I have tried without complete success to play with duty cycle on my small auxiliary (850W) heater to make it quieter. It has a bad habit of rattling at start up. I didn't want to generate RF with a light dimmer type control so I decided to only switch the heater on/off at zero crossings. To prevent generating a DC component, from being on an odd number of half cycles, I kept the duty cycle time base an odd number of half-cycles so any DC term alternates every other timebase period so nets out to 0V DC. I found that using 5 half-cycle time base was audible, so settled on 3 half cycle time base. This gives me a 1/3, 2/3, 3/3 power options, and the heater was quieter at lower power, but still not dead silent.
My next experiment was to try a newer, more modern cheap aux heater, since mine was probably 40 YO. The cheapest walmart aux heater was significantly more power whihc was not a bad thing, but used a fan, (not great). It was nice to have the extra heat, but the fan noise was undesirable, so I experimented with dropping the voltage to the fan to slow it down. Long story short after attempts to make it work without a fan that failed spectacularly, I never got as quiet as the old school simple resistance heater.
Finally I upped my game to buy a modern baseboard heater. Most of these are 240V but I found one 120V model from Lowes. It's 1kW and runs dead silent. There was some new heater (paint?) smell the first few days but now I have silent running.
I figure the 1kW is capable of heating the room into the high 60's with outdoor temps down into the low 30's, with '20s like we had a couple weeks ago the room temp dipped a little, but that's ok in the middle of the night while I'm under the covers. If we have a really cold spell I can turn on the old in wall heater at a low level to help make up the difference. part deux
I decided to upgrade my storm windows. House was cheap construction using single pan glass windows and permanent outside screens. For a few years now I have relied on "red neck" storm windows, basically drop cloth plastic stapled to the inside of window frames. This helped quite a bit reducing the cold breeze in winter months, and keeping summer heat out, but the reduced visibility sucked. I decided to upgrade to "beverly hillbilly storm windows" . Basically I sourced some clear window film (glorified saran wrap), that I used to cover both sides of some 1"x2" wood frames that I built to nest snugly inside the window sills. Now instead of single pane glass, I have 3 air tight barriers capturing two air pockets for insulation, and I can actually see outside again. I only built these for windows I actually wanted to see out of, in rooms I actually use . I made one for the big 4'x8' picture window in my main room, that I previously left uncovered and single pane. So this should reduce some heat loss there.
I just finished these last week so I need to wait for the next cold snap to see how much better they keep the heat in than my previous approach, but the extra sun light is nice. For my window with air conditioner I made a two part frame. A clear top part that stays in year round, and a bottom part that I can remove in the summer for running the air conditioner. Last summer this air conditioner stayed covered up, and now my house is even tighter so I am making progress.
It's hard to see new progress on my electric bill, since the power company geniuses decided to build a new coal power plant for my region... Massive cost over runs and still not making electricity yet, but they got a rate increase of 15% to pay for part of their pink (gray) elephant. We will pay for the rest of it later.
Now I need it to get cold outside again so I can see how much better my 1000W vs, old 850W and new improved storm windows do.
JR
