This blog series is focused on different methods to evaluate and reduce energy consumption of buildings. The demand for energy is increasing at an alarming rate and the building sector is one of the largest consumers of energy; gaining more and more prominence over the past few decades. Retro-commissioning is a proven process to help combat this problem. Let’s start with a quick overview of what building commissioning is.
Commissioning is a quality assurance process that provides documented confirmation that a building is operating at optimum level of the owner’s requirements. Commissioning ensures that building systems are planned, installed, tested, operated and maintained the way the owner intended. Commissioning often provides:
• Increased energy efficiency
• Maximized occupancy comfort
• Extended life cycle of equipment
• Reduces O&M costs
During the retro-commissioning process, existing building systems are inspected for physical, functional and performance conditions. All issues are documented and presented in a comprehensive report to the owner. Diagnostic test equipment is used to assess existing equipment efficiency and operating characteristics. This analysis is used to identify opportunities for energy conservation. The retro-commissioning process usually occurs in four distinct phases as illustrated below:
A research study on commissioning and retro-commissioning performed by Lawrence Berkeley National Laboratory in 2009 found that the average retro-commissioning project cost $0.30 per square foot with energy savings of 16% and with a simple payback of 1.1 years. Which brings us to the glaring question, why isn’t everyone doing this? Some possible reasons could be unfamiliarity with the retro-commissioning process and fear of any upfront costs. In order to overcome these hurdles, many cities across the nation are recognizing the importance of retro-commissioning/energy audits and are developing legislation that makes it a mandatory procedure. For example, New York City has developed PlaNYC, an agenda to meet energy challenges to building a greener, greater New York. Included in this plan is Local Law 84: Benchmarking and Local Law 87: Energy Audits and Retro-commissioning. In my next blog, I will discuss these laws in detail.
Do you have any questions regarding retro-commissioning? Drop me a line in the comments section below!
American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) is accredited by the American National Standards Institute (ANSI) and follows ANSI’s requirements for due process and standards development. ASHRAE has helped to mainstream the integrity of commissioning by setting guidelines and criteria for the commissioning process. ASHRAE has also partnered with the United Nations Environment Program to drive their global effort in reducing the amount of pollutants released into the atmosphere by buildings. ASHRAE has created an international advisory team to assist developing countries in their goals to institute and revamp relevant codes and standards.
In terms of building commissioning and retro-commissioning, ASHRAE developed Guideline 0 – Commissioning Process and Guideline, which details the process, intent, activities and deliverables that should be followed to optimize benefits. This document has incited the development of numerous supporting guidelines and standards for the commissioning process. In addition, ASHRAE also defined best practices and created different levels of energy audits (Preliminary Analysis, Level 1, 2 and 3). If you are interested in learning more about these guidelines, visit ASHRAE’s website (https://www.ashrae.org). In particular, they have posted their Fall 2013 online courses here: https://www.ashrae.org/education–certification/2013-fall-online-courses. On October 9th there is a Commissioning for High Performance Buildings course and on November 4th and 6th there is a Commercial Building Energy Audits course.
As part of the PlaNYC initiative to have a more sustainable New York City, all buildings over 50,000 sf are required to file an Energy Efficiency Report (EER) with the New York City Department of Buildings (NYC DoB). This requirement is known as Local Law 87. The EER consists of an ASHRAE Level II energy audit and retro commissioning study of base building systems. Base building systems include systems or subsystems that use energy or impact energy consumption, including: building envelope, HVAC systems, conveying systems, domestic water systems and electrical/lighting systems. EERs are due to the NYC DoB once every 10 years starting this year. The EER reports are due in a staggered schedule, which is based on the last digit of the building’s tax block number.
Do you have any questions regarding ASHRAE and how they are involved with Local Law 87 legislature? Post them in the comments below. In my next blog, I will provide an overview of the second part of Local Law 87 compliance, retro-commissioning.
We’ve all been told as children – “Turn off the lights when you’re not in the room” and “Don’t leave the water running when you’re brushing your teeth.” Now, there’s so much more we can do to conserve energy and resources in our homes and businesses. There is heightened awareness that our “small and insignificant” actions collectively have great impact on the environment and personal/corporate budgets.
