Licence to Kill
Does it cost more to heat/cool a house that is minimally furnished (one bedroom is completely empty) vs one that is furnished at a more "normal" level?
The Reflectix sounds fantastic! Thank you for the pictures! That helps to understand how you're using it!I made my shade cloths.
Closing too many vents can mess up a system. I don't know the specifics of that but it does impact efficiency if they're the wrong ones or too many of them. It's been trial and error with us.
Some people like to let the temp of their house drop overnight and then heat it up again in the morning. We tried that with the result our furnace would have to run non-stop for several hours every morning and sometimes shut itself down before the house was up to the right temp due to overheating. We concluded we weren't saving any money overworking the furnace on a daily basis. It's much easier to maintain heat than keep changing it.
I don't know if it would make much difference to have more stuff in rooms or not. I think adding insulation to windows in unused rooms, in the form of shades or even rigid foam insulation panels cut to size, would help more.
There's a product called Reflectix that works great to keep heat down. It's bubble wrap sandwiched between two sheets of shiny Mylar. We use a chunk of it in our bathroom window, where the east sun pours in and turns the whole room into a heat sink in the summer. We also use big chunks of it in the two bubbles on the roof of our camper, which also act like solar collectors making it harder to cool the inside of the camper.
You can imagine how much heat two bubbles that size can let in on a sunny site on a summer day. Here's a shot of one of the Reflectix pieces installed in the rear bubble.
It's stiff but flexible and can be cut with regular scissors, so it's easy to work with. The piece in the bathroom window just sits on the sill and gets tucked into the track at the top of the sliding window, so it doesn't require any installation or hardware. When I installed it in the bubbles, I just sized it so it curves to fit the bubbles and it's self-supporting and requires nothing to make it stay in place. It just pulls out when we don't want it in there, and I often open up a corner just by pulling it down so I can look at the sky. It's stiff enough the rest of the piece holds the whole thing in place even with part of it opened up. We also have blinds on the bubbles, but the Reflectix is what actually keeps the camper cool. Reflectix is sold at home improvement stores and is manufactured to insulate around HVAC ductwork to help reduce loss of heat or cool air.