6 Commercial HVAC Best Practices You Need To Know

Looking Up at Hong Kong SkyscrapersThe installation and maintenance of HVAC systems in commercial buildings has traditionally been implemented with a focus on building code compliance, statutory requirements for health & safety and providing comfortable conditions for building occupants and visitors. Oftentimes, due to timing pressures and cost constraints, inferior equipment and maintenance agreements are put into place, with little consideration given to the long-term effects on efficiencies, property value and the fluctuating environmental effects on comfort level. When energy efficiency gains are neglected and life cycle costs are not taken into consideration, consequences of higher energy and maintenance spend are not addressed.

In addition to substandard equipment and maintenance agreements, fewer than half of companies perform preventive or predictive maintenance on their building HVAC systems. What property owners and facility managers need to consider, is that studies have shown that good maintenance can cut HVAC energy costs while also extending equipment life, improving occupant comfort, and increasing uptime. Effective maintenance can reduce HVAC energy costs by 5 to 40 percent depending on the system or equipment involved. Proper maintenance is just one important factor for commercial HVAC systems – here are 6 other best practices you need to know:

  1. Controlling your control system is an integral part of any HVAC system maintenance.

The control system on your HVAC system has a specific purpose and can be as simple as an electronic programmable thermostat or as complex as a robust automation system. Regardless of your system’s level of sophistication, the controls should be used to best optimize the overall HVAC system. Additionally, your controls offer the best opportunity to eliminate energy waste and avoid comfort issues. Working with an efficiency expert can help you substantially decrease energy costs over the lifespan of your equipment.

  1. Simultaneous heating and cooling occurs in many systems. If it can’t be eliminated, it can be minimized:

Simultaneous heating and cooling can increase operational costs. When the central system delivers cooler air than required, the zone reheat coils must temper the air before it is delivered to the space. At this point the heating and cooling system may be working against each other. This creates additional wear on equipment.

Chillers and boilers may run when none are needed, or a larger chiller or boiler may be sequenced on when a smaller one could have met the load. Electric reheat coils are turned on when they could have been left off. Variable-flow chilled-water and hot-water systems operate at higher flow rates than necessary. Equipment capacity is reduced because the heating and cooling systems are working against each other. This can lead to under-heated or under-cooled areas, discomfort for visitors, and maintenance costs that are sure to be affected.

  1. Monitoring and improving fan speed controls

Most conventional building HVAC systems are designed to operate fans and pumps at a constant speed. Building needs, however, are anything but constant. In a conventional system, some form of mechanical throttling can be used to reduce water or air flow in the system. While mechanical throttling can provide a good level of control, it is not very efficient. A variable frequency drive (VDF) offers an effective and efficient alternative.

Facility managers and maintenance professionals understand that one of the most successful energy management tools applied to building HVAC systems is the VDF. VFDs are installed on fan and pump motors in a range of variable load applications. When in place, typical energy savings vary from 35 to 50 percent over conventional constant speed applications, resulting in a return on investment in approximately six months to two years.

  1. Night setback and scheduling

When building systems are properly controlled during unoccupied times, significant cost reductions in commercial buildings can be achieved. Night, weekend and off-hour setback and scheduling is easy to implement, and simple to track and administer. The goal is to shut off systems whenever possible or whenever they are not needed, and refrain from starting up the system for minimal or occasional use. Many times, night-time operations can be the most costly, if roughly only a small percentage of staff are working and all heating, ventilating, and air conditioning equipment is running. A few basic tactics to remember include

-Turn things off when not in use

-Change room set points when spaces are unoccupied

-Close outdoor air dampers when the building is unoccupied

-Disable chillers and cooling equipment during unoccupied hours if possible

  1. Use Energy (EUI) and Benchmarking

A closer look at a building’s past energy performance and energy-use pattern, and comparing it to typical similar buildings energy use can further identify problem areas.

