VOX–The Green New Deal aims to get buildings off fossil fuels. These 6 places have already started. The nation’s capitol has taken some incredibly ambitious steps on climate change. Last December, it passed some of the strongest clean energy requirements in the country.
On the morning of Tuesday February 12th, 2019 Hickok Cole helped facilitate the inaugural session of the DMV Net Zero Coalition. Presented by DCRA’s Green Building Division, and Arlington and Montgomery counties, the coalition was a chance for multi-disciplinary building industry professionals from across the region to share progress on achieving deep energy savings in their buildings and share best practices in designing Net Zero structures.
With over 130 attendees, the coalition was a great success and gets us one step closer to the goal of creating a grassroots regional peer-exchange network that promotes and builds capacity for net-zero energy buildings and technologies throughout the greater Washington region. This coalition will be ever more important now that DC has mandated 100% renewable electricity sourcing for the city by 2032.
A special thanks to Dave Epley, DCRA’s Green Building Program Manager, Joan Kelsh and Jessica Abralind of Arlington’s Office of Sustainability & Environmental Management, and Lindsey Shaw, Montgomery County’s Energy & Sustainability Programs Manager for organizing this coalition kick-off. If you would like to included in future events, please contact DMV.NZE@gmail.com.
- Wednesday, April 3rd: Montgomery County Energy Summit at the Silver Spring Civic Building register click here.
- Wednesday May 1st: Bisnow’s Greater DC Solar and Sustainability Summit: Why Developers Should Go Green to register click here.
Be sure to follow the latest American Geophysical Union construction updates at Building AGU.
GREATER GREATER WASHINGTON–DC Mayor Muriel Bowser signed the most ambitious clean energy law in the nation on Friday. It requires all of DC’s electricity to come from renewable sources like wind and solar by 2032, 13 years earlier than California and Hawaii have committed to transition to 100% green electricity.
URBAN LAND MAGAZINE — In 2017, California passed the first net-zero building code in the United States. New York City; Washington, D.C.; and other cities have made net-zero building commitments as well, including both new and existing buildings.
ARCHITECT MAGAZINE — Harvesting the sun’s power to create net-zero (or even net-positive) energy is cheaper than ever now. So why aren’t more architects doing it? It probably comes as no surprise that solar power is currently the least-used energy source in the United States. It has had a lot of catching up to do.
Construction is now fully underway on The American Geophysical Union’s (AGU) headquarters renovation in Dupont Circle. As part of its mission of “science for the benefit of humanity,” AGU seeks to lead by example and is striving to create the first-ever “net zero energy” renovation of an existing commercial building in the District.
In order to realize this goal, particular strategies had to be devised and technological advances realized. We would like to present just a few of them from the architects’ perspective:
Solar Photovoltaic (PV) Array
This solar PV array includes 720 solar panels making up a 250 kilowatt system. It includes 24 panels on a vertical, south-facing surface and 696 panels laid out horizontally and elevated above the penthouse roof. The panels are from manufacturer Sunpower, and at just over 22% efficiency, they are some of the most efficient on the market.
Dedicated Outdoor Air System (DOAS) with Exhaust Air Heat Recovery
The DOAS will provide a dedicated means of ventilation for the building. This system will condition the air prior to delivering it inside, while at the same time recovering the outgoing exhaust air’s heat to help raise the temperature of the incoming fresh air for space heating needs.
Hydroponic Phytoremediation (Hy Phy) Wall
While this wall looks like a standard green wall or vertical garden, it will actually work a little harder. When installed it will be an active rather than passive wall, and function as part of the building’s ventilation system. In conjunction with the DOAS, the wall will filter and improve indoor air quality, all while reducing the amount of outside air necessary. The plants, their roots, and the water filtration system will scrub air of unwanted toxins and VOCs before it recirculates throughout the building.
Municipal Sewer Heat Exchange System
This system will tap into a combined sewer line in front of the building, which was built in the 1890s, to maximize the efficiency of the building’s mechanical systems. It will essentially function the same way a geothermal system does—as a heat sink/source—but it will be the first of its kind in the United States. The system operates by:
- Diverting wastewater to a settling tank located just outside of the building.
- Circulating the then debris-less water into a sewer heat exchanger in the underground garage.
- While in the garage, separately piped in radiant fluid will be pre-heated or cooled before being circulated throughout the building.
Fear not, it is a closed loop system, no sewage contamination will take place. Read more about how sewer heat exchange works here.
Stormwater Collection and Re-use
Rainwater will be captured from the roof and PV array and collected in a large cistern also located in the building’s garage. After filtration and treatment this greywater will be reused for all flushing fixtures and the irrigation of the green roof and hy phy wall. The cistern’s capacity is 11,300 gallons.
