What is operational efficiency?
Operational efficiency is the measurement of how much energy a building actually requires in proportion to how much money you plan to spend on energy for the building.
What is a building envelope?
A “building envelope” refers to your building’s structure and the climate controls within it. The envelope separates the outside environment from the inside, and unfortunately, it often has flaws.
What are phantom loads?
Phantom loads (sometimes called plug loads), are caused by leaving electronics plugged in when they are not in use, and can contribute up to 10% of your overall electric costs.
What is an HVAC?
The heating, ventilation and air conditioning (HVAC) system is usually one of the biggest areas of energy consumption within a facility. An HVAC system is comprised of ductwork and registers, fans and blowers, and various electrical connections.
Imagine you are walking past a building on a warm summer’s day. You feel cool air blow on you, but there are no visibly open doors or windows. This is a sign that the building is losing energy. Unfortunately, air leaks are just one of the ways in which buildings can lose energy, thereby affecting their operational efficiency. In this article, we’ll examine the most common ways in which buildings lose energy and the corresponding steps you can take to limit wasted energy and improve your operational efficiency.
There are two notable methods of pinpointing energy loss: real-time data monitoring and thermal imaging. With real-time data monitoring, data from your meters is sent to your energy management platform, from which you are able to view your building’s energy use at regular, frequent intervals. If there is a spike in data, you will be alerted to the problem. Meanwhile, thermal imagers measure infrared energy or heat, then generate images showing where they detect it, assigning colors based on the temperature differences. If energy is escaping from the structure of your building, or from systems within it, the thermal imager will detect it.
What is Operational Efficiency?
Simply put, operational efficiency is the measurement of how much energy a building actually requires in proportion to how much money you plan to spend on energy for the building. For example, if your energy budget for the year is $200,000 but your building is consistently losing energy, then you will spend more money, use more energy, and have an inefficient building. However, if your building uses the same amount or less energy than you budgeted for, it’s likely that you are not losing a significant amount of energy to air leaks, programming issues, or phantom loads. Operational efficiency is especially important today; many investors, consumers, and clients value energy efficiency in the companies they have relationships with, and many states and cities are requiring buildings to meet certain efficiency standards.
Problem: Air Leaks
A notable amount of energy loss is temperature related. Hot or cold air leaks from a building are obvious examples. Energy was required to heat or cool the air, and when it escaped due to a leak, that energy was wasted. When air leaks out of your building, more uncomfortable outside air must be brought in, and you must pay to condition the new air. That’s why it’s important to keep the air you’ve already conditioned securely inside your building.
Solution: Examine Your Building’s “Envelope” Via Thermal Imaging
A “building envelope” refers to your building’s structure and the climate controls within it. The envelope separates the outside environment from the inside, and unfortunately, it often has flaws. Thermal imaging scanners can help you to catch these flaws. Since the degree of temperature variance may be miniscule – only one or two degrees – the best time to do your inspection is during a heating or cooling season, when the temperature outside is at least 50°F or 10°C higher or lower than the temperature inside the building. Additionally, be cognizant of environmental factors which might distort or conceal problems. For example, do not inspect an exterior wall that is in full sun or a roof that is covered in water or ice.
Some of the most useful places to conduct the thermal scan are:
- Roofs. Scan the roof surface and follow temperature differences to possible entry/exit areas for conditioned air.
- Walls between conditioned and unconditioned spaces, such as outside walls. Concentrate on the top and bottom of conditioned spaces and also look for indications of missing or wet insulation, which loses it’s effectiveness.
- Construction joints and connections. There are often heating or cooling losses by conduction through floor slabs that extend outside of the building.
- Penetrations of the building envelope. (Pipes, conduits, chimneys, etc.). Uninsulated gaps usually exist around roof and wall penetrations.
Thermal imaging is most effective when performed by people who have a good working knowledge of the structure and systems being scanned and can accurately interpret the temperature variances they see. You may want to ask your building’s engineer to perform the inspection.
In some cases, you can manually check for energy losses. Common air leakage points to check include:
- Windows and doors. One of the quickest ways to solve leaky air is to check for gaps around windows and doors. In older facilities and buildings, it is common to have drafts around the bottom of doors or the edges of windows. Draft guards and weatherstripping can be used on doors to tighten them up.
- Ceilings. The majority of air leaks occur through cracks near ceiling fixtures, like lights and fans. A difference in air density known as the “stack effect” causes a natural suction of air though the top of a building and outside air through the bottom of the building. To avoid this phenomenon, seal any cracks in the foundation and make sure the ceiling is adequately insulated.
