The 2012 ACI National Home Performance Conference was held in Baltimore at the end of March, and was yet again another marathon geekfest. With almost twenty concurrent sessions running from 8 a.m. to 5 p.m., followed by more sessions lasting until 8 p.m., it is a feat of endurance to attend this almost week-long event.This year there appeared to be an underground movement (Twitter handle: #ACIafterdark) that threw late-night parties, although I never managed to figure out where they were.Heat-pump water heatersI managed to attend several good sessions this year, providing good data and food for thought. The first panel I attended covered heat-pump water heaters, and what I learned reinforced my position that they aren’t the great hope of energy conservation that many people believe them to be.Presenters shared results from two studies, both showing only very modest energy savings over traditional heaters. As is the case with most things, the total savings depend on many factors including where they are located in the house, use patterns, and the available free air for the heat pump to take heat from. Tests showed most units to be in the range of 10% to 40% more efficient than electric resistant heat.High volume use maxes out the efficient heat pump mode, requiring the use of resistance heat to make up the difference, lowering efficiencies even more. These studies did not address the energy penalty that they may impose in cold climates where they remove heat from the air which offsets some of the total energy savings.John Straube is quotableJohn Straube was, as Allison Bailes put it, “a walking quote machine.”In his presentation on insulating and air sealing roofs and attics, he was, as always funny, entertaining, and informative. One obvious, but often overlooked, point is that air sealing on new homes frequently leaks in short order as new framing lumber shrinks and creates gaps, while air sealing on retrofits lasts much longer since the lumber is more stable. In real terms, a typical 1/16” crack between drywall and top plates adds up to 12 square inches for each 100 feet of wall.My favorite Straube quote of the day: “R-Value is like IQ — when you’re in single digits, you’re kind of an idiot.” In an extended discussion comparing deep-energy retrofits to minor repairs, he referred to the latter as “turd polishing,” pointing out that you can’t always afford the expensive stuff, and if you are “surrounded by turds, it’s nice if they’re shiny.” Can’t wait to see him again.Some geeks are studying marketingThere were almost continuous sessions on marketing, websites, and blogging, and all appeared to be well attended. The geeks have realized that they need to market, and they (we?) were happily taking notes and tweeting away throughout the sessions.Probably my favorite event was an evening session hosted by Chris Dorsi that was delivered entirely in the Pecha Kucha format that restricts each presenter to 20 slides and 20 seconds per slide. I was impressed at the quality of the speakers and their ability to get their information across quickly and concisely.Book raffleOn Wednesday evening, Dow Building Solutions hosted a party for our new book, raffling off several copies to the group. Three different people with Habitat won copies, but my favorite photo of the night was John Krigger, co-author of Residential Energy posing with his associate Darrel Tenter and our book. I returned the favor the next day by posing with his.Overall, the conference was very good, and not noticeably different from previous years. I still contend that there are too many sessions and they go on too long. Maybe they should just give up all pretension and switch to a 24-hour conference. If you want to be in a session at 8 p.m., why not one at 3 a.m.?There are still too many presenters who don’t know how to put together a readable, visually compelling presentation, and too many are simply not good speakers. As with most conferences, I would like to see better vetting of speakers, something that should happen as videos of speakers become more commonplace.Although I returned home thoroughly exhausted from the experience, ACI was well worth the effort and I expect to return again.