What do MELs, VRFs, and PCMs have in common? Not much and quite a lot—though mostly they’re all topics that energy-efficiency aficionados spend lots of time thinking and talking about. So much information is available at the 2012 ACEEE Summer Study on Energy Efficiency in Buildings that I thought I’d share a quick “brain dump” of key takeaways from some of the sessions I’ve been attending.

In How Much Energy Do MELs Really Consume? Why This Answer Is So Hard to Get: Results from Metering a Sample of Buildings by Jim Dirks of the Pacific Northwest National Laboratory (PNNL), I learned:

• As building HVAC and envelope efficiency continues to improve, miscellaneous electric loads (MELs) begin to represent a larger and growing segment of both commercial and residential energy demand.
• The current magnitude of MELs is not empirically known. The U.S. Energy Information Administration’s Annual Energy Outlook 2012 estimates that MELs represent 50 percent of commercial-sector primary energy consumption.
• PNNL’s proof-of-concept study for metering, monitoring, and analyzing commercial MELs revealed that significant MEL types need to be identified and measured; measurement costs need to be reduced so loads can be measured cost-effectively; and individual MELs should be measured in field applications in sufficient numbers to characterize their consumption patterns and diversity.

In Variable Refrigerant Flow–Heat Recovery Performance Characterization by Harshal Upadhye of the Electric Power Research Institute (EPRI), I learned:

• Variable refrigerant flow (VRF) systems, popular in Europe and Japan for their efficiency, are beginning to be installed in the U.S. HVAC market. There’s little to no actual operational data showing the performance of heat-recovery VRF systems under varying conditions in the United States. EPRI tested a VRF system in the lab to begin to identify operational and performance characteristics.
• The big news here is that EPRI has begun the research that’s needed to identify indicative performance characteristics to provide inputs for VRF system models in building energy software products. Once VRFs can be accurately modeled, U.S. market penetration should take off.

In Phase Change Materials: Are They Part of Our Energy Efficient Future? by Brian James of Southern California Edison (SCE), I learned:

• SCE is testing phase-change materials (PCMs) for building applications—how cool is that?!
• PCM research has been happening for at least 20 years now, but it’s been difficult to get manufacturers on board because of economic concerns. They wonder, “If we build it, will they buy it?”
• One goal of SCE’s project was to begin to characterize the market by determining PCM efficacy in peak demand reduction and energy savings. The project tested micro-encapsulated PCM wall board, floor tiles, and ceiling panels; interior wall insulation; attic insulation between ceiling joists; and drop-ceiling plenum insulation.
• SCE’s research determined that there’s potential for PCMs to reduce building cooling loads, but quantifying the amount of savings will take additional testing.
• Parametric studies of various combinations of climate, building type, PCM product type, PCM quantity (latent heat storage capacity), and HVAC system will have to be performed before consumers can easily identify the optimal PCM application and before utilities can offer incentives for both energy savings and demand reduction.

There’s been so much information to process this week! For my other session recaps, you can read my blog posts Toto, We’re Not in Colorado Anymore and Here with My Tribe.

Were you at the ACEEE Summer Study this year? I’d like to learn what most interested you. If you weren’t there, were you following the conference on Twitter? I noticed a lot of activity with #SummerStudy.