Commercial buildings rely on multiple systems to function properly and include equipment such as lighting fixtures, air handling units, compressors, boilers and pumps. To ensure high performance and provide occupant safety, the New York City Department of Buildings requires commercial buildings to comply with a series of building codes, as shown below:
- New York Plumbing Code
- New York Mechanical Code
- New York Combustible Gas Code
- New York Building Code
- New York Energy Conservation Code
Engaging the services of qualified engineers is the best way to ensure code compliance. In the case of new buildings and major renovations of existing buildings, this is generally not a problem because code compliance is mandatory before the building can begin operating. On the other hand, systems in existing buildings may deteriorate over time, falling below the minimum standards established by applicable codes; The consequences of this may include decreased performance, higher operating and maintenance costs, and unsafe conditions for occupants.
Even if building systems are functioning correctly, an assessment can help detect areas of opportunity to improve performance; The saying that “if it ain’t broke, don’t fix it” doesn’t apply here, as technology is constantly evolving and there are always opportunities to improve construction systems.
1) Lighting Installations in Commercial Buildings
Lighting installations are among the most important systems in commercial buildings, for the simple reason that adequate visibility is necessary for commercial activity and human safety. The following are some common lighting problems that can decrease productivity and compromise safety, requiring an engineer's attention:
- Flickering light bulbs – A flickering light source can be extremely distracting in commercial environments, also causing eye strain. This problem tends to be more common with older fluorescent lamps powered by magnetic ballasts, although modern light sources can also be affected, especially if there are power quality issues. If your installation has flickering light bulbs, have an engineer inspect them to determine the exact cause.
- Buzzing – This can also be distracting and is especially common with magnetic ballasts, which are used with HID lamps and older fluorescent tubes. Buzzing and flickering often occur together.
- Color Distortion – This typically signals problems with the ballast, so you should have it inspected if you notice changes in the color output of the fixtures. For example, metal halide lamps tend to appear green when the capacitor in their ballast is deficient.
- Frequent lamp failures – Lamps have a finite lifespan, but it is typically around 10,000 hours for MH and CFL lamps and around 20,000 hours for fluorescent lamps. If your bulbs burn out frequently, it could mean you have power supply issues, and if this happens frequently in a specific light fixture, the ballast is likely damaged.
Regardless of the problems with your lighting system, the best approach is to let a professional fix the problem. Sometimes many factors interact with each other and the relationship between them may not be evident.
Updating lighting installations
Of course, you can also contact professionals if you want to upgrade your lighting system. In general, there are three types of improvements you can make:
- Reducing energy consumption, which saves money by reducing energy bills.
- Improve optical distribution and lighting quality.
- Making lighting smarter with sensors and automatic controls.
Of course, there are cases where all three updates can be performed at once. Suppose you have an installation with first-generation fluorescent lamps that are manually changed and directly visible. If this installation is upgraded with integrated LED troffers controlled by occupancy sensors, all available benefits can be achieved simultaneously:
- Saving money: Using LED fixtures reduces input power and using occupancy sensors reduces the total time lights are on. For example, if you use lighting fixtures that consume 50% less energy and reduce their hours of use to 80% with automation, your energy consumption will only be 40% of what the original installation required.
- Elimination of glare: Exposed fluorescent tubes are replaced by troffers that optimize lighting distribution. This makes indoor environments more attractive and increases concentration.
In short, you should contact a professional or engineering firm whenever you have lighting problems or if you want to identify areas of opportunity to improve your current system. LED upgrades in New York City are typically eligible for rebates – make sure you don't miss out on these cash incentives.
2) Commercial HVAC Systems
Heating, ventilation and air conditioning installations are among the largest and most complex systems in commercial buildings. Its main objective is to maintain temperature and humidity within a comfortable range for humans, while constantly renewing the air inside the building; therefore, malfunctioning HVAC systems not only causes discomfort, but also degrades indoor air quality and can lead to health problems. If any of the following conditions are encountered in a commercial building, it is recommended that you contact an HVAC engineer or consulting firm:
- Inadequate internal temperature.
- Inadequate or fluctuating water temperature, in the case of water heating systems.
- Excessive humidity or dryness: Both conditions are detrimental to comfort and health. Moisture also leads to mold formation, which degrades indoor air quality.
- Drafty environment: typically caused by inadequate sizing of ducts or fans, or a combination of both.
- Noisy ducts: This condition often goes hand in hand with drafts and tends to have the same causes.
- Unpleasant/combustion smells: Unpleasant smells usually indicate that the ventilation system is not working properly; for example, negative pressure can attract odors from service areas or outside. If there is an odor of combustion gases, immediate attention is required, even if there is no visible smoke – combustion gases can be lethal in enclosed spaces.
Updating HVAC Installations
There are a wide range of potential upgrades that can be performed on a commercial HVAC system, but this can also cause confusion. However, you can determine what works best for your building with consulting services. The following are some common options:
- Upgrading specific equipment: There are upgrades available for almost all HVAC equipment. For example, a chiller and its cooling tower can be upgraded to more modern versions with variable speed control, greater efficiency and automation features.
