I'm no expert but the difference in the real world is more than that (though am doubtful about 3x the price) . The delta-T between heating and cooling is signi

I'm no expert but the difference in the real world is more than that (though am doubtful about 3x the price) . The delta-T between heating and cooling is significantly greater in most places so you need a bigger system. You also need things like the ability to de-ice.