I'm planning on having a Unico or Spacepak system installed in our 1968 split level home which currently has hydronic heating. We've had both Uncio and Spacepak contractors quote on the job, but we've gotten different answers from all vendors, who is correct?
Our home is around 3900sq ft. with two levels being above grade, one level partially below grade and the lowest level completely below grade. We live in Michigan, so the summers are not super hot, but we did have many days in the 90's this year. As the two lower levels maintain a lower temperature then the upper two it has been suggested by all contractors that we install a system only on the upper two levels which comprise about 2000-2500sq ft and as cool air descends it will naturally keep the lower levels cool. The home has blown cellulose insulation, 10 ft. ceilings on the upper level, and 15ft ceilings on the living room, dining room and kitchen level. We have large glass exposure on the living room level, but this faces North. Other then this we have typical glass exposure on the South side bedroom levels. We have shade tree coverage on 50% of the roof area by mid spring.
The problems begin when they start recommending systems. Two contractors are suggesting we use a 5 ton condenser with a larger Unico system air handler with around 30 to 31 diffusers. Two others are suggesting we use a 3 1/2 ton compressor with a smaller Unico air handler and around 20 to 21 diffusers. The final one is recommending a 3 1/2 ton unit with only 17 diffusers, and insists that Unico recommends no more then 5 diffusers per ton. However upon calling Unico direct I was told they recommend no less then 6 diffusers per ton, so obviously the latter contractor is no longer being considered.
We prefer it to be a little cooler then most, so we wouldn't mind the extra headroom a 5 ton might provide, but understand that if the condenser is oversized that the unit might not remove as much humidity on cooler days when the system wouldn't be on as much. Would it make any sense to go to a 4 Ton and split the difference? I called Unico direct and talked to a rep, but he said they all could be right (not the answer I was looking for). Not being a HVAC professional, just a confused consumer, I'm lost as to which company is right and which is wrong, any HVAC professionals with an opinion on who is right and who is wrong?
Also one vendor carries and suggested the Spacepak system. From the outside they look the same to me. I have read that Spacepak was the first, and that Unico started from some employee's that left Spacepak when it was sold to another company. Is there anyone who has installed both who has an opinion on durability and quality of Spacepak versus Unico? or consumers who have had either system with good or bad experiences?
Thanks to all who reply.