Originally Posted by
Chris Friesen
Why go bigger than necessary? Bigger wire is heavier, stiffer, and more expensive. There are already safety factors built into the code.
Planning for future expansion is different...that can make sense if you're pretty confident that you'll need more capacity in the not-too-distant future.
Just curious, what's the heating portion of that unit rated at? If it's 30A or less then I'd say you're fine, though to be safe you might want to physically disable the cooling portion so you can't turn it on accidently.