Super interesting product! I've been chewing on this idea and market for a while (as a potential customer, primarily) but with a slight twist. Conventional heat pumps tend to fall back to resistive heating as things get colder; where I'm at in Canada, we routinely hit -40C/F in the winter and unfortunately this means that the efficiency is the worst when we need it the most. Your approach with the improved condenser is great but... any thoughts on how it would handle -40F?