Air conditioning is like a globally addictive drug: the more we use it, the more we need it. Its voracious energy demands contribute to the climate disruption that is heating up the planet. That’s only one of several reasons NOT to turn down your thermostat, if your house isn’t getting as cool as you would like. Take 5 minutes to read several practical reasons from The Washington Post that hit closer to home — and our pocketbooks — along with other ways to stay as comfortable as possible through the heat.
Archive Of The Category ‘energy performance‘
PLAYING: I love spring — especially this spring, which has finally arrived, seemingly overnight, after a long, wet, cold winter. I was lucky enough to celebrate it this past weekend with my favorite 6-year-old, teaching him to dye eggs.
WORKING: My favorite climate work is developing education and teaching about energy, emissions, and electrification. I have two of those projects coming to fruition this spring.
- The Tri-County Regional Energy Network (3C-REN — a collaboration of California’s San Luis Obispo, Santa Barbara, and Ventura Counties) is offering a certificate series comprising six classes on “High-performance Fundamentals.” My fellow class developers and instructors are high-performance rock stars Peter Yost, Judy Rachel, Dan Perunko, and Gary Klein. The series launched last week with “High Performance Buildings and Careers.” Peter is up next, on April 20, from 1 to 3pm Pacific Time, teaching “Using Building Science to Design and Build High Performance Homes.”The rest of the classes are on May 4, May 18, June 1, and June 15. All are virtual and FREE to residents of the Tri-County region. Please spread the word to folks you know in the area.
For series info and registration, visit 3C-REN.org/events.
- Also on April 20, from 8am to 3pm Pacific Time, I’ve assembled another all-star cast — Ted Tiffany, Jack Rusk, and Vaclav Hasik — to teach an AIA-approved virtual workshop, “The Architect’s Roadmap to Net Zero,” offered by America Training Solutions. This event will satisfy the State of California’s new requirement for architects to complete five units of continuing education on NZE design to qualify for license renewal.Registration is a reasonable $150-200, and here’s a code for a $50 discount: NetZero-50. Sign up HERE.
The American Institute of Architects California Council recently published the Zero Net Energy Primer. I had the privilege of developing the Primer for them under a contract with PG&E. The Primer (if I do say so myself) is a handsome, concise, and accessible guide — a mere 24 pages, including lots of pictures of ZNE homes of all flavors (small, large, single- and multifamily, luxury and affordable). The AIACC’s goal in publishing the document is to ease the task facing California architects with the roll-out of the State’s 2019 energy code (“Title 24”). The new code will go into effect January 1, 2020 and — while it doesn’t quite get us to ZNE — represents a significant advance in residential energy performance, and the first time that homes will be required to install renewable energy systems. (Of course, there will be byes for projects where it’s simply not feasible to install them.) The Primer will, I hope, help architects get a handle on the ZNE requirements ahead of the looming 2020 deadline.
A recent email thread involving a group working on a video about ZNE design prompted me to raise one of my favorite subjects. Say I, “Will you talk about the critical importance of roof design?” Queried Steve Mann in reply, “Do you have something more specific in mind?”
I’m so glad he asked! It gave me an opportunity to vent (pun intended) about this topic, which I find is absent from far too many conversations about ZNE home design. Here’s what rolled off the keyboard.
- You need to know your (approximate) energy loads early on, so that you have an idea how much solar-appropriate roof area you’re going to need. [That requires a calculation — for example, using NREL’s PVWatts.]
- You need to factor in code-required clearances around the solar array, and depending on the size/shape/proportions of the roof plane(s) in question, those margins can eat up a hefty fraction of the total area(s).
- You need to NOT have vent stacks and other obstructions interrupt that oh-so-critical PV roof area.
- All of the above — to those who are realistic and paying attention — dictate the simplest practicable roof form.
- The less attention you pay to the above considerations, the harder you will have to work on the enclosure and other efficiency measures to achieve ZNE — e.g., adding in more and more expensive measures, such as imported windows.
- Conversely, the MORE attention you pay to (simplifying) the roof, the more flexibility you will have with other building features.
- The simpler the roof:
- the more money you’ll have for other features;
- the less it will cost to develop elaborate architectural details to ensure thermal & moisture integrity;
- the easier it will be to air-seal and insulate the whole building;
- the more likely that the air-sealing & insulation will be done well;
- the better the building will perform; and
- the less the risk of later thermal, moisture, condensation, and rot problems.
So a simple roof is an all-around win: save money, improve thermal and moisture performance, get to ZNE more easily.
It’s time that we rekindle a time-tested aesthetic, one that finds beauty in simple, elegant, well-proportioned forms, robust materials, and quality of craft. One of my favorite architects who has complete mastery of this approach is Steve Baczek. Not coincidentally, Steve spent many years working with Joe Lstiburek and Betsy Pettit at Building Science Corporation — he’s also thoroughly conversant with building science. Take a look at Steve’s portfolio for inspiration!
Lots of people complain about energy models — specifically, how they don’t accurately predict how much energy the occupants of a home (or building) will actually use. This complaint misses the point.
The REAL problem with energy models is that there is widespread confusion about what they can/should be expected to do. Predicting actual energy use for one specific household is not on the list of realistic expectations. Approximating the amount of energy a reasonably large aggregation of households might use? Yes, perhaps, in skillful hands.
The main thing that energy models can and should be used for is to compare the relative effects of different variables on a building’s energy performance, holding constant certain assumptions about the occupants’ usage patterns — which, even in the best circumstances, are fundamentally unknown and must be generalized.
It’s important to remember that a home (except in extraordinarily rare instances) outlives any particular set of occupants and behaviors many times over; those are subject to frequent change. Even one set of occupants will change energy-using behaviors after a time — for example, as toddlers outgrow bathtubs and graduate to shower usage … and then avoid bathing at all … and then evolve to multiple changes of clothing and multiple showers a day (think: soccer and muddy shorts and shoes).
Thus it’s a pointless exercise to attempt a precise fit of behavioral assumptions to a specific set of occupants, or think that we can predict their energy use for any but the most fleeting time period. What we should be doing is designing homes to efficiently serve any household that might reasonably be expected to live there over the life span of those homes.
\With that understanding, and the use of standard occupancy assumptions*, we can certainly use models effectively to compare the relative effects of different features on energy use.