Portable Heat Pump

I was wondering what can a small household do to reduce carbon emission.  We already minimize power use.  Replacing a boiler with a heat pump has a very long pay pack for a small home, and the neighbours may not like the compressor noises.  Then it dawned on me, portable heat pump!  Especially if you have a single floor, where can you just push it around to the room needing to be heated.   I did some rough calculation, it will saves about 40% of your heating needs, but then if our baseline is low, it still has a very long pay back.