Have you stood near a light and felt heat radiating off it? This is a sign that the bulb is burning through a significant amount of energy. If the lighting systems in your building are old and inefficient, you may be losing a great deal of both energy and money. Some estimates state that lighting accounts for more than 40% of electricity use in offices, stores, and other commercial buildings. A complete rehaul of your building’s lighting system can produce significant returns on investment. However, there are more simple fixes you can make.
Solution: Install Efficient Bulbs and Dimmers
Both LED and CFL bulbs can increase your building’s lighting efficiency, and both are compatible with dimmers. It is common knowledge that turning off lights in unoccupied rooms is key to saving energy. However, installing dimmers on your building’s light switches can add another layer of electric savings. Dimmers reduce the wattage and output of the bulb, while simultaneously increasing its life span. Better yet, dimmers are inexpensive. Before you purchase new bulbs, keep in mind that because CFL bulbs contain traces of mercury, they must be specially recycled. LEDs are a bit pricier, but they are now subsidized by Ngrid.
Additionally, because lighting is one of the largest uses of energy in buildings, real-time data monitoring can be used to detect inefficiencies or verify the efficiency of new lighting. Does the data indicate that your lighting system is consuming more energy than normal for the time the lights are on? Did your daily energy use fall dramatically after installing dimmers? These are a few of the questions real-time data monitoring will help you answer.
Problem: Phantom Loads
In previous blog posts, we discussed peak loads and their effect on energy costs. However, phantom loads (sometimes called plug loads) caused by leaving electronics plugged in when they are not in use, can contribute up to 10% of your overall electric costs. With many offices and some residential buildings operating at drastically reduced capacity during the coronavirus pandemic, phantom loads could be affecting your building’s operational efficiency more than you suspect.
Solution: Turn Off and Unplug Appliances
Leveraging efficiency can help reduce your energy costs. Turn off appliances in your building like televisions, desktop computers, printers, and refrigerators. However, since most devices will never turn off completely when they are still plugged in, unplug them so they cannot continue to draw power. Encourage any people using the building to unplug equipment before they leave for the day. Smart power strips also help reduce phantom loads, since they only power plugs when a device is actively turned on and in use. Finally, real-time data monitoring is a useful way to pinpoint phantom loads. If the data shows unusually high energy use when your building is vacant and lights and devices are supposedly off, this is a sign that phantom loads are draining your energy.
Problem: Faulty Controls
The controls on your heating system can have flaws that cause unnecessary energy spikes. For example, improperly functioning heat pumps operating solely on back-up heat sources can increase your heating costs by much as 40%. Boiler controls should also be regularly examined to ensure they’re running correctly.
Solution: Use Energy Management Software to Monitor Data Spikes
In many cases, a spike in energy use will be the first indication you receive that there is a problem with your system controls. In order to be instantly alerted to changes in data, it’s important to have energy management software that provides you with real-time data monitoring. With real-time data monitoring, data is collected from your meters daily, hourly, or in 15-minute intervals and then sent to the energy management software. If any abnormalities occur, you will be able to fix them immediately, rather than wait for them to appear on your utility bills (and negatively impact your operational efficiency).
Problem: HVAC Systems
The heating, ventilation and air conditioning (HVAC) system is usually one of the biggest areas of energy consumption within a facility. An HVAC system is comprised of ductwork and registers, fans and blowers, and various electrical connections. All of these can be areas where energy is lost.
Solution: Inspect the HVAC System
You can use both manual and thermal techniques to inspect the efficiency of your building’s HVAC system. With infrared thermal technology, you can see the air loss or gain in the duct work. In the fans and blowers, inefficiencies will show up as overheated bearings or other components. Thermal images can also reveal shaft misalignment between the motor and fan. Electrical connections, meanwhile, can usually be inspected manually. Be on the lookout for loose or corroded connections – they increase resistance at the connection, leading to overheating and energy loss. Additionally, real-time data monitoring can be used to determine the status of your HVAC system. Since the HVAC should not be shut off entirely even if your building is vacant during COVID-19, continually high energy use could be a sign that the system is not running efficiently.
