Improving Energy Efficiency With Retro-Commissioning
Retro-Commissioning is a process of Improving The Energy Efficiency of a building’s equipment and systems that consume Energy. It is also a vital part of Compliance with Local Law 87 of 2009 set out by the New York City Department of Buildings. Before we move on to the benefits of Retro-Commissioning, we need to understand what it is.
Retro-commissioning (RCx) is the application of the commissioning process to existing buildings. The process allows building owners to reduce energy usage and bills by restoring the building’s operations and maintenance (O&M) procedures. It can often resolve problems that occurred during design or construction, or address problems that have developed throughout the building’s life as equipment has aged, or as building usage has changed. Retro-commissioning involves a systemic evaluation of opportunities to improve energy-using systems. If the same process were applied to a car, mechanics would adjust the settings, controls, components, and design of the engine based on how the owner drives. Thus, it is a vital part of Improving Energy Efficiency.
How is it Applicable to Building Owners in New York City?
NYC Local Law 87 of 2009 mandates that buildings larger than 50,000 square feet are required to file an Energy Efficiency Report with the Department of Buildings. This Energy Efficiency Report includes details of the energy audit results and retro-commissioning measures.
An energy audit is an inspection, survey, analysis, and report of energy flows to improve energy efficiency in a building. It will study the base buildings systems, such as the building envelope, HVAC (heating ventilation and air conditioning), conveying systems, domestic hot water systems and electrical and lighting systems. While Retro-Commissioning is a detailed look at how well HVAC and lighting controls are working.
Benefits of Retro-Commissioning
Retro-commissioning is beneficial for both building owners and occupants. Some of its key advantages are as follows:
Energy and Cost Savings
Retro-commissioning is a form of conservation that directly aligns with a reduction in energy use and can widely produce significant cost savings. According to the U.S. Department of Energy, retro-commissioning can result in 5% to 15% energy savings. Peak energy efficiency translates directly to decreased greenhouse gases and supports sustainability objectives.
Improved Indoor Air Quality
When a building lacks adequate ventilation, humidity control, significant air filtration, or air purification, the indoor air quality can drop. Retro-commissioning is sometimes implemented to increase HVAC system performance to ensure ventilation rates and humidity control are optimally functioning, thus providing better indoor air quality for occupants.
Better Temperature Comfort
Temperature control is energy-efficient and cost-effective. But building inhabitants might not feel the increase in comfort unless the heating, ventilation, and air conditioning system properly circulates the heated or cooled air. Poorly performing systems could create hot or cool spots throughout the building. A more organized system can minimize these uncomfortable spheres, ensuring that individuals in the building can feel more comfortable wherever they are.
Efficient Productivity or Safety
Improved comfort levels can also contribute to improved productivity levels for building employees. Moreover, when lighting levels are enhanced for maximum productivity, workers can concentrate more on their work rather than being distracted by flickering or insufficient lighting.
A commercial lighting retrofit is vital to keeping people in a building secure. Poor lighting can hide obstacles and increase the risk of injuries. Well-lit places where lighting is needed contribute to the safety of the occupants in a building, as they help people see any potential hazards in front of them by enhancing visibility.
Extended Equipment Life
When HVAC systems or lighting function ineffectively, the life spans of equipment go down. For example, an HVAC system that is forced to operate continuously or has a lot of component cycling to maintain a set temperature will wear out at a faster rate than a system that experiences steady-state operation at reduced capacity. Retro-commissioning improves the efficiency of the whole building so that building managers will not have to replace parts or entire systems earlier than needed.
Reduced Repair Needs or Warranty Claims
When equipment frequently requires repairs or warranty claims, operators must reflect that the system needs reassessment and alteration to perform more effectively. Incompetent functioning can lead to parts failing prematurely, and the building administrator may need to submit a warranty claim frequently. Retro-commissioning could eliminate the necessity for consistent repairs or part replacements outside standard upkeep.
