401 West Georgia

The existing and potential green building operation strategies were assessed to generate a gap analysis of the facility’s performance. Using LEED Canada’s Existing Building: Operations and Maintenance (EB:O&M) program as a roadmap, the project undertook building performance improvements and implemented several new policies.

LEED EB:O&M consists of nine prerequisites and optional credits that can be pursued to earn up to a total of 110 points. Certification brings the value of actual performance measured against a three-month operations baseline period with a year of energy data. Projects must re-certify every five years in a process of continuous improvements.

Water Efficiency

An initial water performance measurement showed that flow rates of showers, taps, and urinals could be adjusted to decrease water use by over 25%. Shower flow rates were reduced almost in half, from 12 Lpm to 5.7 Lpm. Lavatory aerator flow rates were cut by over 72% (from 7 Lpm to 1.9 Lpm), and urinal flush rates were reduced to 1.9 liters per flush, down from 3.8 Lpf.

Cooling tower management is not only a water issue but, if improperly managed, can become an indoor air quality and occupant health issue. A water management plan for the cooling tower at 401West Georgia was put in place to address training and maintenance as it relates to chemical treatment, bleed-off, biological control. To improve water efficiency and maintain proper chemical rate and concentration, a conductivity meter was installed.

Outside the building, water savings were gained by reducing irrigation on landscaping through the use of native, adaptive and drought tolerant plantings.

Energy

Finding energy savings in an office tower with multiple complex systems needs to be a comprehensive endeavour to maximize impact.

A Retro-commissioning Investigation Report was created for 401 West Georgia was put in place for its major systems. A breakdown of energy use in the building was produced through investigation and analysis. Recommendations were provided for implementation and recommended verification methods to demonstrate each measure would be implemented correctly. The information in a retro-commissioning investigation report can be used by an owner to specify corrective actions and what needs to be presented to show that the improvement has been successfully implemented and are a key map for success.

Investigations for this project focused on low-cost improvements with short paybacks, with major capital improvement opportunities also identified. With the cost-benefit analyses presented, the following measures were presented to the developer, which were either implemented over the EBOM performance period or identified for implementation over the next few years:

Optimized Sequence of Operation on Building Automation System (BAS)

While a large number of the building’s controls were pneumatic, Automated Logic Direct Digital Control (DDC) was available for most of the ventilation systems, heating hot water and domestic hot water systems, and lighting systems. Knowing that a properly sequenced HVAC system can reduce energy consumption by 1-2%, the building owner worked with their controls contractor to review all control sequences and update control drawings to serve as As-Builts, which are now available on site for easy reference. Once documented, control sequences were reviewed to create additional optimized sequences. Through this process, it was discovered that the project had two separate sequence of operation documents from two separate contractors. In addition, neither document had a sequence of operations to describe how the Multistack Heat Recovery Chiller operated in relation to the heating or cooling system. Another opportunity for sequence optimization was the chilled water system, which consisted mostly of points that were programmed to operate at a fixed set point.

Over-Ventilation Correction

Calculations on ventilation relative to fan capacity showed that the make up air to tenant floors to comply with ASHRAE 62.1 could still be met while reducing the capacity of the ran and rebalancing the fresh air system.

To test this, Oxford had CO2 monitors installed to track the Indoor Air Quality on a floor-by-floor basis before reducing the ventilation. Here the project is gaining more accurate building data and making better energy saving decisions based on that data.

Installation of More Efficient Heat Exchanger

The building at 401 West Georgia had an older shell and tube type of heat exchanger. These have an estimated life cycle of 24 years. The replacement plate type heat exchanger is more efficient, easier to maintain and is capable of recovering latent heat for even greater efficiency.

Air Handling Unit Damper Repair

During functional testing of an air-handling unit, it was discovered that the Fresh Air Damper (FAD) would not close completely, allowing air to escape from the building during unoccupied hours. This caused higher than normal heating loads in the wintertime due to the stack effect caused by high temperature differentials between inside and outside the building. The general exhaust fan’s Exhaust Air Damper (EAD) was also not closing properly, causing hot air from to escape from the opening in winter months. These dampers were replaced for

Simultaneous Heating and Cooling Correction

During the heating season, when the building’s chillers are off, the commissioning team observed that cooling control valves were still open for interior and perimeter fans. Fan systems with open cooling valve during building heating mode creates a situation of simultaneous heating and cooling. This inefficiency was corrected by reprogramming the BAS to isolate the cooling coil when in heating mode, and the sequence of operation was revised by commanding the cooling control valve to be fully closed (0%) when the building is in heating mode.

Heating Water System – Building Freeze Protection

The steam valve based on existing sequence of operation opened during unoccupied hours whenever Outdoor Air Temperature (OAT) was less than or equal to 4°C. The commissioning team determined this could be lowered to 0°C. Diagnostic testing taking place in December showed that space temperatures were between 14°C to 18°C even when Outdoor Air Temperature reached -5°C. It was determined that operating the heat pump when OAT is less than or equal to 0°C can result in steam and electricity savings.

Making this change was as easy as creating a setpoint on the Building Automation System to enable building freeze protection when OAT is less than 0°C and sequencing the heat pump to operate when freeze protection is activated.

