Tenant Engagement Series: Automation and IoT
By EnPowered - January 19, 2021
Your energy plans are only as good as the building you're in. Infuse your property with smart tech to save money, cut emissions, and attract tenants. EnPowered simplifies energy management.
Read the rest of our Tenant Engagement Series for more insights
HVAC energy efficiency can be improved by installing smart sensors that track metrics such as static air duct pressure and room occupancy in order to fine-tune performance
Installing centralized command hubs allows building operators to take a holistic approach to energy efficiency and share energy data with tenants
Reducing the need for lighting by using reactive windows (tints, blinds etc.) and automated sunlight management can lead to significant energy savings
We're often told to think ‘outside the box’, but when it comes to improving your property’s energy efficiency, thinking ‘inside the box’ - namely inside the building - can actually lead to substantial savings. Decreasing a building's energy carbon intensity is an important goal, but equally important is maximizing the potential of the energy use, regardless of its source. Investing in energy efficiency not only benefits the planet, but even simple changes to a building can save a bundle.
There’s a massive list of potential retrofits and upgrades that you can undertake to improve your energy efficiency, so for the sake of efficiency we’ll focus on HVAC and lighting, two of the biggest sources of energy use. In the US, commercial buildings account for 18% of total primary energy use and emissions, as well as 36% of all electricity used in the country. Electricity accounts for 61% of all energy used in commercial buildings, of which HVAC uses 33% (although this can be over 40% at least as one-third of buildings have oversized HVAC systems for their size) and lighting 17%.
According to the American Council for an Energy Efficient Economy (ACEEE), “smart building owners and tenants enjoy non-energy benefits along with [...] energy savings. Tenants are increasingly demanding flexible, controllable workspaces, and some building owners are installing smart technologies to attract and retain tenants.” Alongside this growing demand from tenants, the steady downward trend in tech prices makes installing smart systems more appealing than ever. For instance, a simple Internet of Things (IoT) sensor (like the gyroscope sensor in your smartphone) cost $1.30 in 2004, and less than $0.60 in 2014.
Smart systems can help reduce load during Peaks and limit consumption in unoccupied spaces and buildings. Building managers use such systems to tailor equipment performance to prevent unnecessary wear-and-tear and energy waste. Smart systems also provide building managers with real-time data instead of outdated, month-old meter data. Regarding HVAC, optimizing the amount of conditioned air (whether hot or cold) is one of the largest energy windfalls in terms of efficiency and savings that retrofits provide. A quick example is the use of duct static pressure sensors to determine the amount of resistance faced by directed airflow. The higher the pressure, the harder equipment has to work to shift air around, so using these sensors can let managers configure HVAC systems to work more efficiently at different pressures.
“smart building owners and tenants enjoy non-energy benefits along with [...] energy savings."
Using CO2 level sensors can help whole-building control systems control CO2 levels in occupied spaces by modulating airflow in one place without starving or over ventilating other areas. A key idea to keep in mind is multi-zone variable air volume (VAV), as systems that take this into consideration can monitor and optimize HVAC settings in individual rooms, such as in a hotel. Hotel rooms are usually left at whatever temperature the previous guest or staff member set them at, so by using occupancy tracking solutions building managers can stop wasting tens of thousands of dollars on heating and cooling unused rooms. This is an important area for improvement, as only 30% of hotels globally use such systems.
For example, the Conrad Hotel in Chicago managed to save over 450,000 kWh per year after installing automated HVAC controls, infrared sensors, and wireless door switches. The investment also paid for itself in 1.5 years, thanks to more than $35,000 in annual savings. Similarly, after Adobe instituted a new open-plan office layout at its headquarters it installed an automated system to shut down HVAC and lighting use in areas that had been unoccupied for more than 15 minutes. This project reduced energy consumption by 65%, while the number of employees working in the space grew, from 80 to 135.
All those additional employees would have added to the energy drain from workstations and equipment in Adobe’s office - a common phenomenon familiar to many businesses. The use of smart or advanced power strips (APS) is one way that companies can reduce their energy use. These devices can be programmed to automatically shut-off devices at a certain time, for a certain time, or when a predetermined load threshold is reached.
While plug load (energy used by plugged-in devices) accounts for 5% of total energy use in commercial buildings, it is often one of the last areas tackled in efficiency drives. Plug load in high-performance (read highly efficient) buildings can contribute to up to 50% of energy use. Therefore, installing smart plug systems is nothing to sniff at and is among the cheaper options for companies looking to improve their energy use.
“sub-metered plug load data can be shared with tenants to inform them of their energy use and allow property managers to bill tenants accordingly”
Another benefit of APS is that “sub-metered plug load data can be shared with tenants to inform them of their energy use and allow property managers to bill tenants accordingly,” notes the ACEEE. APS have been shown to reduce energy use by workstations by 26%, with 24/7 loads benefiting the most (a 48% decrease in energy use) from APS installation.
APS can be just one part of a centralized control system that includes HVAC and lighting (among others) to provide holistic energy management plans. For example, Stanford University has installed a system that monitors 1,220 variables to create predictive models of the institution’s energy use 7 days in advance. The system is projected to save the university $420 million over the next 35 years.
Another exciting example is Bank of America’s Intelligent Command and Control Center created in 2009 and networks 3,000 branch offices to monitor and remotely control lighting and HVAC. This set up allows the command centre to remotely alter the lighting and HVAC settings of branches in different states or across the country.
Alongside HVAC, lighting is a major source of energy consumption, but fortunately there is a wide range of options available to reduce your lighting overhead. When it comes to lighting, smart lighting is the hottest game in town, with the number of smart lighting installations exploding from 46 million in 2015 to 2.54 billion in 2020. You’ve probably heard of high efficiency or LED lighting options, which can reduce energy use by 30% compared to traditional light bulbs. Still you may not have realized that by combining LEDs with advanced lighting controls you can reap an extra 14% in savings.
"An element many overlook is using daylight to negate the need for lighting in the first place."
Building a wireless lighting system controlled through IoT tools is 50% cheaper than installing lighting systems with traditional wall mounted controls. One of the coolest ways to build smart capabilities into a lighting system is to use a Power over Ethernet (PoE) system. You can connect LEDs by using the same kinds of cables initially designed to replace traditional landlines and enable internet telecommunications (such as VoIP). These cables bundle low voltage DC power (which LEDs can use but traditional bulbs cannot) and internet access in one, a perfect combo for smart lighting systems. You can easily run the cables through ceilings in any direction and as an added benefit you won’t need to worry about AC to DC power conversion through a driver or ballast.
An element many overlook is using daylight to negate the need for lighting in the first place. Using smart window sensors and things like automated blinds or special window films to reduce the need for artificial lighting can make a substantial difference. For example by employing such tools with sensors that monitor indoor light levels, you can take advantage of daylight and reduce lighting use by 40-80%, without compromising tenant satisfaction.
Managing daylight is doubly important because you can also enjoy more HVAC savings if done right, as 33% of HVAC energy use in commercial buildings is in response to heat loss or gain from windows. According to the California Energy Commission, in hotter climes, this can be even higher: 40% of typical cooling requirements in Californian buildings are due to solar heat gain from windows.
This means that not only are multi-pane windows and proper insulation obvious musts for any sensible building manager, responsive daylight management systems are also vital temperature regulators. Take a look at the New York Times Building, which combined many of the elements we’ve already discussed; integrated window shading, dimmable lighting, task-level tuning, and daylight harvesting, to reap lighting savings of 43% and overall energy savings of 24%.