Some thoughts on conducting energy and environmental research during the first 2 months of the Trump administration

I don’t think of Twitter threads as a particularly helpful means of communication, but it’s a good way to rant about my experience conducting energy and environmental research during the first 2 months of the Trump administration:

Thanks to Chuck Haas at Drexel University as well for making a Storify of this thread.

New 3D printer test: Up Box+ Printer with HEPA filter

We recently tested emissions of ultrafine particles (UFPs) and spectated volatile organic compounds (VOCs) from an Up Box+ desktop 3D printer using ABS filament, which is a relatively unique product on the market because it includes a 100% recirculating HEPA filter inside a full enclosure in order to reduce particle emissions. It’s one of the first, if not the first, printer that we’ve seen specifically address UFP emissions. (However, we should also note that it does not have any intentional gas phase filtration to reduce VOC emissions). Results of our tests are provided in detail in the full report, but briefly:

  • The total number of UFPs emitted throughout the test print job was reduced by about 74% simply by printing with the enclosure completely closed (but no filter operating) compared to operating the printer with an open enclosure
  • The total number of UFPs emitted throughout the test print job was reduced by about 91% by printing with the enclosure closed and HEPA filtration system switched on compared to operating the printer with an open enclosure
  • VOC emissions were relatively low compared to other printers and filaments we’ve tested, although surprisingly, operating the printer with the enclosure closed (but without the filter operating) actually increased VOC emission rates by about 50%, while operating the printer with the enclosure closed and with the HEPA filtration system switched on decreased VOC emission rates by about 20%. However, both of these values are near the estimated uncertainty in our measurement and we didn’t get a chance to perform replicate testing, so it’s not clear how meaningful the VOC results really are

New batch of 3D printer filament emissions tests available

We have released 7 new reports on ultrafine particle (UFP) and volatile organic compound (VOC) emissions tests conducted in our lab in 2016 using a Lulzbot Mini 3D printer and 7 different commercially available filaments. Scroll down to the bottom of our 3d printer emissions testing page to see the reports, or download them below:


Comments on new working paper ‘Do Energy Efficiency Investments Deliver? Evidence from the Weatherization Assistance Program’

Economists Meredith Fowlie and Catherine Wolfram at the University of California, Berkeley and Michael Greenstone at the Energy Policy Institute at the University of Chicago (EPIC) have published a new working paper on the economics of residential energy efficiency retrofits, in which they present some discouraging results:

I first read the short research summary from EPIC, “Costs of Residential Energy Efficiency Investments are Twice their Benefits: Implications for Policy,” and found some surprising conclusions that led me to dig deeper into the actual working paper, “Do Energy Efficiency Investments Deliver? Evidence from the Weatherization Assistance Program.”

Continue Reading →

Literature round-up: June 2015

It’s been forever since I’ve done one of these literature round-up posts, but you could say that about a lot of post types on here….

Regardless, here are a few recently published papers that I find really interesting:

  • Ji and Zhao, 2015, PLoS ONE, Estimating Mortality Derived from Indoor Exposure to Particles of Outdoor Origin – this is a really important effort to combine outdoor air pollution data (PM2.5 and PM10) with a mechanistic understanding of how outdoor particles infiltrate into indoor environments (where we spend most of our time) and estimate the impact of indoor exposure to particles of outdoor origin on mortality. Basically: in the US, Europe, and China, our indoor exposures to outdoor PM account for about 80 or 90% of the mortality associated with outdoor PM. This is something I’ve been thinking about and saying for several years now, so I love to see the work that Bin Zhao and his group are doing at Tsinghua University!
  • Bouslimani et al, PNAS, Molecular cartography of the human skin surface in 3D – This one is intense — basically, our bodies are literally covered with both chemicals and microbes, but the chemical makeup of skin surfaces aren’t well understood in total. This paper swabbed the hell out of some peoples’ skin and performed mass spectrometry (for the chemicals) and 16S rRNA sequencing (for the microbes) and made a 3D map of the data. They ended up with some wild human chemical/microbial plots like this:


  • Langevin et al, Building and Environment, Simulating the human-building interaction: Development and validation of an agent-based model of office occupant behaviors – This is very cool work that develops and validates an agent-based model of occupant behavior using data from a long-term field study in an office. Basically the ‘agents’ in the model can reasonably accurately mimic the real life occupants and make decisions about whether or not to turn on a fan, heater, or open a window based on their current thermal comfort levels and sensations. This is really important work to see published.
  • Jiao et al, ES&T, Field Assessment of the Village Green Project: An Autonomous Community Air Quality Monitoring System – cheap air quality sensors, low cost air quality monitors, or whatever you want to call them are HUGE right now. It really seems like people want to know what they’re breathing and want to be able to understand it accurately and inexpensively. It’s a sort of holy grail for any field. This paper reports a field assessment of a solar-powered air monitoring park bench that could measure ozone, PM2.5, and meteorological parameters and stream the data to the public. They were able to collect a bunch of data in Durham, NC, and had relatively decent correlations with nearby federal equivalent method (FEM) monitors (in English: regulatory monitors). Very cool.