I'm in the process of drawing up plans to add a floor to my home - roughly 1000sq ft. I currently have about 2300 sq ft, so it is a sizeable increase. One of my key concerns is the HVAC. I currently have a 4 ton HP with an oil furnace (both came with the house when purchased), but my gut tells me that there is something that is improperly designed/sized with the system. Given that I am adding nearly 50% extra living space to the home, I can only assume that I will need to revamp the system. I have looked at the Zuba systems, but I believe that they are only 3.5 ton units. I have also discovered that Carrier has new systems which are comparable to the Zuba.
My big concern is finding a quality HVAC contractor. I've spoken to a couple (including the one that installed the current HP) and they indicated that they calculate the size of the system by measuring square footage and window sizes. That just seems wrong. My gut tells me that there should be a lot more involved in calculating load capacity, including but not limited to, air leaks, etc. In addition to taking home orientation, room sizes, window sizing, E-rating of the windows into account, I would expect a good contractor to need to do a leakage test, air flow test, determine size & location of supply/return vents/etc. How else does one figure out how to best upgrade/retrofit a new system for the home. Am I over analyzing things or expecting too much from a contractor?
I've asked friends and neighbours for recommendations, but no one I know has had this need before, or if they had, simply went with the "rule-of-thumb" calculations (ie: xx tons/sq ft) that their contractor told them.
Does anyone have any recommendations for good, reliable, reputable HVAC contractors in the Montreal, Quebec area who are not just in it to make a buck and blow smoke?