The energy-use index (EUI) is the amount of energy used by a building per square foot of building floor area. By normalizing energy use to floor area, buildings can be benchmarked and compared for relative energy performance. An EUI can be based on whole-building energy use or on specific end uses such as lighting or heating. A whole-building EUI is a good measure of overall energy-savings potential. While your HVAC contractor or facilities manager is likely your best resource, other tools are available to help with calculating EUI.

  1. Operation and maintenance:

A few other operation and maintenance tips to consider as best practices for your property(s) include:

– Tighten belts or switch to notched belts

– Regularly test refrigerant charge to ensure optimum conditions

– Clean outdoor coils (condenser) by using a pressure sprayer. Be careful not to damage/bend aluminum fins

– Keep filters clean for sufficient air flow and heat transfer. Clean filters require less fan energy to deliver air

Establishing best practices and implementing regularly scheduled maintenance of HVAC systems can increase energy efficiency and longevity of equipment. Obtaining the right equipment for efficiency and researching what is best for your region and climate, is the best thing to do when choosing the best system or product. For the long-term and the overall comfort of your property, take action now to put practices into place for energy efficiencies and cost savings.

Keeping Cool While Keeping Costs Down

1_2015The following article written by Brock Studinski, VP of Energy & Technical Services at Evergreen Air Conditioning, was recently published in the January / February issue of Professional Retail Store Maintenance.

It’s nothing new for FM professionals to find themselves confronted with questions regarding how to reduce spending or cut costs. However, many facilities managers increasingly find they are also being challenged to be “green” or save energy.

Some FMs may be overwhelmed when it comes to discussing the nuances of HVAC, but it really boils down to two basic principles: First, how to effectively transfer heat from inside your store to the outside and second, how to distribute that now cooled air to the space. Here are five quick tips to make sure your HVAC system runs more efficiently.

  1. Belts – Consider using notched or cog-style belts. Studies by the Department of Energy show that notched belts allow for less slippage and generate less heat, prolonging the life of the belt. A notched belt for a 20-ton unit may cost $6 – $9 more than a traditional “V” belt, but it will save nearly $40 in electrical costs. Now compound that by thousands of HVAC units, and you will see tens, if not hundreds or thousands of dollars in savings annually. The link to a free calculator can be found here.
  2. Filters – Link (ring) or pleated? What MERV rating is preferable? How many changes are required per year? These are just a few of the questions you need to answer when selecting filters. Unfortunately, there are no easy answers to most of those questions, as it really comes down to the application. Everyone will agree, however, that is a very important to make sure the incoming air is completely filtered in order to protect the evaporator coil. If you select a filter that is too restrictive, you force your fan to work harder to overcome the added pressure drop. However, if you choose a filter with too little capacity, you risk fouling your coils and causing your refrigeration system to work overtime.
  3. Coils – Keeping your refrigerant coils clean is key to ensuring that your system can effectively condition your store, prolonging the life of the system and keeping your utility costs down. Moderately fouled coils can increase electrical costs by as much as 30 percent. If you are unable to transfer enough heat to the airstream, you also risk frosting or freezing the coil.
  4. Refrigerant – If there is not enough refrigerant in the system, you risk not being able to fill the coils and, as a result, impeding heat transfer. On the other hand, if you have a system that is overcharged, the refrigerant will have a difficult time changing state and transferring heat. Think of your air conditioning system like baking bread: If the oven is too cool, your bread will not set; if it is too hot, you burn it.
  5. Condenser fans – As manufacturers strive to increase the efficiency of their products, it’s more important than ever to keep all of the components working. The condenser fans are often overlooked because, in most cases, there are multiple fans on each unit. But just as indoor (evaporator) fans are important in transferring heat to cool the space, condenser fans complete the cycle by transferring that heat outside. If the fans are not operational, you run the risk of increasing refrigerant pressures and not being able to adequately cool the space, not to mention shortening the life of the other components.

View this article as it appeared in Professional Retail Store Maintenance magazine.

