Image Credit: Martin Holladay John Straube at the Building Energy 13 conference in Boston.
Image Credit: Martin Holladay Michael Blasnik at Building Energy 13 in Boston.
Image Credit: Martin Holladay This World-War-Two-era poster was highlighted by Michael Blasnik in his presentation at Building Energy 13. Ken Levenson is a representative for Four Seven Five, a distributor of European membranes and tapes. The photo shows Levenson on the trade show floor at the Better Buildings By Design conference in Burlington, Vermont.
Image Credit: Martin Holladay Carl Seville looking somewhat curmudgeonly at the Greenprints conference.
Image Credit: Martin Holladay Rob Watson, often referred to as the "Father of LEED," spoke at the 2013 Greenprint conference in Atlanta.
Image Credit: Greg Brough, Southface Martin Holladay gave a two-hour presentation at Greenprints. His topic was, "We Can't Build Our Way Out of the Climate Mess."
Image Credit: Karyn Patno Panelists at the closing forum of the NESEA conference in Boston. [Photo credit: Matthew Cavanaugh]
Image Credit: Matthew Cavanaugh Bruce Coldham, acting as master of ceremonies at the "Stump the Energy Nerd" event, made Martin Holladay laugh out loud at the NESEA conference in Boston.
There are lots of reasons to attend conferences. At a good conference, we get a chance to network with colleagues, to learn about recent research, to see new products, and to talk with manufacturers’ reps. I’ve had the good fortune, over the last six weeks, to attend three conferences focusing on green building and residential energy:
- The Better Buildings By Design conference (sponsored by Efficiency Vermont) was held in Burlington, Vermont, on February 6 and 7, 2013.
- The Building Energy 13 conference (sponsored by NESEA) was held in Boston on March 6 and 7, 2013.
- The Greenprints conference (sponsored by Southface Energy Institute) was held in Atlanta on March 13 and 14, 2013.
It would be a daunting task to report on all of the excellent presentations I attended at these three conferences. While I hope to report in depth on some of the presentations in coming months, I’ve decided (as a stopgap measure) to share a collection of pithy quotes gleaned from all three conferences.
Bill Rose is a research architect at the Building Research Council at the University of Illinois, and the author of the landmark textbook, Water in Buildings. At the Boston conference, Rose said, “If you do something to the building envelope to make the exterior colder, it will be wetter. Cold means wet; warm means dry. This pertains to materials outboard of the thermal envelope, primarily during cold weather. At a given vapor pressure, chilled materials are wetter than warmed materials. This is an equilibrium condition. It is not a consequence of diffusion, air leakage, or drying potential to one side or the other.”
Green building programs
Carl Seville, the Green Building Curmudgeon, is a consultant based in Atlanta. At the Greenprints conference, Seville said, “The different green certification programs are essentially similar in concept. LEED has the most onerous documentation requirements. That’s job security for me. The 2012 version of the National Green Building Standard is based on the 2012 energy code, while LEED is still down at the Energy Star Version 2 level. USGBC is like a battleship that can’t turn very easily. Now it is the least difficult program to comply with from an energy standpoint.”
Carl Seville: “On the single-family side, the client usually hires me to pursue a green project, and I have to bring the builder along. Sometimes builders are doing it for a spec house, but usually it is client-driven. About two-thirds of my projects never get certified. They just give up.”
Carl Seville: “Certification is just a label. If you follow the energy code, and the building code, and the manufacturers’ installation instructions, you have essentially done what you need to do. The problem is that those things are never done. That is why green certification make sense — because there isn’t any other mechanism to make sure that the work is done right.”
Rob Watson, currently the CEO of EcoTech International, was on the board of directors of the U.S. Green Building Council for many years, and is known as the “Father of LEED.” At the Greenprints conference, Watson referred obliquely to Henry Gifford’s criticisms of LEED without ever mentioning Gifford’s name. Watson said, “Some early LEED buildings had piss-poor performance on the energy front. That has started improving significantly. … Our job [in developing the LEED program], early on, was to make friends and get the whole idea of green construction established. In hindsight, I think we did a decent job, but there were a couple of things I would have done differently. … USGBC is a voluntary standard-setting organization, not a regulatory body. It is trying to set a standard. I think that you saw from the list of buildings in New York [referring to a slide showing the actual energy use of some New York City buildings], buildings that were listed by address, what their emissions and energy use are. This [type of disclosure] will be growing, but that will be handled by another entity. It’s not USGBC’s job to do that.”
John Rahill is an Vermont architect. At the Burlington conference, Rahill said, “It’s silly to think we can install siding that doesn’t leak.”
Rob Watson: “Art Rosenfeld, the former California Energy Commissioner, told me that green roofs, as it turns out, don’t do anything for the urban heat island problem. The solar energy gets absorbed and transpired. We used to think it was a sensible heat issue, but it turns out that it is a latent heat issue. That’s not to say that green roofs are bad — just that they don’t prevent urban heat islands.”
