How Building Energy Efficiency Helps Improve The Air Quality In Cities

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Air pollution has a great impact on the health of the society and environment, and has been linked with many health-related issues including respiratory and cardiac illness, so it is of utmost importance to find the best ways to reduce it. Recently, a Harvard study revealed that COVID-19 mortality increases in regions with high levels of air pollutants. When we read the term “Air Pollution”, we tend to think about air pollution associated with traffic. However, there a much bigger source of emission that gets overlooked. The transportation sector accounts for 28% of Greenhouse Gas (GHG) emissions, while the building sector contributes for 40%.

Building emissions are mainly categorized into 2 types, direct emission and indirect emission. Diesel generators and natural gas boilers account for the direct emission while the electricity consumption from power plants that burn fossil fuels account for the indirect emissions. Reducing air pollution with effective energy efficiency methods is proving to play a vital role in building sector. When buildings improve their energy efficiency, all the emissions are collectively reduced to a great extent.

Importance of an Energy Audit

Energy audit is systematic collection and analysis of energy data which is used for identifying both, where and how the energy is used, and also the potential for saving energy. Optimal combination of energy efficiency measures varies for different properties depending upon the consumption profile. The best starting point is to opt for a professional energy audit which will allow the building owners to understand the financial returns of all the potential upgrades beforehand. This will also help owners to avoid measures that might not be suitable or effective for the building.

The audit provides 2 critical pieces of information:

Energy savings per dollar invested.
GHG emission avoided per dollar invested.

Generally, upgrading boilers and old furnaces running on heating oil can help achieve the best results. This reduces the heating cost as well as the emission per BTU (British Thermal Unit). Upgrading building heating systems can be costly but the energy bills overtime would eventually offset the cost while ensuring environmental profits.

Depending upon the building location, emission reduction may help qualify for a clean energy grant or a low interest loan. Properties over 25,000 sq. ft. in New York will be subject to emission reduction law starting from 2024.

Switching Energy Sources to Cut Emissions

Energy emissions are considerably cut down when buildings switch to energy efficient measures. In US as of 2020, building owners can claim 26% federal tax credit for renewable energy investment after switching to solar power. Switching from oil fired boilers and furnaces to natural gas fired units will lower the emissions per BTU of heat delivered.

Building owner also have an option of going 100% electric and eliminating site emissions by using high efficiency heat pumps. In case of indirect emissions, fossil fuels dominate the power grid and concentrating emission at a power plant is still preferred over directly emitting them in cities. However, indirect emissions can be reduced automatically with building electrification if the local grid starts using a greater share of renewable energy.

For a better understanding, assume a building uses 100,000 kW-hours per month where the power grid produces 0.8 kg on CO2 equivalent per kWh. In this case, indirect emissions are 80,000 kg CO2 eq per month. But, if the grid reduces the emission intensity to 0.6 kg CO2 eq per kWh, the indirect emissions are automatically lowered to 60,000 kg per month.

Now using electricity for space heating and hot water may not feasible for some buildings but, switching from heating oil to natural gas may cut down the emissions by almost 50%. What that means is that energy expenses and greenhouse gases (GHG) can both be reduced simultaneously with energy efficiency.