Building owners should follow this rock-solid plan when evaluating their HVAC systems
As a building owner, one of the bigger decisions you will face involves how to address issues with your HVAC system. Should you repair it or replace it?
You may be tempted at first to replace the system with something newer, shinier, and more efficient. People do it every day in other areas of their lives – mobile phones, clothes, appliances, vehicles, homes – but is that really the right move? Maybe, maybe not.
While you can’t gaze into a crystal ball and predict the future, if you want to make an informed decision based upon the facts, conduct a thorough evaluation of your HVAC system.
In this post, we’ll identify the reasons for repairing or replacing a system. We also will examine how to conduct a system evaluation properly and how to evaluate the data to make an informed decision.
The Reasons Why
Building owners replace HVAC systems for many reasons, including occupant comfort complaints, high maintenance costs, increased energy use, criticisms from maintenance staff, or a combination of these issues. All are valid reasons.
Before jumping into a replacement project to correct these issues, however, building owners first should identify the real issues with their system, what is causing the issues, and how to correct them. Why? Because it’s entirely possible to replace a system and yet the problem persists.
For example, if occupants frequently complain about being too hot or too cold, any number of issues might be the cause. A damper may be stuck open or closed. Perhaps a contractor failed to commission a building automation system properly. Or a VAV (variable air volume) box has never operated as designed. These issues can be corrected without too much effort and cost and do not warrant a system replacement.
Alternately, a centrifugal chiller’s tubes may be so worn from years of use and pipes corroded from neglect that repairs don’t make financial sense. In this case, replacing the system with a newer, more efficient unit and adding water treatment to your program may be the best move, which may pay for itself over time.
Another benefit of a system evaluation pertains to energy and environmental regulations. Since standards and regulations change constantly, your evaluation will reveal if your system remains in compliance. If it’s more than 10 years old, it may be outdated.
Keep in mind that a system evaluation differs from an energy audit. Energy audits analyze energy use, while an HVAC system evaluation looks at the bigger picture, with energy use being one piece of the puzzle.
Next, we’ll outline how to conduct a top-to-bottom system evaluation, the first step in addressing the specific issues in your building. Let’s begin!
First – and this is critical – remember that a successful evaluation relies on communication with those affected by the system. You must learn from building occupants if the system provides for their needs, whether that be process or comfort conditioning or both. And we don’t mean comments like “I’m too cold,” or “the unit is too noisy.” These comments can indicate problems with temperature, humidity and air movement in the building but don’t inform you about the system’s overall performance or people’s needs and expectations.
Begin by walking the building and speaking with the people inside. Remember that the HVAC system was installed for their comfort and to support their work. Ask occupants what they need from the system to support their activities. Learn if they operate equipment requiring unique temperature and humidity settings. Make note of when they work.
Next, visually inspect the system inside and out. Whatever plays a role in heating and cooling your building should be examined: units, ductwork, piping, pumps, cooling towers, diffusers, grills, and fans. Start with the intake grill where outdoor air enters the building. Look for contaminants that could enter your building’s air stream. Remove any built up debris, ensure the damper control has not been disconnected and examine the ductwork for damages.
Now move on to the air handler. Look for corrosion on the unit or water dripping from its frame. Examine the filters for sturdiness, cleanliness and proper installation. Check to see if control linkages have been altered (this often happens when someone attempts to temporarily fix a problem, which frequently becomes permanent).
Now, follow the ductwork throughout the building. Look for any damages that may leak or restrict airflow, and listen for unusual noises. Once you’ve covered one system, move on to the next. When you have visually inspected all the systems, you next will take performance measurements.
HVAC systems generally distribute a combination of both indoor air and fresh outside air. This minimizes the potential for outside contaminants to enter the building’s airstream and sustains acceptable carbon dioxide levels. Measure the flow of air in the supply and return ductwork and diffusers, which will inform you if the system has been moving air properly throughout the building. Too much or too little air movement can negatively impact system performance and occupant comfort.
Finally, measure temperature and humidity levels in the building, and compare the data to your controls system’s setpoints. Do they match? If not, discover why they don’t, which could be tied to thermostat location or airflow issues.
Throughout the inspection, write down what you see, and note anything out of the ordinary. Document what activities occur in the building – office work, medical, educational, processing, storage, etc. – and if the HVAC system meets the needs in the space. Note the building’s size, where equipment is located and the area in which it operates, climate, the types of fuel and energy powering the equipment and their cost.
Next, consider the operations being conducted in the building and the needs of the occupants inside. What do the operations need to function at a high level? Are the occupants comfortable? Compare the data from your evaluation with operations and occupant comfort. Do they align?
Congratulations, you’ve completed a thorough evaluation of your HVAC system!
You’ve identified issues in your building, interviewed building occupants, evaluated your HVAC system(s) visually, taken airflow measurements, and compared your findings with your building’s purpose. Now you are ready to determine if repairing or replacing your system makes sense.
Evaluate the Evaluation
First, compare the cost of repairs against the cost of replacing the system. You can get these numbers by contacting a professional HVAC systems provider or mechanical engineering firm. Some additional points to consider include the downtime for system replacement versus repairs, project funding, and any changes or additions that may occur to the building in the future.
Now, analyze the numbers. Again, consider seeking the professional opinion of an HVAC system expert. These people are trained to help you understand the data and give you sound advice. Whatever you choose, you now have subjective data to justify your decision.
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Many building owners encounter HVAC issues at some point in their facilities. You can address these problems by either repairing or replacing your system. It may seem like a daunting decision at first, but it doesn’t need to be.
By following the steps outlined above, you will have enough data to make an informed decision, one that will be the best for your building and the people inside. Additionally, seek the guidance of an HVAC professional if you need help throughout the entire process.
How is the health of your building? Does your HVAC system operate as it was designed? Do you receive comfort complaints?
For more information, please email Jonathon Goering by clicking here or call 316-265-9655.
Knipp Services works with commercial and industrial building owners to identify solutions to reduce downtime and increase building efficiency. We provide services that enable building owners to have a high-performance building. “Making Buildings Better” sums up the mission statement of Knipp Services.