HVAC represents the largest share of energy consumption, almost 50%, in most building including residential and commercial. Energy bills rise considerably in winter due to the additional demanding heating and cooling requirements. Although, an increase in the energy bills is expected, an excessive cost may require attention to the building’s HVAC systems.
The 3 main factors that affect the heating costs in winter are:
- Space heating system efficiency
- Building envelope efficiency
- Proper configuration of thermostat setting
Some other energy consumption issues are improper insulation and air leaks. With these issues prevailing, even the most efficient thermostat will increase energy consumption and lead to higher heating costs.
Let’s take a look at the 3 most common energy consumption issues during winter and how you can fix them.
Air Leaks in the Building Envelope
Space heating systems are intended to maintain the required temperature and promote thermal comfort in indoor spaces. In presence of air leaks, the heating systems have to overwork which makes the task of regulating thermal comfort more difficult. In simple words, air leaks allow cool air to enter, which makes the space heating system work more than intended. This increases the energy bills considerably.
While some air leaks are obvious like near windows and doors, some air leads are difficult to find. To effectively identify air leaks, it is recommended to consult to energy consultants. The 2 most popular ways of identifying air leaks are:
- Thermal Imaging – It’s a powerful tool that identifies cold areas and reflects them visually by assigning a darker color that their surroundings. Thermal imaging also detects poorly insulated areas in building envelope, even when there are no air leaks present.
- Pressurization Test – This test enables building owners with an estimation of leakage in cubic feet per minute (CFM). The blower door test is also one of the most common ways for detecting air leaks, where the air in injected or extracted and the effect on indoor pressure is observed.
Heating Systems with Low Efficiency or Poor Maintenance
In most cases, low efficiency is due to lack of maintenance or technological limitation of old equipment. To creating the most effective plan to tackle low efficiency is to get a professional inspection from HVAC engineers.
A professional building inspection reveals some common maintenance issues like damaged insulation of air ducts or hydronic pipes that hamper the heating efficiency. These issues are not complex and can be handles with minimal disruption in building operations. In some cases, a simple upgrade can resolve the energy efficiency issues. It is thus recommended to perform an inspection to identify the best possible solution with minimum investments.
Based on a research by the US Department of Energy, a setback of 7 – 10 degree Fahrenheit for up to 8 hours per day can reduce the HVAC costs up to 10%. In winter, most thermostats are set at high temperature, which makes them consume more energy. Since individual preferences may vary, finding the ideal setting for a building is always a challenge.
However, a study by Lawrence Berkeley National Laboratory found that the optimum temperature for high human productivity is between the range of 21 to 23 degree Celsius. In addition to this, the WELL Building Standard recommends a temperature variation of 3 degrees Celsius for offering better thermal comfort.
Apart from thermostat, other equipment settings that affect heating performance are boiler pressure, damper positions, ventilation rates, air duct pressures, operating schedule, etc. A professional energy audit can help detect these issues.