Energy efficiency has been a primary goal of the SLAM project since its inception, and recent engineering efforts have led to some exciting discoveries. The project is unique in that it must carefully manage both sensible heat (what you feel) and latent heat (moisture in the air). A constant temperature and humidity range is vital to protecting the treasures housed in the building. The extremes of Juneau’s Alaskan maritime climate mean that the building’s mechanical systems must be constantly working to maintain this balance.
There are many sources of heating/cooling loads in SLAM, but the two that contribute most to energy usage are heat transfer through the building envelope and tempering of outside air needed to maintain a healthy indoor environment for artifacts and people. The SLAM team has been working diligently to design a robust building envelope that greatly exceeds the baseline requirements of the International Energy Code. Simultaneously we have been finding ways to ‘recycle’ energy within the building so it is not lost to the environment. Heat recovery ‘wheels’ are proposed for all five outside air handlers. These wheels have the capacity to recover up to 80% of the energy that would otherwise be lost to the outdoors.
The baseline heating system includes electric and oil-fired boilers that can adapt to the most economical source of energy. With this redundancy the building is able to maintain a stable environment even if one of the fuel sources goes offline due to unforeseen circumstances. The baseline heating system also anticipates a future connection to district heating. Willoughby district landowners are currently working together on a study that looks at the feasibility of a bio-fuel fired district heating plant. When this plant comes online SLAM will be ready to connect to it via a simple heat exchanger.
In a few weeks a test well will be drilled on site to make a final determination on the feasibility of seawater cooling and heating for the building. Seawater holds promise to meet most of the sensible cooling needs of the building, and seawater heat pumps hold promise for supplying the lower temperature heating systems in the building, specifically radiant slabs on the first floor and snow melt systems on the parking access ramp.
Updates will be provided on this blog as these exciting developments mature.