Phase Change Materials

Hi Becky and – we’ve used PCM on a several projects at least (the ones I’m aware of: RMI, 2 phases UW Molecular Engineering, Stanford Central Energy Plant). The first two at least were driven by the desire to eliminate mechanical cooling – PCM supplemented the inadequate available concrete mass in both structures (interestingly, I saw a recent research summary that suggested that “PCM” [unspecified type] was a high embodied energy/carbon material – would be interesting to see if this were in fact true, and how it compared to concrete). We’ve used BioPCM, and a competing product (forget name) on the 2nd phase of UW project. We’ve done some POE studies on UW (phase 1, phase 2 will be underway shortly) that show that PCM is “lagging” and damping the temp swings of the assmembly. We’ve used it behind gyp, which seems effective, but better in a 9-wood style slatted ceiling where the PCM blanket can be behind a light fabric and more accessible to the occupants’ radiant view. Ceiling grids seems a VERY easy retrofit, and an A/B scientific study of the effectiveness on cooling and conditioning energy would be really cool. In all cases, this has been used as interior mass, and used for NV. Not sure of the relative viability there in more-humid MN. I have heard of applications of using it like insulation in exterior walls – though I am somewhat skeptical, particularly in extreme climates, as once it has lost its phase change capacity it would be close to useless I would (though again, haven’t studied this). =C Chris Flint Chatto Associate AIA, LEED AP BD+C Principal ZGF ARCHITECTS LLP T 503.863.2324 E chris.chatto@zgf.com 1223 SW Washington Street, Suite 200 Portland, OR 97205 From: Becky Alexander

Becky, We’ve worked with Chris and ZGF on the projects he mentioned below. A few years ago we looked to try it out on a university project in Pittsburgh with his colleagues (not quite Minnesota but close enough for the cooling season…I’m in Wisconsin). Given the program, client preferences, and warm/humid summer climate, we found much less natural ventilation opportunity than we did in Seattle or Stanford. Given this, when we analyzed the nighttime recharge of the PCM, we were going to have to actively (mechanically) cool the spaces 4-6oF below our ideal nighttime reset temp. Though we did find that we could shave peak a bit with the PCM for these office and conference spaces, we weren’t able to reduce load enough to shift to an even lower energy cooling system type, we weren’t able to downsize the chiller plant for this 370,000 GSF research facility, nor were we able to realize appreciable overall demand charge savings. We spent a lot of time with the vendor (BioPCM), their contract modeler, and NREL working on understanding the charge/discharge cycles and how to effectively and credibly model the various product line options. For us, the clear conclusion given cost vs. performance was to not use PCM on the project. I’m sure here in the Midwest there are applications where we could leverage PCM, such as in existing buildings with undersized cooling systems (conference rooms are notorious…and dated K-12 buildings without cooling as well) or on low-energy projects leveraging passive design and/or those benefiting from a time of day shift. There might be more comfort benefit for existing buildings than net energy savings (controls upgrades might need to be a part of the mix to make it successful for energy savings). I’ve not been convinced that widespread adoption across an array of building types makes sense. It would be great to see if there have been advancements in the product offering or if others found more value in applications beyond walls/ceilings. Best, Paul Paul Erickson LEED® AP BD+C Principal AEI | AFFILIATED ENGINEERS, INC. 5802 Research Park Boulevard | Madison, WI 53719 P: 608.236.1112 | C: 303.859.7523 perickson@aeieng.com | www.aeieng.com Follow us: [twitter] [instagram] [linkedin] From: Chris Flin

We have used PCM (Insolcorp Infinite R) on a project here in Omaha - case study is pending, but modeling estimates in E+ anticipated 10% reduction from proposed energy cost. This included PCM in select exterior wall areas and above ceilings in interior zones. Building type is professional training center, which includes a large auditorium space. Will keep in touch on results of the case study and look forward to your findings as well.