John Straube is a principal at the Building Science Corporation in Westford, Massachusetts. At the Boston conference, Straube said, “As you increase envelope R-values, you also have to increase your airtightness. And there is a third component in these decisions: the windows. You improve the insulation levels, and then you improve the windows, and then you improve the airtightness. It’s all about figuring out the best combination. It would be stupid to make an R-60 house that had air leakage of 3 ach50.”
John Straube: “What’s the traditional way to build? You install the worst legally allowable level of insulation. Then it is installed badly, so you it performs at less than half its theoretical value.”
John Straube: “Many people say, ‘There are diminishing returns to insulation, so beyond — pick a number — it’s not worth insulating.’ It used to be R-5. According to a certain insulation manufacturer, it’s R-20. The number you pick is open to debate, but everyone agrees that at some point, it gets a little absurd. Every time you add insulation, you save energy. The question is always, ‘Is it worth it?’ It’s tricky, because it’s hard to figure how much it costs, and it’s hard to figure out whether it’s worth it. Most code requirements are on the low side.”
John Straube: “You have to assess the cost of increasing insulation. Adding R-7.5 to the outside of a 2×6 R-15 wall is expensive. But for a production builder, the upcharge to go from R-30 cellulose to R-90 cellulose in a vented attic is shockingly low.”
John Straube: “For a building in Boston with code-minimum insulation, it’s probably better to spend your money on better windows and airtightness than on more insulation.”
John Straube: “As your R-value goes up, if you care about getting to high thermal control, you obviously care about high airtightness. In a superinsulated building, it takes very little air flow to make a bump in heat flow. You won’t get the benefits of deep attic insulation unless you have a super-airtight ceiling.”
John Straube: “The optimal R-value is a holy grail. You can look for it your whole life and never find it.”
John Straube: “We have seen people buy windows from across the ocean, at high cost, for a very small incremental improvement in thermal performance. They should just add another kilowatt of PV, rather than chase after the very small incremental savings from the expensive windows.”
John Straube: “The bigger problem of design is poor heat flow control: thermal bridges, air leakiness, and poor solar control. As we add insulation, we will experience summertime overheating problems. You design the building for winter and sweat all summer. So you need to think about operable shades, low-solar-heat-gain windows, and better AC systems. These other things are a bigger issue than the question of whether R-30 walls are better or worse than R-40 walls. Don’t get dogmatic about rules of thumb like 10-20-40-60. It’s just supposed to get you thinking about what you should be aiming for.”
John Rahill: “Attics are rarely built as drawn. Whether or not they are shown on the plans, you end up with ducts, recessed lights, and storage.”
John Straube also spoke at the Burlington conference, where he said, “For a townhouse, the domestic hot water load is often equal to the space heating load. You can’t ignore domestic hot water anymore.”
John Straube: “Smaller HVAC units are usually more expensive. You end up spending 50% to 200% more to buy a product that is half the size. The Passivhaus people used to say, ‘We will downsize the heating system and save a lot of money and put it toward insulation.’ That may work in Europe, but it doesn’t work here.”
John Straube: “Ductless minisplits are not attractive. It looks like I’ve got a wart on my wall. This is a major challenge when we propose these units to homeowners. They say, ‘Those wall warts don’t fit into the colonial décor.’ ”
John Straube: “What about air-to-water heat pumps like the Daikin Altherma? Well, the prices are in some cases insane — $15,000 to $20,000 for most systems. Given the energy consumption of these low-load houses, it’s hard to justify this kind of investment. It’s the same problem with ground-source heat pumps.”
John Straube: “If you only have to provide 5,000 Btuh, does it matter much what the efficiency of your equipment is?”
John Straube: “Energy Star builders in New York state are building really good houses but getting comfort complaints because their equipment is too big. Once you get a good skin, the mechanicals can only screw you up by making the house energy intensive and hurting comfort.”
Duncan Prahl is a research manager at IBACOS in Pittsburgh. At the Boston conference, Prahl said, “Point-source heating raises interesting questions. The building code says that you have to provide heating in every room. What if you have a ductless minisplit in the living room or the hallway, but not in the bedrooms?”
Duncan Prahl: “Comfort is subjective. Five percent of the population will never be comfortable, no matter what.”
Energy saving tips
Michael Blasnik is an energy consultant in Boston. At the Building Energy 13 conference, Blasnik said, “I got an e-mail from ACEEE. The subject line was something like ‘Ways to save energy this winter,’ or ‘17 ways to green your home.’ Almost everything they said was wrong. Well, let me modify that. Maybe a few of the things they said might be right, but we just don’t have the data to support it. Where are these recommendations coming from? I don’t know. Someone made it up. Most free energy advice is overpriced — they should pay you to listen to them.”
Michael Blasnik: “Here is a poster from World War 2: ‘Winterize your home: insulate your walls and ceilings; install storm sash.’ This is better information than we are getting now.”
Michael Blasnik: “To make energy retrofit decisions, all you need is a basic decision tree. You don’t need computer software. Leave the energy modeling to the people at the national labs.”
