Yvonne Tran, Efficiency & specs editor

My job is the numbers, and mostly the question of where each one comes from. SEER2, EER2 and HSPF2 belong to an exact pairing of indoor and outdoor unit, so I check them against the ENERGY STAR listing and the manufacturer's own sheet instead of trusting the headline on the product page.

Cold weather is where I get stubborn. "Heats in sub-zero weather" means the system still runs at that temperature. It says nothing about how much heat it delivers there. I go looking for the capacity table at low outdoor temperatures, and when a listing doesn't have one, the guide tells you to ask for it before you order.

I also read the parts of the manual people skip: how often the filters want cleaning, what voids the warranty, how long the compressor is covered compared with everything else, and the noise ratings along with the conditions behind them. Owner reviews help here. When several people mention the same rattle or the same iced-up outdoor coil, I note it next to the spec sheet.

I write the guides on efficiency ratings, cold weather, placement and noise, and maintenance, and I edit Melissa's pieces on zones and on mini splits versus central air.