A Letter to Architecture from MEP Engineering

Can we talk about refrigerants and a few other things that keep us up at night?

by Kayleigh Houde
Associate Principal and the global Computational Projects Lead at Buro Happold

Dear Architect,

It’s me again, MEP Engineering, your overly analytical cousin (that you love being sat next to at the Thanksgiving table.) I know I’ve made things complicated in the past regarding my doggedness on the climate change movement, but I’m changing my ways — I promise. If I have your ear again, could you try to listen? After all, the systems I create help your building occupants stay well with filtered outdoor air, stay comfortable in ambient conditions, avoid straining their eyes by delivering power to those beautifully curated light fixtures, find their way to safety in the event of a hazardous event, and enjoy the convenience of indoor plumbing.

Regarding climate change, I have taken an active role and responsibility for the many ways that MEP systems are involved in this complex puzzle of operational, embodied, and fugitive emissions in the built environment.

From acting as my partner on projects, you may have noticed the juxtaposition of passive (building thermal envelopes – facades and their insulative properties) and active systems (our MEP systems.) This same concept applies to embodied carbon and operational carbon. I’m now constantly faced with these convoluted trade-offs, if I choose to drill 850 feet deep into the earth with a geothermal heat pump well, will the materiality (embodied carbon) from the heat pump, piping and grout as well as the construction emissions balance the operational energy savings of the heat pump over its lifetime?

Speaking of high-impact carbon decisions, the fugitive emissions from refrigerant choices for our cooling systems weigh heavily in our decision making process (just one kilogram of R-410A can have a global warming impact of around 2000 kilograms CO2 equivalent per kilogram!) However, there are a number of factors that I’m now faced with in this refrigerant decision. First, if I want to choose a lower global warming potential refrigerant for my equipment, will it be available in the United States? Second, will its lower carbon content be overshadowed by the fact that if it’s not a ‘natural’ refrigerant, then it may contain fluorine and may therefore have health consequences (particularly in the case of R-1234yf.) Third, is it flammable (surprise, propane makes quite a nice refrigerant) and last but not least, does it have an equivalent efficiency?

These are the things that keep me up at night. It’s not that simple, when you’re looking after thousands of small parts that all have meaningful trade-offs with other systems.

Enter MEP 2040, a group of engineers, architects, and owners working to address whole-life carbon in the built environment. The group started in 2021 as a movement to radically reduce total carbon emissions associated with building systems through collective action. The group has built a community of more than 90 signatories and 46 supporting organizations dedicated to closing knowledge gaps through quarterly forums and fortnightly working group meetings. Their open-source Refrigerant Impact Tool allows designers to make better choices when it comes to the global warming impact of refrigerants. Their work with the ECHO Project is allowing key industry initiatives to progress toward the creation of a single, harmonized carbon reporting schema. MEP 2040 is also working to create a guide for quantifying MEP embodied carbon, an area that has been sorely missing in Whole Building Life Cycle Assessment, in North America at least.

We remain optimistic that through our many collaborations and meaningful conversations that we can move forward together faster. Please join us for our next MEP 2040 Quarterly Forum, or join as a signatory or supporting organization at MEP2040.org.