Other low-hanging fruit (low cost energy efficiency measures) taken on include:
-Insulation of domestic cold water back up system for prevention of condensation issues
-A loose fan belt was discovered and tightened on one of the air-handling unit for improved motor efficiency and energy savings
-A reset schedule was created for the seasonal operation of make up air units, which were running too high
-Data logging showed the inside of one of the air handling units rose to 20 degrees Celsius when the unit was off, trying to maintain plenum temperature. The same air-handling unit now has its cooling coil isolated when in heating mode, revising the sequence of operation to command the cooling control valve to fully close when the building is in heating mode
-To ameliorate constant, simultaneous heating and cooling in the transformer room, thermostat was reset to start up heating when temperature dropped below 12 degrees Celsius and to start cooling when room temperature rose above 27 degrees Celsius. A ducted fan schedule was also reset. The resulting optimized heating and cooling schedule yields energy savings and prevents over-use of mechanical equipment
-Fan systems and floor fans schedule were revised for winter and summer when it was discovered that the systems started too early

These efficiency measures not only cut kWh’s and BTU’s, they cut greenhouse gas (GHG) emissions as well. To measure these successes in tons of carbon, Oxford Properties now tracks and records its emission reductions delivered by their energy reduction measures.

Material and Resources

401 West Georgia created a waste reduction, reuse and recycling program to address durable goods such as office electronics, appliances, external power adapters, etc. with the goal of reusing and/or reducing 75% of durable goods in the waste stream during the performance period. The project’s contracted waste hauler is tracking on-site waste, with a reported 3/4 of ongoing consumables being recycled.

Additional successfully reached goals on waste diversion for 401 West Georgia include:
-An ongoing consumables waste diversion rate of at least 70%
-Collected and appropriately disposed of least 95% of all used fluorescent lamps, including CFL’s
-Collected and properly disposed of 80% of batteries discarded from the building
-Diverted 70% of waste generated by facility alterations and additions from disposal to landfills and incineration facilities

Indoor Air Quality

During the renovation, the protection of Indoor Air Quality was crucial. Teams must be vigilant to ensure that particulates and contaminants associated construction activities do not affect occupant health. To prevent indoor pollutants and to control at the source, an IAQ Best Management Plan was created, which included the requirement to conduct a pre-construction meeting to present to all contractors and subcontractors with the plan and requirements, which were reinforced at construction progress meetings.

Proper ventilation is another key to indoor air quality and thermal comfort. To ensure ventilation performance was met with existing air-handling units, outdoor air volumes were calculated, with flow rates checked at each air intake to ensure outdoor air is delivered as per the ASHRAE 62.1 2007 standard.

Can a doormat improve Indoor Air Quality? If it is a well-maintained system, yes, it can. Permanent walk off grates were installed at the lobby entryway to prevent dirt and other pollutants from entering the building. To further prevent airborne contaminants at entryways, tobacco smoke is prohibited a minimum of 7.5 meters from the building’s entrances.

What building owners can do

For building owners who recognize the long-term financial value of a green retrofit, gathering data is key. Anthony Esposti, Senior Manager of Corporate Financing at Business Development Bank of Canada says energy-saving fixtures usually pay for themselves within two to six years. In order to ensure that retrofits actually deliver those savings, building owners need the following pieces of information:

• Baseline data on the building’s energy and water use before the retrofit;
• Recommendations on equipment to reduce baseline use;
• Projected energy reductions and cost savings, as estimated by an engineer
• A means to collect and monitor data on the building’s energy and water use after the retrofit

A number of consulting companies provide this type of service, but financing for existing buildings can provide a challenge to pay for these services with the recommended equipment upgrades. Esposti advises landlords to inquire about retrofit financing options with their current lenders. Using information on the benefits of green buildings from sources like the Canada Green Building Council and Natural Resources Canada may aid in a loan request.

BDC is currently looking into ways to assist entrepreneurs reduce their companies’ greenhouse gas emissions and increase energy efficiency. Esposti also urges building owners to contact Business Development Bank of Canada with regard to financing as they “do have money available for doing things aside from mortgage financing.”

What you can do at home
There are countless measures a homeowner can take on to reduce their environmental impact and increase energy efficiency. Below are a few with references to other resources for even more information.
Energy
The top four upgrades a homeowner can do to improve energy efficiency are:
-Improve insulation levels in the attic, walls, and basement
-Upgrade to a high efficiency Energy Star-rated heating system
-Upgrade to a high efficiency hot water system and install low flow
showerheads and faucet aerators
-Weather strip and air seal your home to make it as airtight as possible, while also adding proper ventilation systems

Homeowners can work with a Certified Energy Advisor, who is certified by Natural Resources Canada to deliver energy efficiency services and perform air leakage testing of homes. A CEA can provide a benchmark of your home’s performance and provide guidance on how to make gains in efficiency for greater comfort, savings and environmental responsibility.
To learn about additional benefits and tips on being more energy efficient, consult the City Green Solutions website, a British Columbia energy efficiency social enterprise. There is also a section on provincial incentives for home efficiency upgrades: www.citygreen.ca/incentives

Reduce your carbon footprint at home

Create an estimate of how many tons of carbon dioxide and other greenhouse gases your household’s choices create each year. There are several carbon footprint calculators, including this one from the Nature Conservancy
-Keep your bicycle in a well-maintained condition for one less excuse to ride to your destination; a bike pump at home means you can maintain tires at recommended PSI levels for easier pedalling.
-If you’re not already vegetarian, make a point of reducing your meat intake, particularly red meat even by one meal a week. Cutting meat can slash your food-related carbon emissions to almost 50%.

Sources: Oxford Properties, MMM Group, Business Development Bank of Canada