I am currently upgrading my furnace from an oil furnace/AC combination to all heat pump. I am considering two stage vs single stage heat pumps.
I understand that two-stage will supposedly give me more 'comfort' (for running on low stage instead of one shorter single stage). However, one of the HVAC company representatives that came out to give me an estimate for a heat pump explained that he doesn't think a two stage is worth it for my house. Here is why;
I have a colonial style single family home (2 levels plus a finished basement, built in the 70s). The way the duct system is setup, the main level heats and cools fine, but the upstairs gets significantly less airflow (with bedroom doors open). Even with an oversized unit and blower, the air coming out of the vents is weak compared to the first floor. With the way my ducts are setup currently, he said that the second floor will not cool well in the summer if a two stage is running on the low stage. In essence, in order to get efficient cooling upstairs I'd need to be running at higher speeds. He was the only one that presented this opinion of several other people that came out.
Does this guy have a point, or will a two stage still give me better 'comfort' even with really low air flow on the second level?
The home is approximately 1600 square feet above ground, and then another 800 square feet for the finished basement. There is currently a 3.5 ton unit a several companies recommended a 3 ton unit.
Note: I am not asking for the ideal solution to my heating/cooling problems. I am asking of single stage and dual stage, which would do better cooling and heating the entire house more evenly in my situation.