Michael Blasnik: “Tankless gas water heaters do save energy — about 65 therms of gas a year. They don’t necessarily work well and they are expensive, but they do save energy. In retrofit jobs, installing a tankless water heater costs about $2,500, because you have to upgrade the gas line, install a flue, and bring electricity to the unit — so it’s often a 30-plus-year payback. And if you need an annual maintenance contract to flush the unit to stop scaling, that wipes out all your savings.”
Michael Blasnik: “A complex HVAC system is just an invitation to disaster.”
Michael Blasnik: “About 7% of all air handlers and furnaces have the blower control set to ‘On.’ You can save 3,000 kWh per year if you flip the blower switch to ‘Auto.’”
Michael Blasnik: “Window replacement has a 100- to 300-year payback.”
Michael Blasnik: “Tuning up a gas heating system results in zero energy savings. Right-sizing heating systems or air conditioners results in zero energy savings.”
Solar thermal systems
Jon Child is a worker-owner at PV Squared, an installer of renewable energy systems in Greenfield, Massachusetts. At the Boston conference, Child said, “We used to be in the solar thermal business. We are now focused on grid-connected PV. Traditionally, domestic hot water was provided by a solar thermal system. We’re not doing much of that anymore. Electric heating technology advancement now provides a highly efficient alternative: heat-pump water heaters.”
Energy retrofit work
John Tooley is a senior building science consultant at Advanced Energy in Raleigh, North Carolina. At the Greenprints conference, Tooley said, “To grow an industry, you can’t depend on ‘best practice.’ Best practice is based on opinions. An opinion is a view or judgment formed about something that is not necessarily based on fact or knowledge. Doing work right requires a plumb line. You need to know if a method is right or wrong. That’s not based on opinions, but on specifications. A specification is an act of describing or identifying something precisely, or of stating a precise requirement.”
Robert Kahabka is a trainer for Northern Comfort Diagnostics. At the Burlington conference, Kahabka said, “Tightening up old buildings that were built to your grandfather’s standards has been an elusive goal. You can work like a dog for two days, check your results, and be disappointed. Sometimes old buildings have secrets they don’t want to give up. Weatherization workers spend way too much time identifying where we need to work.”
Robert Kahabka: “When I go out in the field with contractors, I ask, ‘How do you find air leakage?’ And they usually say, ‘Oh, we have a blower door, and we walk around and we feel with our hands.’ But high-velocity cold air is easier to feel than low-velocity tempered air leaks from a return air grille. This is the 21st century. We have better techniques.”
Robert Kahabka: “In a 6,800 heating degree day climate, we can save the customer who burns fuel oil $570 in energy per year just by air sealing. We’re not even talking about insulation improvements. The average weatherization program air seals at least 60 houses a year. So if you work as an air sealer, and you’ve been in the business for 15 years, and you’ve been reducing reducing air leakage in homes with oil heat by 1500 cfm, then the savings for homeowners over 15 years is $2 million. And if you are doing 110 air sealing jobs a year, after 15 or 20 years of service, it adds up to maybe $7 million of energy savings. So if gold costs $25,600 a pound, then a good air sealer is worth his weight in gold.”
Robert Kahabka: “Infrared is the tool of choice, almost every day of the year. Try to use it more than just as a winter tool. If the attic is 130 degrees, I have great delta-T. The more you use infrared, the better you get.”
Robert Kahabka: “Identify leakage pathways with diagnostic smoke. An infrared camera costs $5,000, but diagnostic smoke is only $35. This is the technique that has helped me in so many situations look like a brilliant scientist: my trusty smoke stick. Once I figured this out, I thought, ‘Why wasn’t I using this tool 10 years ago?’”
Robert Kahabka: “You can made a big difference to the air leakage rate in a building just by insulating it. Pull a second-story floor board or drill a one-inch hole into the ceiling below to access the band joist area for blowing cellulose. Sometimes I have to pull the siding to get to the band-joist areas with cellulose.”
Marc Rosenbaum is the director of engineering at the South Mountain Company on Martha’s Vineyard. At the Burlington conference, Rosenbaum (who was reading a slide prepared by his absent co-presenter, Ben Graham, who was sick on the day of the conference) said, “At some point in that history, things are stable. Then, later, things are in transition. What kind of period of human history are we in? This is a transition period. We are not likely to reach another equilibrium point in our lifetimes.”
Alex Blumberg is a producer for the public radio program “This American Life.” At the Boston conference, Blumberg said, “The world is full of radically different people. There is a way of putting forth a message, of convincing people that what you have to offer is something they want, without using the word ‘sustainable.’ There are a bunch of people out there who don’t give a sh*t. Given the choice, they would definitely kill the polar bears. But there are probably ways to present the issue so that they would prefer a solar solution to a coal solution. A lot of that has to do with price. You have to start thinking, ‘How do I sell my message to the NASCAR fan?’ ”
Martin Holladay’s previous blog: “All About Rainscreens.”