Cost of Retro-Commissioning
The cost of retrofitting a building’s systems varies significantly depending on the facility’s attributes. Factors influencing the expense include the structure’s type, square footage, existing efficiency, and other traits. Consulting a qualified retrofitting professional provides a customized assessment for a building.
The U.S. Environmental Protection Agency calculates the average retrofitting project for a structure yields $0.27 saved per square foot and a 15% reduction in energy usage. This combination means recovering the cost of retrofitting within 0.7 years. Naturally, the precise payback timeline hinges on the initial investment required. Some retrofitting methods necessitate longer periods to earn back expenditures yet still furnish benefits as savings accumulate monetarily over time.
When considering the cost of retrofitting, don’t overlook the financial savings in utility bills and the non-monetary advantages for the building. Boosts in productivity and occupant comfort can help increase profits or rental fees within the facility. Lower maintenance expenses reduce repair and part replacement outlays, and enhanced safety cuts down on workers’ compensation claims. These non-energy cost savings benefits still make retrofitting a worthwhile investment for existing buildings.
Step-by-Step Breakdown of the Retro-Commissioning Process
The retro-commissioning process can be divided into 4 stages, including the following:
1. Planning
To ascertain whether a building is an ideal candidate for retro-commissioning, a team of experts first seeks to identify high-energy-consuming equipment or systems that need frequent repairs. They will also identify systems that frequently cause occupant complaints about temperature, relative humidity, and indoor air quality.
Next, the experts will check the building size and equipment age and collect all the required documentation. Then, the owner’s operating requirements are considered to establish a plan for possible enhancements.
2. Investigation
The project team will review facility documentation, such as drawings and control sequences of operation. This also involves investigative and testing procedures, such as running functional diagnostic tests and low-cost repairs. The team will also perform diagnostic monitoring of operating characteristics, such as utility meters, temperature and relative humidity, building indoor air pressures, and carbon dioxide levels.
They will create an aggregated master list of findings to serve as a decision-making tool. Recommendations that can be implemented are selected from a cost-to-benefit analysis of energy-saving options and operational improvements.
3. Implementation
The next phase will focus on creating an implementation plan and scope of work based on the master list of findings. The team will then identify operational or capital improvements with the help of both outside contractors and in-house staff. The group will test the updates made for expected outcomes. A summary report will be created outlining all the actions undertaken.
4. Verification
The verification stage is the last stage of the retro-commissioning process. The team will set up recorders and monitoring equipment, including utility meters, temperature and relative humidity recording tests, operating conditions, and other diagnostics.
A final report of the retro-commissioning activities and measures undertaken shall include a master list of findings, updates of energy savings estimates, performance improvement results, recommended re-commissioning frequency, complete documentation of all measures, and a list of additional improvements that can be made.
Benefits of Retro-Commissioning
Retro-commissioning benefits everyone in a building. Building owners see reduced operating costs from the energy savings and better equipment performance, leading to an increase in net operating income. It is also vital in compliance with the NYC Local Law 87 of 2009 which is required by buildings in NYC that are 50,000 sq. ft. and up.
Building occupants are more comfortable because the adjustments lead to more consistent temperature control and better indoor air quality. Building managers, meanwhile, face fewer occupant complaints and are better able to manage building systems.
Following are some of the key benefits to be realized through retro-commissioning:
- Improved occupant comfort and productivity.
- Improved Building Operation.
- Improved Building Systems Efficiency and Extended Equipment Useful Life
- Documented Building Condition and Deficiencies.
- A List of Recommendations for Improvements.
- A Road Map for Capital Improvements.
- Potentially Reduced Carbon Footprint.
Building Energy Efficiency Certification
Participation in RCx programs may help building owners qualify for, or improve, green building rating certifications, such as Energy Star and LEED. The Cotocon Group will lead you through the steps required to make the complicated certification process easy: from Energy Audits, energy evaluation to the Certification application process and maintenance.
