Embodied Carbon of Shading v MEP

Shading of fenestration is often made of metals, including additional structure, and thus have high embodied carbon. However, shading can reduce the size, cost, and embodied carbon of HVAC systems and supporting electrical and plumbing systems. They can also reduce energy use a bit, although their energy use operational carbon reductions are often not communicated fully or well. Has anyone has studied shading devices for their positive or negative embodied carbon impacts on a project, considering the shading and the MEP systems…? I’d love to see what you came up with.

Kjell,
This may not be the information you are looking for, but I think it is worth pointing out that solar gains, properly controlled by shading when necessary, can entirely eliminate the need for a mechanical heating system. Passive cooling can do the same for mechanical cooling systems. There are a number of historic homes that achieved such performance. I am living in a house that is almost entirely conditioned by solar gains and ventilation cooling. I will be doing a presentation on advances in this technology for the Greenhome Institute Dec 4 at 12EST if you are interested: https://givebutter.com/FreeHeatGHICEUWebinar

I also have publications on applying ambient space conditioning to homes across US climates. Let me know and I can send them to you.

Regarding shading, my house has fixed overhangs to provide seasonal solar gains for some windows, and removable aluminum-framed panels of fabric (like a window screen) that reduce solar gains to a Trombe wall. For my house, a little extra embodied carbon eliminates all operational carbon associated with heating and cooling. It is a worthwhile trade-off.

Hi Kjell - have you seen the ULI report KPF did on whole life carbon of facades? It touches on shading devices: The Carbon Sweet Spot | ULI Knowledge Finder.

The key takeaway on shading devices is “Shading devices may increase total carbon emissions but significantly reduce peak loads. When using exterior shading, it can be strategically designed to optimize reduction in operational emissions while using less material.”

Thanks, Lauren. That’s the kind of report I was looking for!

I had an intuitive sense of their conclusion, but it’s good to see that backed up by numbers.

Kjell Anderson FAIA, LEED Fellow
Principal, Director of Sustainable Design

LMN Architects
lmnarchitects.com

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