Well superstorm Nuri has made its presence felt across the nation and put a chill on my ambitious exterior project. The early arrival of arctic air is making this November feel like a cold January. The Upper Peninsula and West Michigan have gotten feet of snow. South Buffalo suffered over 5 feet of snow yesterday. It sounds like I had it easy last night when I was fighting a 14 mph wind in 16 degree weather while trying to get some storm windows hung up.
My fiberglass pipe insulation arrived in 6 large boxes as scheduled. I ended up spending somewhere around 3 evenings getting about 190' of insulation onto the horizontal steam pipes in the basement.
You can see I didn't keep a clean workspace. I was hustling to get the fiberglass insulation hung as soon as I could. Time is money folks!
You can read a lot about insulating pipes elsewhere on the internet but I'll share several things I learned during the process:
- When you measure your pipes, be on the lookout for fittings that reduce pipe size. I didn't catch a couple until I measured a second time (thank goodness). You can take the circumference or the diameter of the pipe and convert it to NPS (Nominal Pipe Size) on the vendors' websites. My house has 3" nps mains which reduce to 2.5" after about 25' feet of travel where they split in a T to form 2 loops that return to the boiler. The loops are mostly 2" pipe. Off the main loops, I have about 9' of 1.5" pipe and then a bunch of random 1.25" and 1" pipes before they head vertically into the house.
- The advice online was to buy the thickest insulation you can afford. From what I could tell, 1/2" isn't worth the effort, 1" will get you 86% more efficient, 1.5" will get you to about 90%, and 2" will get you around 92%. Anything over 2" thickness runs into the effect of diminishing returns. I would only get over 2" if you have a huge steam main (over 3" nps). I went with 1.5" thickness for all of my pipes.
- Be prepared for some creative cutting if you have a lot of condensate return pipes or other fixtures in close proximity to the steam pipes. I had several pipes I had to uniquely trim sections to fit around. It provided a nice sense of accomplishment when you measure just right and it fits around the obstacle like a glove!
- Be sure to do your carving where the two halves of the insulation meet. Otherwise you won't be able to get the insulation around the fixture. There is a good YouTube video I have embedded below that shows how to carve around fittings.
- Wear a mask, safety glasses, gloves, and long sleeves. Fiberglass itch is annoying. And I suspect fiberglass itch in your lungs and eyes is more than annoying and maybe even dangerous.
- I used an old serrated kitchen knife to cut the insulation to length. It worked really well.
- Be careful not to get rust or dust on the PVC jacket's adhesive. The jacket won't want to stay closed if you don't.
- I found the best way to tape over the butt joints between insulation sections was to stick as little of the tape onto the top as possible and then with both hands stretch the tape straight down and then keep it somewhat taut as you wrap it around the bottom and back up to the top. I think pros use a squeegee to get a perfect seam but this method got me close enough. And it's pipe insulation. In a basement. Who cares if you look like a "hack" or not?
- Try to avoid compressing the fiberglass. This is why you have to carve out space for fittings. If you compress the fiberglass around them, the insulation value is lost.
- They sell PVC covers for the fittings. I will probably buy some when the budget allows because you can still lose a substantial amount of your hard-earned money to the basement air at the fittings. And they make you look like less of a hack.
- Measure twice and cut once!!!
In other news, it might warm up into the mid-40s this weekend. I could paint but primer is out of the question. My paint says it doubles as a primer. I guess I could see if it matches without primer underneath so that my house doesn't look like a patchwork quilt all winter. It's important to have your colonial look symmetrical and coordinated!
Before any painting occurs though, I'll have to try to get my storm hardware that I removed for painting back up without aid of the scaffolding. Thank goodness I still have the 2 28' ladders on loan from my gracious builder neighbor, Mr. Von Brockdorff! Until then the boiler will be running more than it should be. Storm windows make a huge difference even if they're not airtight.
I also received my first energy bill of the heating season. The good news is that after less than a week of insulation, I've already used less gas than last year at this time despite it being colder overall I believe.
I now have my third energy bill of the heating season. The insulation has definitely helped with my heating efficiency. I haven't yet purchased the pipe fitting covers which I think should help a little bit more. There will be some efficiency left to be gained that I will never achieve because of pipes that go up into the walls without any insulation around them. I didn't think to factor that into my "return on investment" calculations. Here is the latest chart:
After obtaining the number of Heating Degree Days (based on an internal temperature of 65) for each month represented on the graphs, I calculated the average natural gas usage per HDD to factor out the differences in temperature. HDD uses the outside temperature compared to the inside temperature to reflect the demand for energy to heat a structure. The higher the number of Heating Degree Days per month, the more energy required to heat the building to 65 degrees. Then I compared months from last season to this season. The difference is the amount of efficiency I gained from insulating the pipes assuming all else is equal (the hot water heater and some removed storm windows are probably significant variables).
The results so far have been good. For November and January I have increased efficiency by about 24.5%. December was only a 14.3% increase most likely due to effects of working on the exterior of the house. If we remove December as an outlier, about 33 HDDs is balanced by 1 Mcf of gas whereas last season only about 24.5 HDDs was balanced by 1 Mcf of gas. If we use today's gas rate and weather and compare it to the energy needed per HDD, I calculate that I have saved $195.40 so far.