To know how much energy we spend (or waste); we need to assess the situation and come up with a baseline. Just like we all go to the doctor every year and take our cars in for inspection, our homes and offices need the same check-ups. Hence, the energy audit. In short, an energy audit is a way to determine the energy consumption of a building. These audits can help individuals see where money and energy are going out the window (sometimes literally). For one of our clients, we found they were using 2.28 times the average electricity and 1.65 times the natural gas for buildings of their type. We identified 15 Energy Conservation Measures totaling a possible savings of $615,000 and approximately 30% reduction in energy use. These audits help identify troublespots in the property and methods for improving the building’s performance. Alterations can be as simple as changing light bulbs or as complex as overhauling the heating and cooling systems.
Being efficient is more than saving money; it’s about preserving our natural resources and minimizing our impact on the environment. Many elite corporations are leading the charge by greening their business practices and supply chains. They’re educating their employees on how to make eco-friendly decisions. Further, they’re investing in their buildings via retrofits and even building according to green standards such as LEED.
Building green is booming because this generation demands socially responsible corporations and healthful work environments. Unfortunately, some still cite heavy upfront costs as an obstacle to building green – materials are more expensive, the LEED process comes with additional costs and it just takes more planning and innovation.
Great ideas, innovation and progress come from challenging situations fraught with limited resources. In the case of building green, the financial aspect is favorable to the cause. A USGBC-funded study of LEED buildings in NYC found that there was no significant price differential for construction costs between LEED and traditional buildings. According to the analysis, the average construction cost for a LEED high-rise residential building was $440/sf and $436/sf for non-LEED. I think an extra $4/sf investment is worth it, especially since the returns include better air quality, lowered utility bills, increased productivity and less pollution-spewing buildings.
If we’re going to tackle the looming issue of global warming, we need to take one conscientious step at a time – whether it’s turning off the light, doing an energy audit, investing in a retrofit or starting from scratch and building green.
The USGBC recently launched its new program (v.03) that includes recertification of buildings each year. In addition, the LEED-EB program has a recertification component that must be completed annually. There has been an uproar in the green building industry arguing that a building is not just about energy consumption, but also the types of construction material used, site selection and occupant comfort.
I agree that material selection and indoor environmental quality is just as important to getting a building certified as being energy efficient. However, let’s not kid ourselves in thinking that a building that fails to remain a good steward of the environment should continue to hold the privilege of being called a green building. A building that drastically consumes more energy than when it was originally certified has issues that require investigation. Sadly, the green has wilted away and has turned brown.
Let’s look back at why we call it sustainable building. Sustainability focuses on constructing a building that efficiently consumes energy, water and other resources with minimum impact to occupants and the environment. How a building consumes energy and expunges waste contributes to its carbon footprint. Current technology does not allow for buildings to operate fully on clean energy; therefore, existing buildings continue to leave huge footprints causing irreversible damage to the environment. It should be every building’s goal to keep its footprint to a minimum by performing proper maintenance on its systems and constantly monitoring its energy patterns to identify opportunities for conservation.
Optimal building sites, sustainable building materials and healthy indoor air quality are important characteristics for green buildings and should be incorporated into the certification process. These factors should be considered at the baseline and are unlikely to change significantly overtime. However with daily use, a building’s systems and equipment may come out of sync, become old, outdated and inefficient, resulting in greater consumption of energy and increased waste. Without constant vigilance to determine how much energy these buildings consume on a daily basis, we cannot guarantee that these buildings are living up to their green labels. Without these requirements for energy monitoring, I agree with critics who favor decertification of buildings who fail to meet LEED standards following their initial certification.
The LEED certification process says a lot about how building owners view energy. Following a comprehensive design, an energy model should be performed to predict how the building will function. But it shouldn’t stop there. I’ve seen companies brag about their supposed “LEED-certified” buildings, screw the plaque onto their pristine walls before commissioning is completed and actual building performance is validated. What message is the USGBC sending when they give certifications out before performance is verified? There is no value to the plaque if a building doesn’t measure up to LEED standards from the beginning or throughout its lifecycle.
I have requested the USGBC to modify its program during revisions in LEED-NC 2.2 and my suggestions fell on deaf ears. If the USGBC will not change its policy on certifying new buildings prior to validating its energy consumption, then I say grab the screwdriver and uninstall the plaque after the first year if the building doesn’t meet Energy Star requirements. This may sound harsh, but we must have integrity and make sure our buildings perform as we say they do.