> Another factor is that AC is the bigger concern for energy usage because AC is used much more of the year. So when replacing your system, whatever money you c

> Another factor is that AC is the bigger concern for energy usage because AC is used much more of the year. So when replacing your system, whatever money you can spend on an upgrade, you're probably better off putting it toward improving AC efficiency rather than heat efficiency. Given that an AC is just heat pump, but with the hot bit outside, and the only thing needed to swap the hot and cold bits is a reversing valve. A high efficiency heat pump is also a high efficiency AC (that’s a very tautological statement). So investing in improved heat pump for heating, naturally means investing in an improved heat pump for cooling.