To heat and cool a new addition, which was approximately one-third the size of the existing home, using an eight foot by twelve foot mechanical room and an existing attic.
We initially intended to use a conventional forced air heating and cooling system on this job. However, once the rough framers where finished and the architects added an additional one-half to the originally proposed amount of windows, we knew we would have to come up with another method of climate control.
Now that the job was underway we could get exact measurements for our new heat load calculations, along with the amount of space available to hide the mechanicals (ductwork and water pipes).
Once that information was available, we realized our heating and cooling requirements had increased dramatically. Not only did this create an additional equipment size challenge, but the ductwork necessary to handle the new air conditioning was enormous. Plus, there was a limited amount of floor and wall space to place conventional supply and return ductwork.
By this time, we were in the middle of the winter and it was very cold. Due to the limited amount of space we had available to position the mechanicals, and because of the architect's additional windows, we were very concerned about being able to heat the rooms. Therefore, we had to use our imaginations.
To throw in the last curveball, the main part of the new addition was a kitchen with a 12-foot ceiling and a family room with a 16-foot ceiling, both surrounded by windows. Above these rooms we had two bedrooms for the children, each with its own bathroom. We had to heat these off the same system!
We decided that the best way to approach this situation was to address the "whole picture". We knew the homeowners were not only concerned about the heating, but they also wanted to make sure they had sufficient cooling during the summer. We decided to use a Unico high-velocity, air-handler unit, which is one of least intrusive air conditioning units available. It would provide cooling during the summer, and because we installed a hot water coil on its back, it would also provide warmth during the winter. We were now able to heat and cool every room in the new addition without having to make any alterations to the building.
We did, however, still have the additional heat load created by the extra windows in the kitchen and family room to deal with. Seeing as we already had a boiler on the premises for the domestic hot water, and the hot water coil on the Unico system, we decided to add radiant floor warming on the entire first floor. This gave us a beautiful way to cover all the bases and made for a very comfortable new addition.