performance. Here if you have enough cooling in a heat pump, you can not really run out of heat. One thing I have noticed, but don't understand is that the single minisplits are more efficient and better at low temp than the multi systems. There has to be an engineering explanation or they are just a year or two ahead with the single systems and the designs will trickle over with a delay.

Overall, we really like the system. It fits our lifestyle. We are out a lot, and the house has its original doors and walls intact. The inherent zoning feature should save us a lot of money over the years since we will have less expense for conditioning of rooms that are not occupied at different parts of the day and night.

My systems are mounted high on the walls. It was very cold for my area when we went into operation so it got a good test. One thing that I noticed is that the programming could be better for heating. The inside blowers go to slow mode when the temp approaches the set point. This makes them good ceiling heaters. (That seems pretty predictable. I've lived in homes in predominantly cooling climates with both supply and return located in the ceilings.) Bumping up the blower speed manually solved the problem. I suppose that the ceiling fan might have done the same thing.

One thing I am very glad that I did was to change the first plan to put the units at the head of the beds in a couple of rooms. I was actually concerned that the cool air would cascade down on heads at low blower speed. That might have been a problem, but it would have been even more annoying to have hot air on the face in the "winter".

Keep in mind that you can mix and match. If I had not gone entirely with minisplits, I would have had a regular forced-air system and installed one mini in the rear utility room. The duct to that area originated in the attic, ran vertically down a chase through the house and under 2/3 the length of the house to three registers in the floor in that room. It was a weak point to keep in a main system. The expense of mixing systems like that might depend on how capacity breaks down in choosing a "main".

Finding a good installer who is experienced with minisplits might be difficult.

Thank you Ionized for the details that you have provided. It seems like such a risky and expensive endeavor for us here. You are right about it being hard to find a good installer in the area because it's all so new. We might go down to the Seattle area and see if there are installers there that might have more experience. Right now, we are sitting on the fence as to whether to go continue with our high efficiency furnace or not. The brands that are promoted here are mostly Airlux, LG, and Samsung for the minisplits. Don't know why they haven't brought in the Sanyo or the Mitsubishi - maybe not climate adaptable for us? I know the Mitsubishi have had good reveiws.
If there is anyone from the West Coast with some input, I'd love to hear from you too.

lots of mechanical and electrical problems

I spent over $5000.00 on Samsung Heat Pump. I might as well flushed it down the toilet. It never worked from day 1. The dealer was on speed dial I had to call so often. He finally stopped selling Samsung products and I was left to deal with Samsung. They would not assist in finding out what was causing al the problems. It was noisy and defrosted more than heat. I finally got fed up and ripped it out and replaced it with a Fujitsu. What a difference - twice the heat and very quiet. You can't tell it is running its so quiet. If you are considering a heat pump don't waste your money on a Samsung.