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Residential Energy Use with Michael Blasnik: Lower Priorities

On Friday I shared with you some of Michael Blasnik’s advice on the best ways to save energy at home. But a lot of what I found most interesting about the lecture was how much oft-repeated advice is wrong. For instance:

  1. Blocking off registers to unused rooms may actually make your furnace work harder and waste energy.
  2. Cleaning refrigerator coils regularly may not save energy at all. Blasnik said heat exchangers are so big now that it makes little difference.
  3. Running a ceiling fan counterclockwise in the winter to circulate the warm air at ceiling level doesn’t actually translate into energy savings. (Darn—I was really trying to believe that one.)
  4. A house would have to be really drafty for caulking and weatherstripping to translate into much energy savings. Attics and basements make up 50–75% of air leakage: plumbing stacks, walls without top plates, ceiling height changes, chimneys, soffits, knee walls, recessed lights, and foundation walls. Even then leakage only represents 30% of energy use.
  5. Tankless gas water heaters take just 1/3 off  your hot water load and can cost twice as much as regular hot water heaters. Blasnik says the best buy is an indirect-fired unit.
  6. Cool roofs are just silly in cold climates. They may be good for the Earth’s albedo, but not for energy savings. Good insulation works just as well to keep a home cool.
  7. Single pane windows with storm windows perform almost as well as energy star windows, and a layer of plastic can be just as good as a layer of glass.

Michael Blasnik

Lower priorities

  • Use carafe instead of coffeemaker warmer – costs $0 – $5/yr
  • Cook with lids on pots – costs $0 – saves $2–10/yr
  • Turn off heat in unused rooms – costs $0 – saves $0–200/yr?
  • Clean fridge coils – costs $0 – saves $0–10/yr
  • Change furnace filters monthly (vs. once per season) – costs $0 – saves $0–5/yr
  • Unplug cell phone charger – costs $0 – saves <$1/yr
  • Close fridge door quickly – costs $0 – saves <$1/yr
  • Keep fridge full – costs $0 – saves <$1/yr
  • Ceiling fan in winter – costs $0  – saves $0/yr?
  • Close drapes on winter nights – costs $0 – saves $0/yr?
  • Hot water pipe insulation (after first few feet) – costs $20? – saves $1?
  • Replace old furnace w/92% efficiency (avg. use) – costs $3,200 – saves $250–400/yr
  • Replace old dishwasher – costs $400+ – saves $25-40/yr
  • Caulk/weatherstrip windows/doors – costs $50–600 – saves $10–40/yr
  • Seal basement ducts  (unless big holes) – costs $50–600 – saves $0–50/yr
  • Insulate attic (some existing insulation, no seal) (DON’T DO THIS—SEAL BYPASSES!) – costs $700 – saves $30–60/yr
  • Insulate basement ceiling (1000 ft^2) – costs $1,200 – saves $30–100/yr
  • Cool roof – costs $1,000 – saves $10/yr
  • Tune up gas furnace (annual) – costs $150 – saves $0?
  • Tankless gas water heater – costs $2,500 – saves $60–120
  • Replace 15 old windows – costs $10,000? – saves $50–150/yr

Unfortunately, it doesn’t look like Blasnik has a web site where he shares the sources of all these numbers, so before making any serious decisions based on his seminar, I’d do more research. As a professional consultant, maybe he’s not of the information-should-be-free mindset.

Update: HEET now has Blasnik’s PowerPoint presentation posted. If you don’t have PowerPoint, here’s a pdf version.

One year ago: Stress = Waste


Comment from ryan
Time January 26, 2011 at 12:15 am

I’ve been reading up while my condo building tries to figure out what to do about a water heater that’s down (1 of 2, so it’s a problem but not an emergency.) We’ve got a recirculating hot water system – designed so that hot water is always flowing through plumbing so that people at the far reaches of the building still get hot water immediately, rather than turning the faucet on and waiting for the hot to push out all that tepic water that’s been sitting in the pipes cooling..

I intrinsically get a lot of what Blasnik and you are saying. But I was surprised to see insulating heat pipes on his not really worth it list. It certainly feels like this constantly-on, double-piping system is pushing out a lot of heat. I understand that in the winter, we probably regain much of it that’s lost into the basement. But it still seems like constantly heating a long network of metal pipes 24/7/365 has to have consequences. I wonder whether he was saying it didn’t matter much because he’s more familiar with non-recirculating systems.

Hadn’t seen anywhere to ask him directly, so I thought I’d post here. I’ll keep browsing your blog now.

Comment from Brenda Pike
Time January 26, 2011 at 7:52 am

Maybe it’s different for recirculating systems; I’m not sure. He was definitely looking at everything in a savings to expense ratio, so maybe it’s not that it’s not *good* to do it, but more worthwhile to put your money into other things.

Comment from ryan
Time January 26, 2011 at 3:13 pm

Thanks for the replies. I did get in touch with him as you suggested in your PM, and he graciously wrote back. I thought I’d repost here – partly to get this on the blog-record, since there are a lot of sites that have some form of his list of “not-worth-it” projects, and this is an important footnote.

He assures me that recirculating systems are different. Insulating pipes is well worth it for a set-up with a circulator pump keeping the plumbing warm at all times.

This actually strengthens one of his overarching points – that you really have to drill down into the details to figure out how energy-efficiency advice will work in particular situations. “Your mileage may vary.”

Comment from Brenda Pike
Time January 26, 2011 at 3:18 pm

Thanks, Ryan. He didn’t get into a lot of the exceptions in the seminar, so it’s good to know this. And it’s nice to know that he was so responsive!

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