Problem: Motors and Generators
Electrical motors use up of the large amount of energy budgeted for a facility. Overheating and malfunctioning motors and generators can be indicative of mechanical or electrical inefficiencies that can lead to more energy use (and in worse case scenarios, system failure). The best ways to reduce your motors’ energy use are to keep motors well maintained, size them appropriately and operate at them constant speeds. Generators are essentially reverse motors, so diagnostics are similar. Consider examining:
- Airflow. In motors cooled via fans, a restricted airflow can cause overheating which manifests itself throughout the entire building.
- Electrical imbalance. Use thermal imaging to detect a high-resistance connection in the switchgear or the disconnect or motor connection box. This is the usual cause of the imbalance. You should also scan the components of rotating equipment, especially the bearings and shaft.
- Bearings. Use thermal imaging to scan the bearing, looking for bearing housings with suspiciously high temperatures. This indicates that you must either lubricate or replace the bearing.
- Electrical connections. As you did with the connections in HVAC systems, look for loose or corroded connections that could be increasing resistance.
Problem: Steam Heating Systems and Boilers
Today, steam systems are more common in industrial settings (like factories) than commercial settings. However, some commercial buildings still use steam for central heating. In New York City, for example, steam is one of the major sources of power.
Solution: Examine the Systems and Check for Leaks
Like any system, steam heating is prone to leaks. Consider inspecting the following areas of the system:
- Steam traps. You can check traps using thermal technology to see where energy is escaping.
- Radiator coils. Check for leaks using a similar method to the one used on HVAC ducts.
- Steam lines and valves. Look for telltale signs of leaks and blockages, e.g. air or steam escaping from valves that are supposedly “closed.”
- Condensers. Search for leakage of outside air. This reduces the strength of the condenser’s vacuum, thereby decreasing its efficiency.
Boilers are the heart of your building’s steam and hot water heating systems. Consider examining:
- Refractories. With thermal imaging, you can monitor the condition of the refractory linings.
- Leakage of outside air. Thermal imaging is best for diagnosing this issue, which can cause substantial inefficiencies in your building’s operation.
- Casing insulation. Heat can be lost due to damaged insulation.
- Fan motors. Like you did with the motors in other applications, check for blocked airflow, electrical imbalances, overheated bearings and faulty insulation.
- Pumps. Be on the lookout for hot bearings, leaking seals and faulty motors.
- Valves. Use thermal imaging to detect blocked valves should be open or leaking valves that should be fully closed.
- Electrical connections. Similar to other systems, check for any loose, corroded connections.
Problem: Electrical Systems
Did you know that electrical systems can actually waste money? As the system ages, components will inevitably degrade, leading to increased resistance and incremental waste of energy.
Solution: Check for Imbalances and Overheating
Most energy losses in electrical systems will occur around the distribution panels, transformers, and lighting control circuits. Check for imbalances in circuits and loose and corroded connections at breakers, contacts, fuse clips, busses, and the like. Monitor high- and low-voltage bushing connections, and cooling tubes, fans, and pumps. Search for overheated connections, cool cooling tubes and hot or cool pumps. If the temperature of one electrical leg on a transformer is significantly hotter than the others, that leg may be failing. (You can check the temperature using thermal technology). Finally, examine all wiring splices and connections at fuses, switches, and fixtures. (Thermal technology can also be used to scan low-voltage control circuits).
Minor Problems and Their Solutions
- Toilet leaks. Surprisingly, any toilets in your building are prone to inefficiencies. Monitoring your water data is a great way to discover spikes in water use. Use real-time data monitoring to keep an eye on the numbers.
- Furniture placement. Because many heating systems work through convective loops, furniture placement (like a couch placed in front of a radiator or a side table placed over a vent) can reduce your heating system’s efficiency. Take some time to check where your building’s vents and radiators are in relation to where furniture or other potential impediments are situated.
In order to properly scan your building for inefficiencies, it is important to acquire a thermal imager. In recent years, thermal technology has decreased markedly in price. Within a relatively short time period, your company can make up for the cost of purchase through energy savings. Incorporating thermal imaging into manual checks of your building will allow your engineers and maintenance team to identify problems and fix them before your operational efficiency is negatively impacted.
Additionally, energy management software (like EnergyWatch’s WatchWire program) is vital to making your building more efficient. Not only can WatchWire provide you with real-time data monitoring (as mentioned above), it can assist you with preparing energy budgets, measure your water and energy use, help you measure and verify the effectiveness of your efficiency projects, and benchmark your efforts against national efficiency standards like WELL Building and ENERGY STAR. To learn more about WatchWire’s capabilities, download the WatchWire Fact Sheet.