In the fall of 2006 my wife and I decided it was time to centrally air condition our 1875 vintage home. The hardened wood, cross members and plaster walls do not lend themselves to the use of duct work air distribution whether the duct work is large or small to distribute the comforting and sometimes health preserving cool air. Our first thought was to follow the advice of so many and call in experts in the air conditioning business for estimates and be ready for the next years heat during the winter months. The prices were well above our expectations for our 2400 square foot 2 story home. $13,300 for a 13 seer Puron Bryant system and $18,500 for the Spacepak mini duct system. We got another estimate for ductless units that came in at $12,500. None of these estimates included my 400 square foot work shop about 50 feet from the house and has a block exterior. Looking at the pros and cons of the various systems the ductless approach made the most sense to us, but we had to beat the price offered to us.
Our search began. Ignoring the nay Sayers about being able to figure out how to plan a good, efficient system ourselves we started to Google “do it yourself air conditioning “and wholesale air conditioning. We began to find several sites that would allow us to plug in our dimensions and return the amount air conditioning needed for each room. We began to learn about the seer rating and efficiency. A little common sense thrown into the mix and we came up with a layout and unit sizes (remember we are talking about ductless mini-split AC units) for each room. In our case we actually used two units in our great room to keep our units 12,000 BTU’s or less and effect a circular air flow on our first floor.
We learned later that an independent AC designer would have cost $200-$400 and may not have come up with as good a design because they almost never use more than one unit in a room. In our case it contributed to saving thousands of dollars and creating an extremely efficient layout. This same charge while it is included in the estimate of AC dealers is part of your cost when hiring someone else to do your job.
The reason for adding an extra 12,000 BTU unit instead of going to the suggested 18,000 BTU unit in our great room boiled down to the lower BTU units could be bought as 110-120 volt which are less expensive and cost less to install. It also gave a volume discount from the supplier we decided to use. EXPAIR in New York was advertising a fall sale on Soleus and Hitachi units under 18,000 BTU’s. We bought 4 -12,000 and 4 – 9,000 BTU units for $4800. By the way this included a unit for my work shop not in the other options.
While learning about design we also found out about all the extras that would be needed to complete our job. The items would include two sizes of copper tubing (expensive that year), two sizes of wire, disconnect boxes, tubing insulation, duct tape, plastic down spouts, 3″ key hole drill bits, caulking and circuit breakers. All our supplies came to just under $500.
The units came with installation instructions which made the set up and physical installation easily within a layman’s capability. Locating the outside units as close as possible to the inside unit on the other side of the wall saved on the amount of costly tubing and wire. It also added to the efficiency of the cooling ability of each unit. After running the tubing and wire in accordance with instruction it was time to hook the units up. I made arrangements with an electrician to connect the wires and install the breakers (I don’t mess with breaker boxes) in the circuit box for $200 and I connected the wire to the units, a duck soup job. Arrangements were made with a heating & AC repairman to connect the coolant tubing and purge the system. This is the only reason for having an expert on the job and it cost us $300. The rest of the job was wrapping the tubing and wire with insulation and duct tape then enclosing them in down spouting to protect them from the sun. Job was completed for a grand total $5941.27 and included a 400 square foot workshop.