I could've went with a central air/heat but opted to go ductless. No big ductwork in the basement and no resistance heat needed since they will heat in the negative zeros. That sold me.

The problem is getting the air to move through the house and usually one inside unit won't heat the whole house when it's colder. Having a second unit outside is a bonus so if one goes down, the still will be running.

They can also be quite expensive to buy and install by some contractors and some of them will try and keep ppl from buying them from lack of knowledge or don't like them.

You have to overcome the habits of the contractors. North America is the only place in the world that Heats & Cools by blowing air through tubes. Then again we have subsidized the inefficient energy industry for decades. The efficiency numbers for min-splits are correct. It will take time. Look at how many people comprise the "tube" industry.

Thanks for the responses everyone! I'm going to get one of these for my house.

toadman77: how about connecting multiple inside units with one outside unit? That may do the trick for you..

There is more maintenance with mini splits compared to conventional split systems.

• 30% saving in ducting heat loss [Greater efficiency depends on how leaky your ducts are and whether they are indoors or outdoors.]
• variable speed [This does not make them more efficient. It may increase comfort and may increase humidity control. the same goes for variable speed central split systems.]
• ability to only heat/cool rooms in use [This is of greatest use in poorly insulated homes where room to room heat transfer is comparable to heat transfer to outside the home envelope.]
• 350% efficiency: I read that these systems generate upto 3.5 units of heat for every unit of energy consumed [This is true for any heat pump.]

I have a Fujitsu and a mitibushi unit outside. When I purchased the mitibushi they didn't have the muti zone hyper heats. They also are quite a bit more then the single heads and getting two separate units got me two rebates doing it that way. I added the fugitsu this fall. I figure I try the best two units on the market.

We're you heating with it and are you in a very cold climate? If you are look into eithet the mitibushi hyper heats (-13 for heating) or the fugitsu halcyon (-15 for heating ).

Thanks again toadman77. I'm in Wash DC, moderately cold winters.

Do you mind sharing how much your electric bill runs in peak winter, and how large of a space is being heated?

I have about 1000 sq ft ranch house. My electric usage for last Oct- May was 6000 kw ( guessing around 4500 kw were for heating). That would average around $450 in heating . I'm southwest of Pittsburgh. It should be a little more this year running two units but I'm adding a thermostat to my mitibushi unit which should help it from short cycling and saving money.

My wall mounted unit is on the center wall in the living room. When out got really cold the unit didn't keep the kitchen or dining room warm so I added a floor mount in the dining room to blow air into the kitchen. I use a floor fan for my bedroom to push the cold air out into the living room.

Your not far away so it wouldn't hurt getting one of those cold weather units. They have single and muti head units and they come in wall, floor, ceiling, and ducted versions. Brand wise Mitsubishi is a little more expensive and air condition better and the fugitsu are a little cheaper and heat better. Here's a nice writeup on how to mini split.

http://www.greenbuildingadvisor.com/articles/dept/musings/how-buy-ductless-minisplit

The other thing to look at is the minimum btus the unit produces. My Mitsubishi puts out 7500 minimum btus and varies on each single head unit while all the fugitsu single heads units are a minimum 3100 btus on the cold weather ones.

At 2200 sq ft in the foothills of the Sierra I have two Fujistu's. A 12 RLS (25 seer/12 hspf) and a 15 RLS2 (21 seer/12hspf) on the first floor. I have a dual in the upstairs bedrooms which I have never run for heat and do cooling only with them. To run the whole place, lights, H/C, well, irrigation and everything my highest summer/winter elec. bill has been $85.

The place to start an evaluation of the change is to decide if your current duct system can support new equipment. Respectively, Ionized and I disagree on whether inside or outside ducting loss varies in its affect on comfort. My view is that it is not enough to "give" a poorly designed and installed old or new system a bye, especially when there are now the alternatives of efficient mshp's. Your first step is a duct system pressure test. Then you must understand the cost to seal up the duct system. It can be substantial. 2015 Code says max of 6% leakage for new or old duct systems. If you have an excellent duct system you can then buy and install one of the hi-eff central systems. Duct leakage is creating problems for the two stage and variable speed central systems. Between your comfort and the high eff system is a poorly f[performing duct system. In other words, they can put all the technology they can come up with in the box. They simply can't deliver it. It is a real problem for the unitary manuf.

I pulled my entire duct system out of my house and went with a combination of mini-splits and a Rinnai Energysaver, a gas fired direct vent wall furnace (heat only). My propane consumption for the Energysaver, gas range and Rinnai tankless is 275 gal of LP/year. I've used the Energysavers in my home for the last 25 years with excellent results heating home basements and garages. Oh, by the way, by eliminating the ducting i gained two closets on the first floor and storage under the staircase.

A sketch of your house would be useful in advising. We can all take a crack at it then.

Toadman, I don't understand your short cycling problem. Your variable speed mini splits should not cycle at all in all by the mildest weather. They should be modulating their output. Keep in mind that variable speed equipment probably runs at its best at less than full capacity. If they come on and run harder and then shut off, you electricity bills could increase as a result.

jackfre, there's something else going on with your house. My location is a more coastal but still warm location (as a PGE customer), the only time my electricity is under $75 is when I'm out of town. I have no AC at the present time (but will be installing it in the coming months). My PGE statement says I'm in the top 20 % of low energy use for houses my size. Your numbers don't make sense to me.

