A few questions (Trane and air filters)

[BradDS]

We'll be getting a new heatpump system soon and have a few questions. We are going to be moving up from a 2 ton to a 2.5 ton unit. The contractor wants to install a 4 inch thick filter rather than expanding the input for the system. Is this sufficient? We have ample space in the wall to be able to cut 5 inches to make the filter size = 25x20. I'd assume that the larger tonnage installed, the wider the filter needs to be, not thicker. We have a dog and cat and hair often reaches the filter that is currently installed so I am skeptical that the 4 inch filter will last for 12 months as advertised when purchasing it.

The unit that we are planning to install is the XB14 with the TAM7 air handler (which makes the unit 15 SEERS) as well as the 803 thermostat. Are these fairly good choices? We currently have a decent quote for the area, but the contractor is booked up for the week so we will likely be having it put in sometime next week (even though we are without heat or A/C atm...).

[ammoniadog]

As a general rule, the thicker the filter, the less resistance it will create and the longer it will last. With that being said, your concerns about the duct work being too small for the larger system may be valid, as most duct systems tend to be undersized as they are. Is there a good reason you are upsizing the system capacity? I am sure I won't be the last one here to tell you that oversizing the air conditioning (heat pump) is almost always a bad idea. Oversized systems tend to be noisier, they cycle on and off too much, they aren't as efficient, they won't last as long, and they won't remove humidity as well.

[SBKold]

Also recommend to not upsize. And recommend the media filter upgrade. Yes in most cases a dirty media (4-5") will outperfrom clean 1" pleat.