We have an ancient ducted system in our 1900 Victorian. The ductwork in the basement is the HVAC equivalent of the Winchester Mansion. The ducts are old, leaky, covered with asbestos, and seem to wander aimlessly often ending at nowhere. We have chosen to live with the $500/month heating and cooling bills (when the upstairs was an inferno in summer and an icebox in winter) because fixing it while it still had life, seemed daunting. Well, it finally died. And it seems a bit foolish to get a new system and just live with the crappy ducts. Also, the hodgepodge of ducts has chewed up an enormous amount of basement space. So, I started thinking about ductless (again)--but in the past I had encountered many contractors who warned me off with horror stories of drops in resale value, general climate discomfort, higher costs of installation and operation...and the unsightly lines climbing up the exterior walls to the second floor and attic. I am feeling suspicious of these warnings though, as Many of those I spoke with, don't install ductless HVAC. So, here are the Details: 1900 three story Victorian Located in Northern Kansas Typical heat Above 90 and 100 degrees for at least 3 months Typical winter temps Vary--but single digits off and on for 3 months is common. The first floor ~1000 sq. Feet, 10 foot ceilings, is quite open with the east and south covered mostly in 24x48 inch windows. But only one window gets sunny. The second floor ~1000sq. Feet , 8 feet, is a maze of closed off rooms. The attic~700 sq. Feet, with ceilings rising 15 feet in several spots, is open and unfinished (future master) The basement is ~1000 sq. Feet. 8 foot ceilings. Unfinished--but on the docket for renovation, as in Kansas it's not uncommon to live down there during storm season. So, questions: 1. Do you have experience with threading the lines through interior walls? Good experience? Bad experience? 2. In a 3 story house with large windows and poor insulation, are we better off just choking down the $25,000-35,000 price tag of new ductwork for central air--and just live with the loss of precious square footage? Or could we just get a more powerful ductless system? 3. Insulation is an issue--something we are trying to work on without wrecking the original plaster and siding. So, with the old walls we will be working within--are there thing we need to look out for? I'm a total novice--so please don't worry about talking down to me. 4. How do we know if a contractor is skilled enough to manage the job. We live in a very rural area--and this is UNHEARD of out here. 5. Right now our attic and basement are unfinished. But once we pay down our loan--5 years--they are up next for renovation. Should we pull the trigger and install lines for all levels now? Take adavantage of some unfinished walls in the main floors of the house? Or is that something that could wait until we finish those areas. Anything else that folks might find pertinent--don't hesitate to educate. If I didn't ask, it's not from lack of curiosity--it's because I don't know what I don't know. Thanks!!

Sounds like a big project! The first thing would be to get a handle on how much capacity is needed in the various living areas. There are various on-line programs that can be used. I did my own using HVACCalc, about $50, and the results were spot-on. Once you find out how much you need, you'll have to figure out what kind of air handlers (heads) you want or need. We used the standard hang-on-the-wall type, and they were inexpensive and work well. BUT- they are pretty ugly to put up in an historic house. We have a central closet, and considered dropping the ceiling, and using through-the-wall type heads, but the efficiency took a major hit, and the cost was significantly higher. There are also ceiling heads, if you have the room over head.

As for running lines, they can be run in interior walls. Our main unit is run that way. Bear in mind the in addition to refrigeration lines, you need a drain for each head. In some cases, a condensate pump is used if gravity drain proves problematic. There are limitations for how long the refrigerant lines can be, so you need to keep that in mind, too. There's also the issue of service access, should the head need to be replaced. I have an access panel behind our main unit (in a closet), so I can disconnect and remove the head if needed. If the refrigerant lines got damaged somehow, I'd probably have to rip open the wall, although I might be able to snake it out and snake a new one in.

Our second unit, in the master suite, has the lines running down the outside. Our home is ICF, so I carved a channel in the foam. I have a removable trim board that covers the lines, but isn't too obtrusive. It blends with the other trim on the home.

The way I bought and installed my Mitsubishi units, they were very inexpensive compared to a central system. I did the 'grunt' work on the installation, and have about $4K in two units and installation. They are very quiet, both inside and out, and the efficiency is amazing. The difference may be that we have a very efficient home, so they don't have to work very hard. I have noticed that they are somewhat slow to bring up or bring down the temperature, so we just let them run during heating or cooling season. I've often wondered if they would be able to keep up in a drafty old house without much insulation.

Mini-spilts are becoming pretty popular here in SC. When I first planned my system 5 years ago, they weren't as well known. Old-school HVAC contractors talked them down as they installed high dollar central systems, and wanted as much money for minis, which is ridiculous. I had one contractor tell me how much capacity I needed over the PHONE! He insisted that a house my size needed 2-1/2 tons, minimum. The actual load is 1 ton for heat; 3/4 ton for A/C. His proposed system would have been way oversized, worked poorly, and would have been expensive to run. Make sure your contractor knows what they are talking about.

Posted By jdebree on 21 Jan 2017 06:30 AM
I have noticed that they are somewhat slow to bring up or bring down the temperature, so we just let them run during heating or cooling season.

JD - My Heating contractor told me that the mini splits are designed to run 24/7, at least on low.

$500/Mo in North KS is nuts! That is a house payment for many Kansan's you must be loaded $$$? Why live there? You like giving money to utility companies vs taking vacations? Sell it, build another, better! Turn it into a hotel, rural KS resort? Rental income pays the bills?

Oh, what fun!

Do you know what your current assuming central air SEER 13 1 stage w/a Gas furnace @ 78% AFU? What the BTU/hr capacity ratings are? How many zones? At some point in the past it must have worked fine as far as comfort?

Which way is the front door facing north? Why is only one south/east window getting sun? North like concordia area or east or west of that?

Ducts full of dusty mold, basement damp too?

With a bill that high for 2700 SF in KS I'm guessing no insulation in the walls, ceilings, basement, windows clear air filled double panes, air leakages high above 15ACH50 w/year round 7-days/wk natural ventilation, uninsulated 30% duct leakages, gas std water heater, 100% incandesent lights, inefficient appliances w extra freezer, large plugs loads, gas leaky fireplace....??

Oh & lets not forget the indoor pool, hot tub, gas grill, 5 wet bars......electronic dance music xmas show, whens the rehab party?

Opps, I was off 1000 Sf, your at 3700 Sf now I'm getting a bill ~ 500/mo w/a MJ8 in Concordia heating capacities of 200K BTU/hr, cooling 140K BTU/hr which is probably oversized ~ 20% based on assumptions above . Sound about right?

Heres some hourly graphs, probably more accurate...had to break apart due to 100KB size limit. Blue heating, orange cooling...Look right? Peaks are what you want to use.