5 Winter Energy Efficiency & Maintenance Tips For Commercial HVAC Systems

Thermometer

Winter months are upon us and it is this time of year that HVAC maintenance for commercial and multi-site systems require critical attention. There are a few important considerations that should be at the forefront of any property owner and operations manager’s maintenance plan to ensure the equipment investment is protected and employees and customers are provided with a comfortable environment.

While winterizing HVAC systems for commercial buildings or multi-site properties can be a demanding task, a thorough inspection and series of check-points are essential for reducing unnecessary future maintenance and expenses. Additionally, energy efficiencies occur when units are serviced at a high level. Here are five key considerations when implementing facilities’ winter HVAC and energy plans:

  1. Create a preventive maintenance schedule.

Establishing a commercial HVAC maintenance agreement with expert professionals is a great way to keep your system running at peak efficiency. Not only will an agreement ensure that seasonal checkups are done on schedule, but having an HVAC maintenance agreement means you will receive priority service in the event of equipment failure or other problems. Identifying issues early in the season will prevent problems from happening at the worst possible time, such as the coldest day of the year. Planning ahead also helps expedite the process of acquiring parts while avoiding increased expenses over time.

Studies have shown that routine maintenance is a key driver in energy efficiency for commercial HVAC systems. Working with a service contractor that understands the history of each of your facilities and the energy challenges faced – will not only keep you’re your units running efficiently, but reliably longer. Having an established winter season maintenance plan is an essential component of your HVAC operations to ensure equipment is working properly and energy efficiencies are identified.

  1. Calibrate thermostats, determine the best settings for your property and stick to a monitored plan.

As cold winter months approach, have a professional commercial HVAC technician calibrate all the thermostats in your commercial property. If thermostats are too far off from each other, systems will not be as efficient as they could be or worse, simultaneous heating and cooling could occur.

  1. Leaks and equipment failures should be fixed.

Building owners and operations directors, in particular, should always work with their HVAC consultant to identify ways to make facilities more safe and efficient. Heating is likely the largest end use of fuel in commercial buildings, and an obvious place to look for safety hazards and energy savings. It is essential to make sure there are no holes in the heat exchanger and all tubes and orifices are free of debris.

During the winter months, equipment should be checked and cleaned or replaced; otherwise may be faced with the risk of harmful gases like carbon monoxide getting released into the indoor air due to imperfect burning.

  1. Ensure economizers are operating properly.

It is likely your HVAC system is equipped with an economizer – a component that allows the unit to use outdoor air for cooling, provided the ambient air is below a certain temperature and the humidity is below a certain percentage. This type of cooling is often referred to as “free cooling” because it cools the building without the use of energy required to run a compressor. It is extremely important to work with your HVAC specialist to ensure that your economizer is operating properly.

If the economizer dampers are stuck closed, you will not be able to take advantage of free cooling. If the damper fails to close, frigid air would be brought in and heated – resulted in wasted energy and an uncomfortable environment.

  1. Check filters and replace as needed.

The purpose of air filters is to catch dust and other particles that pass through the air. Air quality directly affects the condition of air filters, while dirty filters can restrict airflow and hamper the efficiency of your entire HVAC system. Consider changing air filters 3-4 times/yr. Higher quality filters can save you on maintenance and replacement costs in the long run, as well as offer an improved level of indoor air quality.

There are many considerations to control energy costs and keep equipment operating during the winter months. It is important to work closely with your HVAC service provider to identify potential problems and perform maintenance before costly breakdowns occur. Typical service agreements cover rooftop units, chillers, boilers, compressors, air handlers, cooling towers, pumps, variable speed drives, controls and accessories. Be sure a preventive maintenance plan is tailored to meet the unique needs of your commercial facilities to provide the most comfortable and safe environment for guests during the winter months.

What commercial and muti-site HVAC challenges do you face this winter?

Learn about the experienced consultation and service provided by the HVAC experts at Evergreen Air Conditioning.