For calculating historical heat loss that is for you to do. Outside contractors don’t have your historical fuel bills.

Since you have central ducting, system design is easy - any HVAC contractor can install a appropriately sized central heat pump to replace a furnace.

Final note is that the operating cost of a heat pump in Cambridge is currently more expensive than a natural gas furnace.

You don't want an HVAC engineer (people who prototype HVAC equipment to be made in factories), and as you correctly surmised most contractors won't put in much effort on system design either.

Given this is a condo in Cambridge, it likely is a very old building. This means even Manual J calculations by "diligent HVAC contractors" are probably very inaccurate. The best way to size a system would be to use your historical fuel consumption from past years https://www.greenbuildingadvisor.com/article/replacing-a-furnace-or-boiler. This will be the most accurate way to determine your empirical heat loss, which would determine sizing, the most important design factor in a heat pump.

Further details about system design and selecting equipment will depend on your specific needs and considerations.

Do you know how to use “tl;dr”?

Here's the real context. Parking officers don't work at midnight normally, which means someone called the cops on you after hours. The cop would be forced to tow you (at after-hours pricing) and went beyond their minimal obligations to contact you first.

As for whether this is considered harassment - it wouldn't even be considered harassment by a private citizen. Like it or not, this is the United States and the bar for harassment by a police officer is incredibly high. Most people try to be polite and deferential to police officers because they can legally make your life a living hell.

YTA, the police officer was doing you a solid by letting you know instead of straight ticketing and towing at extortion-level pricing ($300+).

You don’t deserve special treatment for being an engineer or paying your taxes. It is somewhat alarming that that this is your first line of thought in terms of context.

The Cambridge parking pass at $25 per year is a massive subsidy to residents and it’s absolutely understandable that they would be strict to verify eligibility.

>since Nissan is Japanese, it is reliable

Nissan build quality went downhill after Renault bought it, and is also associated with scandal-ridden Carlos Ghosn. If you wanted to buy a Japanese car, why not Toyota and Honda? They sell much higher volume overall so parts availability and mechanic familiarity will be much better than Nissan.

Those looking for a reliable car who don't drive much wouldn't want to pay slight premium (for some reason Nissan is marginally more expensive than Toyota/Honda) for Nissan just to differentiate themselves. That decision might pan out different for different demographic groups in different parts of the US.

Gentle reminder that Comcast does not do identity verification for “new subscribers”.