A Window into China’s Building Energy Use

Nils Petermann, Efficient Windows Collaborative at the Alliance to Save Energy

Shanghai in December

Last December, as cold spells were about to strike the northern hemisphere, I sat at meetings in Shanghai to discuss plans for implementing window energy labeling. As we talked about standards for window insulating values, I noticed the irony of the situation in that the windows in our room were partly opened – in the middle of December.

Shanghai buildings are traditionally not equipped with heating systems, and it is common that windows are opened for ventilation. By North American standards, the temperature can be called freezing, but we kept warm with jackets and hot water and tea.

The Impact of A/C

So why the fuss about window energy performance? Air conditioning is one answer. Almost nonexistent in China before 1990, air conditioning has now become almost universal in Shanghai and other major metropolises. Now, most Chinese are more conscientious in their AC use than most Americans are, but in a country with >1.3 billion people and rapidly growing urbanization, you can figure the electricity supply crunch.

Much of the heat that air conditioning removes comes through window glass. So when distinguishing between transparent glass that invites plenty of heat and transparent glass that reflects heat, energy labeling proves very useful.

Insulating Pocketbooks

But it isn’t only air conditioning for cooling that causes the interest in window energy labeling. From the Yangtze River southward, air conditioning is now often used in the reverse for heating too. Shanghai is just south of the Yangtze. The reason we didn’t have heat during our meeting was because open windows and ventilation were preferable in a room full of people.

North of the Yangtze, central heating is supplied in most buildings. So far, much of this central heating still comes without thermostat control; so for individual households, whether the windows are energy-efficient or not is purely a comfort issue and does not affect the volume of heat supplied.

But that is changing too: individual metering and individual controls are emerging due to heating reform, so better insulation is starting to become a pocketbook issue for residents.

Getting Creative

My understanding of the changes in heating and cooling energy use in China is incomplete, and language barriers will make it difficult for me to stay up-to-date on these development.

But I do understand that expectations of thermal comfort in China are becoming more similar to what we know in North America. They may never resemble the American obsession with keeping indoor temperatures the same throughout the year, but still – given China’s population and urbanization, the increase in heating and air conditioning demand is unprecedented anywhere and anytime else.

To cope with this demand increase, energy efficiency experts have to be creative. Window energy labeling is only one small piece in this puzzle. The Energy Foundation’s China program, which funds our assistance to China’s window labeling program, works on energy efficiency strategies for various aspects of China’s buildings sector. To anyone interested in the sustainable construction movement in China, I’d recommend the Green Dragon Film project, an exciting introduction by three young filmmakers to the Chinese and international players behind that movement.

Can the creativity of energy efficiency experts and entrepreneurs realistically steer China’s construction sector to greater sustainability? Or will such efforts remain prestige projects atop an iceberg of huge new energy liabilities? We cannot know for sure yet, but I’d be very interested in your experiences, views and expectations.

Tags: China, energy-efficient building technologies, standards and labeling

This entry was posted on Friday, April 2nd, 2010 at 10:09 am and is filed under Buildings. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.