My old house – an energy saving project
I live in a 1940’s Tudor house that sometime in the 1980’s the previous owner converted the attic into a living space. This is where I do most of my sleeping and most of my writing when I’m at home. The upstairs was done, I’m guessing, with the idea it was going to be a sometimes space and not a living one.
TL;DR – heating and cooling project in an old house to save some money / increase comfort.
Due to the plaster walls on the first floor, general construction of the place, and 1940’s heat ducts going from the basement to the second floor (former attic,) it’s been a bitch to heat and cool. My electric bills in the summer have been sad, and the winter gas bills as well.
In 2012 I purchased an under window unit and paid a fellow for install who promptly disappeared with roughly $3000 of mine (he’d worked on several projects for me before, just decided now as his chance to be a turd,) and as far as I can tell joined a white supremacist group. I didn’t pursue too closely as I had a newborn in 2013 and didn’t sleep for a year.
When the pandemic hit in 2020 I was now spending days in the upstairs of my house as opposed to being there to sleep, shower, and head to work. I felt breezes, mapped out where the heat or cold was coming in, I had a functioning office upstairs, Kim had her office downstiars, and decided rather than once again spending $3000 or so to attempt to power through this heating/cooling fiasco I’d see what could be done by insulation, air management, and the like.
I had a lot of time and as I was at home answering the phone calls and emails I generally would be at work doing the same, I got a lot more things accomplished. My first project was to insulate the upstairs drywalled walls. These had been placed in an attic, framed out, and no insulation placed anywhere around them. There was some at the base but that just kept the heat downstairs. Other side of drywall was 130F+ degree roof as long as the sun was shining.
$200-300 in insulation on the walls later I heat mapped around and saw that every slatted door I had in the place (previous owner loved his slatted doors,) lead to a place I didn’t care what the temp was, and didn’t need to be heated or cooled. With the insulation in, my little Midea AC was able to keep up with the upstairs by itself (I had to have two window units upstairs because no air return, and small ducts for the 1940/50’s runs.)
I decided to get some vent air boosters (I don’t really recommend these unless you want to modify them slightly,) to help pull the cold air up from the central unit, and with the replacement or blocking of all the doors I watched my energy usage to cool the place… almost double.
Took a hot second to figure out that I had previously been heating and cooling for an average occupation of 10-12 hours a day and now was there all the freaking time… so yeah, nothing particularly earth shattering there except it had not doubled and I was there significantly more. It was also becoming more comfy upstairs.
So the summer went, now now paying to heat and cool my wife’s closet, the bathroom, or a couple of random crawl spaces in the attic, and overall it was much more pleasant… until it got cold.
It got cold so of course we baked
There’s a hint of snow in the air, I’ve got the temperature set downstairs where my kiddos sleep to about 66 degrees, it’s a little cool downstairs when you’re closer to the walls. Kids snuggled all warm in their beds I went to get some sleep. I didn’t sleep right for about 4 nights before figuring out that it was stupid hot for sleeping upstairs and my Oolers were unable to compensate.
All my insulation work meant all the heat was no longer escaping. Unfortunately even with shutting off the two air ducts that came up to the upstairs, well, heat rises, it was hot. I slept with two windows open the first night just trying to cool my fat ass down.
I didn’t want to throw away all this heat energy, but trying to figure out how to move it back downstairs I kept running into the issue of not being able to run larger duct work to put a return in. Plaster walls are a bitch. I had two ducts, they were tiny, anything else and I was going to have to take out a wall of plaster downstairs.
For reasons I can’t remember at the moment I had a shutoff for one of the lines. I could go into the basement and throw a lever and that pipe would no longer blow. As I recall this was due to not wanting to pay to heat half of the upstairs and the vent not really ever shutting off, but it’s been a while.
I called my AC and duct work guy and asked him what would be involved in getting the hot air from upstairs back downstairs. He said a return and we talked a bit about whether one could be run outside of the house (going through brick was not a path we wanted to do,) or what the size of the return could be (could I have hoses or something,) and finally, which is what we went with, could one of the vent runs to the upstairs be converted into a return.
The answer was yes, a 1940’s heat vent could be used as an air return as long as you could filter it. He didn’t know exactly how that was going to work but by the next day he’d designed a rather neat solution. The vent feed near the blower now connected to both the air-in (return,) and the air-out sides. Two levers on the feeds allow me to turn it into an air return, a regular vent, or just shut it off.
They also allow me, if I make a mistake, to vent the heat/cold right back into the unit.
Let me tell you, I’m amazed at how much the upstairs duct sucks. you put a Kleenex on the former vent and it’s in danger of being pulled through the grate.
While this looks like a large duct, it connects to something 1/2 the size.
Now when the central fan is on, heat gets sucked out of the upstairs and recirculated downstairs.
I used my incredible carpentry skills to turn one small piece of wood I had into a couple of L shapes, and stapled some media filter over them so I could place in the vent hole of the return/vent without risking it falling two stories and sitting in a duct until I pulled it off. Pictured above, the actual vent pipe is less than half the size of the box that’s shown.
And it worked, until it didn’t quite
For a couple of glorious nights the house was perfect. I don’t know how to properly explain how much the living spaces all being about the same temperature meant to me. This is like a 20+ year project at this point which started with some triple pane windows in 1997 and has reached here.
And then it was once again ass hot. Once again the temp was rising, the heat wasn’t on. My nest downstairs registered the temperature was perfect but upstairs was heating up. Since there’s no thermostat upstairs the nest unit doesn’t know when to kick things on like the fan, which would kick in the air return and make upstairs livable without human interaction, so now I have to figure out how to fix that.
Oh yeah, I can set the fan on the central to fix it, but I want to figure out how to get this automated so I don’t go upstairs and wonder what fresh heat situation I’m walking into.
