[mejunkhound]

Nonhog:

#2 is the only one I'd consider (of the 3 you mention) if you are not going to do most of the work yourself. I added a 3T to son's hose and kept his nat gas furnace in place (near you, Kent, WA, so climate the same, his is 5000 sq ft house, the 3T work fine all year)

#1 is stupid, #3 is about getting you to spend the most possible.


How about #4, something you can DIY with minimal effort:

Buy 2 ea 1T or 1.5T inverter driven mini-splits online (19+ seer, about $1100 each including shippipng, saves you $200 sales tax right off) Install these at opposite ends of the house. Recently installed one in son's 800 sq ft office, very quiet, cannot even hear the outside unit running 20 feet away.

As for DIY, buy a good vacuum pump off ebay or similar (about $150 for a good one for your purpose) and a micron gauge - another $80 or so. The mini-splits have pre-formed flare fittings.
Install all the mechanical, torque the fittings to spec using oil on all surfaces (POE oil best, get some on line also, you only need a few ounces at most).
Pull a <500 micron vacuum for a few hours and verify no leaks. Open the outdoor unit valves and you are good to go!

If you decide to DIY the mini-splits, plenty of folks here can guide you thru details of the steps above.

Not an ad (I have no interest in the brand), but the last mini-split I bought on-line was a Klimaire for son's office - I figured I was taking a big chance on getting a piece of chinese junk for the low price I paid, but was VERY surprised at the quality and it has worked well for the 6 mo it has been installed. Was actually amazed at how quiet, esp. for someone used to the 80 dB monsters of yesteryear.

PS: leave your propane in place as a backup. ?? are you an seattle city light power or PSE? Probably PSE and off the nat gas grid if you are on propane now.