I am in Washington State north of Seattle. Summers are moderate and get up to 90 degrees for a few weeks. Winters tend to stay above 35 but can get down to the mid 20s.
Our goal is to have central AC and eliminate our window / floor standing units. I have 11 quotes from 4 companies for a range of options.
The difficult part is calculating the ROI of a heat pump vs furnace. Some companies have told me it will be cheaper and some have told me it will be way more expensive. Not sure what to believe there, so I started digging. The math seems a little complex but here's what I know:
Our highest natural gas bill this year was $0.85 deliver charge plus $0.43 gas cost for 147 therms (pic attached). Our electricity is priced at $0.10 per kWH.
Anyone know how I can calculate this? Our install options range from just an AC and existing furnace for $13k, to full heat pump system and air handler for $19k, to adding heat pump and new furnace for $25k.
Our furnace is 22 years old so we'd like to replace it in this installation to just get ahead of future mishaps.