- Automation and control: There are times when existing equipment offers high performance, but the full potential is not being realized due to improper operation. In these cases, sensors and control devices can be added/updated, optimizing the HVAC installation in real time.
- System-level upgrades: Sometimes the entire HVAC installation uses outdated technology, and performance can be dramatically increased by upgrading the entire system. The main disadvantage of this approach is that it can be very expensive; however, if a major renovation is taking place soon, it is a great opportunity for an HVAC system upgrade. An example of a system-level HVAC upgrade would be replacing an older four-pipe installation with a variable refrigerant flow (VRF) system or water source heat pump.
HVAC is typically the largest energy expense in a commercial building, sometimes exceeding all other energy expenses combined. Consequently, upgrades that improve HVAC performance tend to be very attractive from a financial perspective.
3) Pumping systems
High-rise commercial buildings typically use a pumping system because water from the local utility cannot reach the higher levels at the pressure at which it is supplied. Pumps are also necessary for fire sprinkler systems and any HVAC configuration where water is used to transport heat.
There are two main conditions that can seriously damage pumping system components: water hammer and cavitation. If left unchecked, the useful life of the equipment is drastically reduced.
- Water hammer or hydraulic shock occurs when the water flow is forced to change direction or stop suddenly, causing pressure peaks that spread throughout the installation, potentially damaging the equipment. Water hammer can be detected by the noise it produces and valve failures can become frequent. It is possible to mitigate water hammer with damping measures, such as pressure relief tanks, or by controlling the starts and stops of pumps so that there are no sudden variations in flow.
- Cavitation occurs when water pressure becomes low enough that bubbles form in the flow. These bubbles produce localized shock waves as they collapse and can potentially damage equipment. Pump impellers are particularly vulnerable to cavitation, as their blades cause a localized pressure drop as water accelerates around their edges.
If pumping system components frequently fail in a commercial building, these two factors are often the cause; the installation must be evaluated by a qualified professional.
Improving pumping system performance
As with lighting and HVAC installations, there are many energy saving opportunities in pumping systems. The following are some commonly suggested measures:
- Motor Upgrades: Because pumps typically run extended hours, upgrading to a high-efficiency motor can yield an attractive return on investment.
- Pump Speed Control: Pumping expenses can be reduced considerably if flow is modulated with a variable speed drive instead of valves.
Although pumps generally consume less energy than HVAC systems, their contribution to total energy expenditure is nevertheless significant. Additionally, consider that pumping and HVAC systems often work together, for example in AC systems that use water-cooled chillers or water source heat pumps. The two systems can achieve synergy if they are updated simultaneously.
4) General Improvements to the Building
When a commercial building has excessive energy expenditure, upgrades to individual systems can help significantly, but to achieve the best result it is also necessary to upgrade the building itself. There are three main areas of opportunity that an engineering professional or firm can help you with.
Building envelope updates
The building envelope must fulfill three main functions:
- Provide air tightness so that the only air that enters and leaves the building is the air pumped through the ventilation system.
- Providing a thermal barrier between the building and its surroundings, keeping heat inside during winter and outside during summer.
- Allowing sunlight to enter the building, but also minimizing heat gain due to solar radiation.
Building envelope upgrades aim to improve performance in these three areas, but they can be very expensive. However, the net cost is significantly reduced when these measures are implemented during initial construction or during a major renovation.
Renewable energy
Because energy is expensive in New York City, on-site generation with renewable energy systems can be an attractive option. The technologies with the greatest potential in commercial buildings are the following:
- Photovoltaic solar arrays
- Solar water heaters
- Fuel cell systems
- Geothermal heat pumps
- Small-Scale Wind Turbines
- Biomass heating
Solar energy may not seem attractive at first glance in New York, as the state is not the sunniest. However, there are so many tax incentives that compensate for the lack of sunlight. Combined with high electricity rates, this makes solar energy a solid investment.
Building management systems
Energy-efficient appliances reduce overall energy consumption, while renewable energy systems allow buildings to generate energy on-site. This can be complemented with building management systems (BMS), which can manage energy so that it is consumed when the cost is lowest, without causing discomfort or inconvenience to occupants.
- Utility companies charge higher rates when the grid is experiencing peak demand, but a BMS can monitor this situation and shift energy consumption away from those times. This saves money even if total consumption remains the same.
- Commercial energy consumers are charged for individual peaks in demand, regardless of whether they occur. A BMS can also mitigate or eliminate these spikes.
- A BMS can decide how best to use the output from renewable energy systems: Should it be sold to the utility, consumed immediately or stored for later use?
Final Observations
Commercial buildings can significantly improve their performance with an assessment carried out by qualified engineers. It is possible to detect and correct problems affecting existing installations, while finding areas of opportunity to save energy or improve comfort. The best results are achieved when building systems are addressed simultaneously, as it is possible to detect interactions between them, as well as opportunities for synergy.
