Thank you for the responses! Brian Knight ~ Our home is one level (on a slab) with three bedrooms. It will be an open floor plan, just over 2,000 sq.ft. When I said "relatively" air tight/energy efficient I was referring to our quest to balance efficiency with using healthy materials (not a fan of spray foam for example). We do want to be mindful of proper ventilation/air exchange and have looked into doing something like this (copied from http://homeenergypros.lbl.gov/group/1000homechallenge/forum/topics/panasonic-whisper-green-w-ductless-heat-pump?xg_source=activity): "Some minisplits may have a small ducted system. Dave Robinson, www.GreenEarthEquities.com buys foreclosed homes in central California that he renovates, using two,1 ton Fujitsu mini-splits. He ducts one to the bedrooms and bath with very limited ductwork located in the hall ceiling. The other unit is ductless, and conditions the living room and kitchen of the one-story ranch homes. There are significant cooling loads with lots of 100 degree weather. His approach of combining ducts and ductless results in simple systems and homes with low energy bills. Dave has case studies posted on his website." Reply by Dave Robinson on August 31, 2011 at 10:12am "To be more exact, we use one outside unit (2 ton is the smallest they make in this model - so we use it on everything). One inside unit is the conventional mini split high on the side wall in the main room ... the one that everyone associates with mini splits. The other inside unit is mounted on the ceiling at the mouth of the hallway & delivers air to all the rest of the rooms thru a small duct system that we mount on the existing ceiling of the hallway. So the unit and all the ducts are inside the envelope. Then new drywall is added, reducing the hallway height about 10 inches. We throw the factory filter away and allow a 20 x 30 filter grille right under the air handler to provide a lot more filter area as well as access to the unit without breaking the building envelope. You can see pics of this hybrid duct design at A Good Business? How Long? Plus Ducted MiniSplit Update (Click the right arrow on the photo in the center of the page and it will take you thru a few other slides from that webinar and you'll get to the Mini Split photos). You'll notice we use galvanized pipe. That, along with the oversized return keeps the static way down which is essential for efficiency on these units. This unit has now been in two years. The owner loves it. Zero problems. Has utility bills less than half of his neighbors. This job also used a Panasonic ERV. We mount the ERV very close to the return of the ducted system and in the pick-up area of the wall mounted unit so all fresh air is circulated by the main system with no additional equipment needed. It works well for us and we have adopted this as our main system. It's the one we specify every time unless we are keeping old equipment that's not too old or too over sized for after our renovation. You'll also notice that we mount the outside unit on the roof instead of on the ground. Lots of reasons." We are thinking this might work with our floor plan: Kirkhall ~ Thanks for sharing your personal experience. I have read more on the HVAC forum. My interest in posting here was to see if ductless mini-splits were at all a preferred choice by those building new homes versus just being used for retrofitting/new additions. Niteshadepromises ~ "Based on all my research the operating costs are pretty substantially lower which we're looking forward to and hopefully might offset the initially higher install cost." This is in line with what we are thinking too! Good luck with your build! David Cary ~ The tax credits are wonderful, however, there is that pesky problem of having to pay upfront. With some budget reworking, this may be possible. However, my concern relates to your comment, "But I'm not sure getting all fancy is worth it.... R20 net walls, good southern exposure with some thermal mass. You won't need that much heat and you shouldn't need a/c." We don't want to pay for more than we need. The difficulty for us has been determining what our need is when factoring in the passive solar. I also agree with: "I've thought about this a lot and I don't know how cold you get but if you have total control of design and southern exposure, your best bet is lots of solar planning, tight house with thick walls. Cover the windows well at night. Then put the money in PV. Code will require too much of minisplits to be cost effective." To satisfy code, what would your recommendation be for a thermostatically controlled system that is reasonably efficient and cost effective (presuming we could swing the PV)? With good solar planning, another viewpoint is to put in some baseboard heaters to satisfy code. Is this reasonable or silly? Dekeoboe ~ I'm interested to know what you chose and why? Flgargoyle ~ As our heating and cooling days are very similar, it's good to know that you think it's a viable option. Though it seems I'm in the minority, I don't really mind the look of the wall units. Maybe it's because I don't find vents and returns all that pretty! Lori in the NW ~ Thanks for your opinion ~ they certainly are not for everyone! This post was edited by daisyblue on Fri, Feb 22, 13 at 17:45

Mini Splits have been around for years++. What U hear about them are how incompetent installers install them. Try www.mitsubishicomfort.com/ the best ..they have some very good systems. Make sure you talk to a mitsubishi rep. not a hvac contractor first. asked the rep to refer U to one of there best contractors...thats the best way to "get it right" These are pricey products. But excellent. They have systems that have one outdoor sections and upto 8 indoor coils. As far as heating with hot air into one room this is not a solution. As far as concrete floors...thats what is horrible! I just finished redoing a floor. Replaced the entire house with Platon, and hardwood.

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.

Having had a Mit HP ductless in my vacation home, I have a few comments to share. The unit has its drawbacks such as air noise, certainly less than a thru the wall or window unit but more than a piped in diffuser from a central system. I found it to be a bit annoying but grew used to it. The other drawback was the constant air movement that some would perceive as a draft. With the air moving a properly sized unit should distribute the heat fairly well as the wall units discharge down and have an air sweep option. No doubt the elect baseboard will be the quietist more and comfortable for heating; however it comes at a cost (energy use over a HP) Another option if you are going to heat electrically is to consider electric radiant heat mats installed under the tile. This will keep the floors warm, at or below the cost of operating the baseboard but add 10X the comfort and would be supplemented with the fireplace. For AC you could still go with a ductless or quality through the wall unit. Here is a link that might be useful: one type of electric floor radiant