In my area, for conventional systems, most prospective buyers don't care if a house has an 80 % or a 95% furnace, as an example. They don't care about efficiency. If they don't like what's there, it can be replaced. They care if the system works and move on to more appearance related features.

To me, second homes, mountain cabins, vacation homes, etc, are one thing. For those who have a main house at the average or better scale, things like wall heaters and minisplit wall units are unattractive and make the place look cheap. Like having a PTAC. Whether attitudes are enlightened or unenlightened doesn't matter. For the purposes of resale value alone, I wouldn't want to have the only house in town with unconventional equipment.

Efficient and unconventional-looking sometimes go together in marketing. There is no reason that some of the unconventional-looking earlyish (but modern) gas-electric hybrid cars could not have looked like any other car. A large potential market preferred that their cars look as unconventional as their underlying technology. Second generation models looked less like conventional vehicles to set them apart.

Ionized- gw

I think I have it fixed. I installed the mk1 thermostat today. It's Very easy to install. It ran without turning off until I turned it down a degree and the compressor sounded like it was at minimum speed. My problem was what I thought, the intake temperature is not consistent and varied to much. The thermostat is just like any furnace and doesn't have that temperature variance. I don't know who thought it be a good design for the original thermostat in the unit near the ceiling.

I understand. Where I have a ceiling fan, they work better for me in heating mode.

Ask a realtor away from the Sierra foothills, one working in middle class burbs. Yeah, I know here in California that means for houses almost nothing in the market until you get to the beginning 7 figures.

"Smart" in Silicon Valley among the white collar middle class of normal means means trendy visible. PV solar, German cars or in the other direction Tesla or Prius. Minisplits - nope.

Snidely, today, perhaps you are correct, for your area. The issue is the inertia of the market. Most contractors and the structure of the American market support ductwork. For the last 15 years the fastest growing segment of the HVAC industry has been mini-split heat pumps. They are being awarded generous rebates from utilities as the electric industry regains heating market share against gas. You may prefer your ducted systems. Personally, I've had such good results in economy and comfort with mini-splits that after over 50 years in the business I will never install another piece of ductwork.

The rebates and conservation programs are almost always mandated by the governing public utility oversight boards, not originated by the power companies. The power companies would prefer everyone heat with electric resistance heat and use incandescent bulbs, the more the better. Nothing wrong with that, it's their business to sell power.

However with cheap gas nationwide (other than in PG&E territory) and electricity prices that will only rise steeply (as coal and nukes are phased out and costs from building new renewable sources come in ), gas remains the best choice and the cheapest way to heat homes. In any area where natural gas is available, the cost comparison is a no-brainer.

In the mild winters areas of most of the West, heating using hot water, in whatever form, is rare and hard to add as a retrofit. It has never caught on. What remains is ducted forced-air gas furnaces. The ducts then serve for air conditioning.

The term inertia refers to the tendency of a something's state to continue unchanged, whether that's the state of motion or the state of rest. Around here, the minisplit business has no perceivable movement and I don't see that changing.

Thanks to your help guys, I've decided to install the mini split :-)

I'm thinking four indoor units - one for basement (it has an open plan), one for main floor (also has an open plan), two for bedrooms on 2nd floor.

Is it better to have two dual-zone outdoor units or one quadruple-zone unit?

I'm in Washington DC and will use it mainly for heating (~750 sq ft per floor). I looked up winter temps for last few years - it stays above 30 degree, with a few 25 degree days. On those days, I don't mind supplementing with furnace+radiators or space heaters.

Mitsubishi and fugitsu do make muti head units that work in the extreme cold. Theres also units that will work to around 0 which prob work for you also. Still cheaper then resistace heat.

HNY everyone! Quick update - here in DC, we had a warm December but January has started off cold (temperature was in the teens last night).

Air sealing and insulating seems to have reduced our heat loss dramatically! $35 space heaters from Costco continue to heat our home very well. We have 750 sqft on each floor, and one space heater per floor has been sufficient.

I have ordered a mini-spilt and am excited to see how it compares with space heaters. Stay tuned!

Having made these changes, I suggest - put your money into air sealing and insulating, not into HVAC systems. I have come to know everyday folks who heat / cool their 6,000 sqft homes with 0.75 BTU systems for less than $400 per year. It is all about minimizing heat loss/gain (+ properly ventilation).

With a highly efficient building envelope, insulation and air sealing, there is very little payback in highly efficient HVAC equipment. Run the numbers.

You are so correct! My math showed very little ROI, so I ordered a single zone, 1 ton mini-split for $1,000 + installation. If nothing else, it'll add cooling to parts of the house where wasn't cooling before.

I bought an IR thermometer to uncover where we're losing most heat. The walls in our 1937 brick house appear to be coldest of all the surfaces. I have read that adding insulation to walls is ineffective and may even be detrimental (due to fast settling and condensation).

Any other suggestions to reduce this heat loss?

Thanks, as always!

Adding better cooling? The ROI for comfort is infinite for some people and not much so for others :-) I am somewhere in between.

I'm with you on that ionized_gw..