HVAC systems can consume as much as 30 percent of a building’s energy usage… even modern HVAC systems. How can you get them to consume even less energy in order to reduce your operations expenses?
The answer lies in controlling your HVAC system according to real-time demand. When it comes to looking for places to trim expense, your HVAC system can be a prime target to cut costs.
When you take a walk through your office space, you can’t help but notice how much space is empty. That’s not only because of the pandemic. The changing nature of the mobile workforce was reducing office space occupancy even before March of 2020. Yet the traditional HVAC system pumps out heated or cooled air regardless of whether or not anyone is even using the space.
Demand-controlled HVAC is not just about using programmable thermostats or other building automation time-of-day schedules to turn the HVAC on during typical work hours and to set back at night. New technology can take this concept much further: creating zoned spaces that occupants can control according to their comfort needs, and even detecting when people are actually occupying each individual space in your office, and adjusting those modern HVAC systems accordingly.
Read on to learn about three components of modern HVAC systems that can help you significantly decrease your facility’s energy expenses.
1. Add air flow control with VAV boxes
VAV boxes or terminal units allow the occupants of your office space to be more comfortable while decreasing your energy usage. Older systems simply pump the entire volume of conditioned air into your space. Modern HVAC systems incorporate VAV boxes into the design, which use controlled dampers to vary the quantity of supplied air to control the temperature within a specific zone.
A VAV box is installed in the ducts near the outlet for each zone of your HVAC system. When people get too warm in a conference room that’s filled to capacity, adjusting the thermostat opens the dampers to allow more chilled air into the room. In a corner office where the sole occupant may be too cold, the VAV box receives the signal from the thermostat and closes the dampers down to reduce the amount of cool air flowing into the space. The result is customized cooling and a reduction in energy use, since the system does not need to run constantly and dump its full capacity of cooled air into the space.
2. Increase comfort and save energy with under floor air distribution
Another way to provide customized comfort, while decreasing cost, is to consider under floor air distribution for new construction. In this type of distribution method for modern HVAC systems, the conditioned air runs in a plenum space under a raised floor (typically 12 to 18 inches above a concrete slab) rather than in ducts overhead. In some cases, fan-powered terminal units and ducts may also be used under the floor. The air reaches the occupied space via diffusers in the floor.
Under floor distribution is more efficient, partially due to the natural thermal stratification of air and partly because the source of air is closer to where the people are instead of many feet over their heads. Under floor distribution can allow you to use higher thermostat setpoints for modern HVAC systems because of the increased efficiency. This newer ventilation method works well for open plan offices, especially because the raised floor can also accommodate power and computer network cables.
Related article: 4 Reasons You Need HVAC Design for Your Air Conditioning Install
3. Use occupancy sensors to control modern HVAC systems
If you have been investigating ways to save energy in your facility, you may already know about lighting sensors. These electronic sensors detect the presence of people in a room and turn the lights on and off according to when the space is actually in use. With today’s building automation technology and modern HVAC systems, these lighting sensors can be integrated with the HVAC system to control heating and cooling according to actual occupancy as well as the lighting.
Until recently, installing lighting sensors was something you could only consider when designing modern HVAC systems for new space or when undertaking a major renovation. That was due to the need to hard-wire the sensors directly to light sources in each room. However, wireless sensors are now available that are quick and much less expensive to install, without the need for wiring.
Occupancy sensors and modern HVAC systems: how it works
When the occupancy sensors detect that a space is unoccupied, they send a signal that turns off (or turns down) the flow of conditioned air to that particular zone of the floor or building. Estimates of energy savings vary, but can reach 30 percent or more depending on the typical occupancy of your space, the sensor technology you choose, and design of modern HVAC systems in place.
Lighting sensors use a variety of technologies to detect occupancy in a room or space: passive infrared (or PIR) which detects movement, magnetic sensors on doors, as well as cameras and microphones. Other types of occupancy sensors use low energy Bluetooth to track people’s locations in a space. Each of these technologies has its strengths and challenges. For example, there are often privacy concerns around using cameras, and whether doors are open or closed doesn’t always accurately predict room occupancy.
To get the most benefit from using occupancy sensors integrated with modern HVAC systems to reduce HVAC energy consumption, start with areas in your space that that are used intermittently throughout the day, such as conference rooms or classrooms, and choose the sensor technology that works best for your space and usage.
4. Don’t forget regular maintenance for modern HVAC systems
Even brand new modern HVAC systems need to be properly maintained from the start to get the most energy efficiency from the system. The trick is to use a qualified HVAC company that has the expertise to properly configure your equipment and keep it running as expected.
Related article: Facilities Managers: 8 Things to Look for in an HVAC Company
If you are in the process of researching newer, more modern HVAC systems for your commercial space, all the new technologies on the market today can make the process overwhelming. It can be a challenge to figure out what is the best option for your type of business, location, and energy usage requirements if you’re not an expert. Since we are experts, we’ve put together this free guide that can help: The Ultimate Guide to NYC Light Commercial Air Conditioning.