Passive First – Active Second – Renewables Last
It is well documented in the construction industry that building energy use accounts for 41% of total energy use in the Unites States. This opportunity creates an exciting time for anyone engaged in the built environment. New and innovative materials and equipment labeled “green technology” emerge daily and are marketed to change the way we do business. The search continues for the smoking-gun that will fix our energy consumption problem. As we implement the latest technologies, I can’t help but ask; Does this help us reach our goal of true sustainability? Does this impact climate change? Are we, in the AEC community, doing enough to reverse emission trends? The answer to me is obvious – No. The mere existence of ESCO, ESPC, and Sustainability Consultant businesses are sufficient proof that Builders and Designers have room for improvement.
When we look at buildings, we see a complex object operating dynamically. Changes to individual energy conservation measures typically do not result in directly proportional reductions to total building energy consumption. However, changes to groups of energy conservation measures typically have a compounding impact on reduction to total energy consumption. Where do we start? As it turns out, the smoking-gun is the process of how we design, build and use buildings.
This inspiration resulted in the creation of Energy Assurance™. A building-specific Energy Assurance™ plan is a game changing methodology that provides building owners the control necessary to measure and, more importantly, manage a building(s) energy consumption. Energy Assurance™ develops Energy Utilization Intensity (EUI) goals for the purpose of dramatically reducing energy consumption and delivering short, medium and long term financial returns. In most cases, Energy Assurance™ has 2-3 year payback periods, but can be customized to meet the client’s financial needs.
One of the keys to Energy Assurance™ is its commitment to the Natural Order of Sustainability, which is an energy methodology of Passive First – Active Second – Renewables Last. The Natural Order of Sustainability is a biophilic treatment of buildings as a living organism. Natural processes and designs are the standard to which we aspire. A subsequent benefit of Energy Assurance™ is that it creates an organic pathway to reach net-zero energy consumption.
Maximizing passive strategies first will reduce loads for heating and cooling systems, thereby requiring smaller and more efficient active solutions for mechanical systems. Utilizing natural triggers of new and retrofit construction make this cost feasible. Common passive building principles to optimize energy balance through the building envelope are continuous insulation, airtight compact building shape, thermal-bridge free envelope, high performance windows and doors, optimal solar orientation, shading and modest window areas to optimize moderate solar gains.
Active strategies to reduce energy consumption for heating and cooling are most effective when mechanical equipment is decoupled. Logically, planners will optimize passive space conditioning solutions as a core strategy. Common passive space conditioning solutions include an independent balanced mechanical ventilation system with heat and moisture recovery and pre-conditioning. This strategy will maximize a constant and filtered fresh air supply. Remaining peak loads can then be solved by implementing highly-efficient active systems. Active systems implemented using the Natural Order of Sustainability will be smaller due to passive load reduction strategies. Lastly, planners are challenged to manage internal loads with efficient appliances, HVAC, plumbing and lighting systems which minimize sensible and latent loads and internal gains.
Building owners who believe renewables are the smoking gun are quickly discovering that the return-on-investment for a renewable based energy efficient strategy is not financially sustainable. Passive building strategies lower the amount of operating energy in a cost effective manner by applying conservation measures first. In this way it is practical to supply all of a building’s energy needs with relatively low levels of renewable sources. Renewables in the Natural Order of Sustainability are used to offset or zero-out remaining energy consumption and carbon emissions of buildings as final strategy. Then, photovoltaic arrays and wind farms are more affordable due to their decrease in size and first-cost.
The Natural Order of Sustainability is logical. As critical enablers continue to emerge; like energy dashboards, energy disclosure ordinance, and whole building energy modeling, planners will begin to realize the hidden solutions to net zero. Net zero is possible without a financial premium and sacrificing thermal comfort using the Natural Order of Sustainability.
The Natural Order of Sustainability requires vision and patience. Optimizing life-cycle and construction triggers to implement passive strategies requires Energy Master-Planning and leadership to deeply reduce energy consumption.
The smoking gun is the process, which begins with the Natural Order of Sustainability.
For more information on Energy Assurance™, refer to http://www.jamesco.com/construction-services/high-performance/