I have an inline duct booster fan with a control. I would recommend just putting one in your existing HVAC duct that runs upstairs. Also, if you don’t already, use your HVAC fan on “On” rather than “Auto” whenever there is an unwanted temperature differential. Overall I don’t think your idea about repurposing the chimney with additional duct work to move air is a bad idea. Especially given your description that multiple renovations have been done and perhaps a holistic approach to the HVAC system wasn’t taken. Our HVAC contractor re-routed our gas furnace’s exhaust gasses that had been going from the basement all the way through all the floors to the attack, the newer model just goes out the wall in the basement. The old exhaust was used to add a return from the upper floor to the basement. And of course, always check that you have more than enough insulation.

A better solution in this case would be a split unit to move the heat out of the home envelope completely.

We added a return to our upstairs and added an in line booster fan to our HVAC system to move more air up stairs. This helped a lot, but I have to agree that first I would look into insulation as it is a cheaper solution and closing a few downstairs vents as needed.

I initially had the opposite problem where my uninsulated cinder block basement was too hot in the summer and too cold in the winter and my basement didn’t have any HVAC registers or returns. The only air conditioning it got was from a window AC unit and leakage from the HVAC ducts. Over several years I ended up adding 2" foam insulation internally to all the exterior walls, insulating the ceiling to the basement (mostly for sound absorption but it also helped with floor temperatures), and adding returns and registers in the basement. I also added an inline booster fan to help pull air up to a second floor bonus room that was an addition. Now the basement is always comfortable, the second floor is much more comfortable, and the energy costs are about the same. My moisture levels are 30-50% in the summer.

I did a radiant barrier on my rafters to guide heat up from the soffits to the ridge vent and then insulated the joists. Blown in insulation is pretty cheap. While doing other work I also insulated my southern facing garage wall and of course insulated the garage door (and sealed the edges). This made a noticeable difference in the temperature of the garage. I can turn a couple of fans on in the garage and leave the door to the house open and achieve a very reasonable temperature in the garage if I plan on being in there for a length of time. This helps in both summer and winter.

I run just one Windows machine with some VMs for various services if needed. Less to maintain and have to tinker with.

I installed cable in a couple of apartments I rented. I just made it look professional and nothing was ever said about it. In one apartment town home I even had access to the attic and was able to run cable in the walls. I did have to drill through the floor and door headers in some instances, but it can be done.

I still use Dia Diagram Editor for most things. I just wish it was still being updated.

Crazy idea, but if you can’t get the bandwidth to support a media server like Jellyfin or Emby where you live, what about placing a server at a trusted relatives or friends house that does have access to high bandwidth? You might need/want to help offset a better internet plan for them though. You could then setup a VPN connection to be able to manage the server remotely and sync files and media to it. You could even use it for off site backup.

I back up everything. I use Stablebit Drivepool with duplication for all of my source code, media, photos, documents, music, books, laptop backups, etc. I back that up periodically to a Drobo DAS and 8 Bay USB enclosure setup under Drivepool. I also have off site backup (working on a new NAS which will be accessed over a VPN). I don’t want to spend the time worrying about loosing anything I have put time and effort into. Been there and done that. Drives are relatively inexpensive but can fail without warning.

After looking at other’s lists I think I am missing a good document server. Emby isn’t the best music and photo server so I could look at improving that, but it has been good enough for those purposes that I haven’t felt like going to the trouble of installing anything else.

• Aster: Multiseat software for Windows allows several users to work on the same PC.
• LaunchBox: Frontend for DOSBox, modern PC games and emulated console platforms.
• Blue Iris: Video security and webcam software
• Calibre: E-Book management and server
• Emby: Server for videos, music, audio books, and photos.
• Firewalla: VPN server, internet monitor and control
• Foundary Virtual Tabletop: Online role-playing game server.
• Grafana: Dashboard interface
• Hubitat: Home automation
• Hyper-V Manager: Tool that allows users to manage Hyper-V hosts and virtual machines (VMs)
• InfluxDB: Real-time database server.
• IotaWatt: Open WiFi electric power monitor
• Microsoft SQL Server: Database Server
• Octoprint: Web interface for 3D printers.
• PCem: Emulator for various old 8086 through Pentium PCs.
• SmartSync Pro: File sync program
• SnapRaid: Backup program for disk arrays.
• Stablebit DrivePool/Scanner: Disk pooling, file duplication, protection, disk surface scanner, and disk health monitoring
• Steam Link: Access and play steam games remotely

Similar situation. I realized my desktop that I constantly upgrade every few years was always going to be faster and more powerful than older or salvaged hardware. I now just keep it on all the time and run VMs on it as needed. Just one physical machine to maintain now! I run Aster on it so it acts as three physical machines. It is my gaming machine, my parteners gaming machine, file server, development server, database server, emulator pedestal, Emby server, Blue Iris server, and my work computer.