Replacing a 25 year old York split system. Looking at two heat pump option to replace (York & Trane) One dealer ran their heat load program and said we needed a 3 1/2 ton unit (the Trane). The other deal sized it based on the existing unit to be replaced and square footage of house (about 2250) and said it should be 4 tons (the York). The cost difference is minimal so I'm fine paying for either size. My natural reaction is to get the larger (rather have more capacity than necessary rather than less) but I've been told that getting a system bigger than you need is not good. Will the difference of a half ton make that much difference either way?

Also, any issues with the spine fin coil (aka bottle brush) in the Trane unit vs the standard radiator type coil? Didn't know if there were any issues with cleaning the unit. You couldn't comb it out if damaged like you could a traditional kind but didn't know if that was a big issue or if cleaning was a problem.

Over cooling (yes) can cause a problem,, 1/2ton probably wouldn`t hurt you any ,but, you won`t gain anything from it either except to get rid of your money,, there might not be a lot of difference in the unit cost but when you add the cost of a bigger evap coil plus the cost of a bigger line set,, the cost could rise a few hundred bucks. The newer equipment is much more efficient,, you might could get by with a 1/2 ton smaller and get the same job done,, spend that extra money you are willing to give away on a even higher efficient system or spent it on better insulating your house