Enhanced Dynamic Glazing System
The existing windows at AGU will soon be removed and replaced with dynamic glass. The curtainwall glazing will be made up of triple-pane, air-filled, 1-3/4” thick windows. The added 3rd pane gives the windows a lower U-value and solar heat gain coefficient to help reduce the transmission of heat and cold. This glazing will also utilize an electrochromic film to tint the windows on-demand. This tint twill take the place of traditional blinds as well as reduce glare and heat transmission while still allowing natural light in and views out.
DC Powered Workspace and Lighting
The US electrical grid is wired for alternating current, or AC, power distribution. However, direct current, or DC, power is used by computers, appliances, and LED lighting. Conveniently, DC power is also what will be produced by the large PV array on AGU’s roof. Creating an energy distribution microgrid which relies on direct DC to DC power will reduce the energy efficiency loss caused by power conversion.
Enhanced Envelope Insulation
The existing building envelope is brick on a CMU backup wall separated by an air gap. The exterior walls do not currently contain insulation or an air/weather barrier. 6” studs have been added along the interior of the perimeter wall which will provide space to:
- Install 8” of closed-cell spray-applied insulation to achieve an R-value of 53. The new insulation will also act as an air barrier.
- Anchor new windows which will now be in-line with the insulation, creating a continuous thermal barrier.
Radiant Ceiling Cooling System
In a radiant ceiling system temperature is controlled by radiation, a more efficient way to condition space than forced-air. Decoupling the building conditioning system from the DOAS provides the opportunity to reduce the overall energy needed to move air through the building since it’s now only needed for ventilation, not for space cooling.
“The renovation of the existing AGU headquarters provides an unprecedented opportunity to challenge ourselves to lead by example and demonstrate that we, and the Earth and space science community we represent, can be a model for sustainable design, reducing the carbon and environmental impacts of business operations in a cost-effective and replicable way.”
– American Geophysical Union
Be sure to follow the latest construction updates at Building AGU.
Construction at the net zero renovation of American Geophysical Union’s (AGU) headquarters is getting really exciting – assuming, like us, you now find work on a 125-year old sewer line to be the pinnacle of your interests. Despite the images (and smells) the word “sewer” brings to mind, it turns out we’re not the only ones interested in the complex systems running below our busy streets. NBC Washington recently published a story on the ways DC Water is using innovation and inventions to lower customers’ bills, featuring the municipal heat exchange system currently being implemented at AGU. The system is the first of its kind in the US, using utility access to “use the sewer’s natural heat and lower heating and cooling costs.”
The investigation shares DC Water’s hopes that “other commercial customers will be interested in buying access to the sewer system to utilize [the new] technology,” and we have to admit that we’re completely on board. Despite the upfront investment required to make access possible, implementing municipal heat exchange systems throughout the District would help reduce the amount of energy used by buildings in the nation’s capital, and help reduce energy costs for building owners.
Sound too good to be true? Fortunately for us, and your future energy bill, it’s not. And in the coming years, AGU will serve as an example of the system’s potential impact, tracking and sharing energy data openly for all to see and learn from. In the meantime, we’ll get you started by covering the basics.
How does it work?
AGU’s updated building systems will tap into the 1890s-era sewer line, diverting wastewater to a settling tank in a ‘wet well’ located just outside of their building at the intersection of Florida and 20th Streets NW. The debris-less water will then be circulated into a sewer heat exchange system that will live in the building’s underground garage. This is where the radiant fluid for the building will be pre-heated or cooled before being circulated throughout the building. Fear not, it is a closed loop system. The murky water will be returned back to the sewer.
Using this strategy, AGU is able to maximize the efficiency of their building’s mechanical systems. So much so that there will be periods during the year where the building will operate in a ‘free cooling‘ mode and the building’s chiller will not be needed to provide supplemental cooling.
Why is this important?
All of this helps reduce AGU’s energy consumption, maximizes the resources on site, and helps the mission-driven organization reach its goal of a net zero energy headquarters.
Using the bathroom uphill from Florida Avenue will help cool the building – AGU thanks you in advance for your support.
Below are some photos of the sewer, located about 30’ below grade in Dupont Circle. All of those pipes and pumps are to re-route the um, flow, while work is underway.
While the first system of its kind to be implemented in the US, the municipal heat exchange is not the only “first” for this project. When complete, AGU will become the first net zero commercial renovation in the nation’s capital.
Want to learn more? Check out this video featuring AGU team member and Managing Principal for Interface Engineering, Roger Frechette. You can find more videos like this, and stay up to date on the latest construction updates from this ground breaking project, by visiting Building AGU.