Almost a quarter of the energy used to run our commercial buildings could be saved with some relatively simple and inexpensive efficiency measures.
In New Zealand, commercial buildings account for around 9% of total energy use and 21% of electricity use. The latter costs New Zealand businesses around $1.25 billion every year. About $280 million of this could be saved, cost-effectively, through energy efficiency measures.
Opportunities to reduce energy consumption in existing buildings have been under-publicised for a variety of reasons. The most notable is a lack of available cost data. Other reasons include lack of clarity on the appropriateness of certain technologies and their respective energy savings, a perceived level of disruption to occupiers and the ‘who pays, who gains’ issue between landlords and tenants. EECA Business has been doing a huge amount in this area to plug those gaps (www.eecabusiness.govt.nz).
The majority of office buildings (built prior to 2002) can achieve a significant energy reduction following a small additional spend of 5% when undertaking a major refurbishment. Of course refurbishing buildings and improving their energy efficiency adds tangible value to the asset, in terms of market value, but also increased occupant comfort (translating into a more desirable asset).
With office buildings, one of the best places to start identifying where the opportunities for efficiency savings will shortly be to get a NABERSNZ™ rating. NABERSNZ is an energy performance rating tool being launched in June that will provide building owners with a star rating (from 1 to 6) and a sense of where they sit compared to the rest of the market. It’s an initiative being launched by EECA Business and the New Zealand Green Building Council (NZGBC) to measure and rate energy performance in the office market, with a view to extending to other types of building in due course.
EECA’s experience working with companies that have undertaken energy audits indicates that typically 5% to 20% of energy can be saved through no- and low-cost changes. These changes include tasks such as improving building management practices and re-commissioning building services systems (see below).
The utopian ideal would be that we design and construct our buildings for maximum efficiency (NZGBC also operate the Green Star suite of tools to help early encourage this – nzgbc.org.nz) and that we dare to believe that our buildings can also give back to the environment, through exporting surplus energy to the grid. Easy wins’ for businesses trying to lower their energy bills
Improve building management
First, you need to understand how your building works. Then ensure your facilities/property manager is monitoring the building operations and energy use, and putting in steps to correct any anomalies as they occur. This also involves educating tenants and other building users about simple energy saving measures, such as turning off lights and computers when not in use. I recommend a building user guide to help with this. Lighting controls:
A well-designed building should offer its tenants the maximum amount of daylight possible to reduce the load on the lighting services; however, we know this isn’t always possible. So, we advise simple measures such as lighting zoning (lights switched on only where and when people are working), appropriate
lux levels for the space and the most energy efficient fittings and fixtures you can afford (remember LED and T5 lighting have great payback periods).
Improving air tightness All buildings leak a little, but a great thermal envelope ensures heating and cooling efforts don’t go to waste. Vasriable speed heating and cooling pumps:
This type of heating and cooling system allows for variation depending on the conditions. It ensures that your heating and cooling functions according to what it needs to achieve, rather than operating at the same levels all the time. Heating controls:
Just like lighting, different spaces need different levels of heating throughout the day. Efficient zoning and designing for the user’s needs helps reduce energy use and avoids heating or cooling an area that isn’t being used. Avoid reheating. This is where a building is heating air in a zone that was previously cooled by the central services. Ask your facilities or property manager if this applies to your office. Other easy wins to talk to your building manager about: Power factor correction High-efficiency chillers Heat recovery DC drive fan coil units Introducing economy cycle into air conditioning systems Efficient boilers