Frequently Asked Questions
HVAC Expertise For Commercial Building Owners/Operators
A: Fans draw air in through grilles called returns and force air through ducts and into the conditioned space through supply registers.
A: The majority of ducts are constructed of metal and installed by tradesmen called sheet metal workers. However, cloth and fiberglass are sometimes used, as well as “hollow” spaces within the building – the space above a drop-down ceiling is often used as the return, for example.
A: Each material has characteristics that may favor its use in specialized applications. Sheet metal has a number of advantages: It is made from recycled materials; it is non-combustible; it is the sturdiest material; and it is the easiest to clean. That’s why sheet metal continues with its historical position in HVAC systems as the material of choice.
In fact, sheet metal use in HVAC is greater than all other materials combined. The steel and aluminum used for ductwork is a “high achiever” in the 21st-century move toward sustainable buildings because of the high recycling rates and cleanliness.
And, if a metal duct system is ever removed and replaced in a building renovation, the sheet metal duct you bought long ago will probably be recycled.
A: Ducts that are improperly constructed, sealed, or installed can leak excessive amounts of air, provide poor air distribution, and can also “pipe” noise around the building.
Additionally, ducts can become dirty if put into service before building construction is complete; there’s a lot of dust and dirt around most construction sites.
What’s more, ducts in older buildings can become dirty after years in service, especially if filters are not changed on a regular service basis.
Ducts play a key role in energy usage from both how much friction the fan “sees” as it moves air throughout the duct system to how well they distribute heating and cooling to keep occupants comfortable.
A: If you are building a new structure, make sure the HVAC system designer is specifying SMACNA’s prescriptive duct sealing standards.
Our companies and workers, who have trained in this industry and gained a vast amount of HVAC expertise, recommend prescriptive sealing of ductwork as one measure that will normally lead to the most cost-effective control of leakage without the need of expensive leakage testing.
Code-making bodies recognize construction standards developed by SMACNA, the leading authority on duct construction and installation.
A: This Web site is designed to help owners and facility managers find standards-conscious contractors that use well-trained and experienced workers. Find an Expert to find contractors with trained, skilled, and knowledgeable workers – Your source of HVAC Expertise.
You’ll gain peace-of-mind by using our roster, rather than simply picking a name from the yellow pages.
A: While that is possible, there is a range of possibilities. Initially, your best move is to hire an experienced HVAC service contractor to review your entire HVAC system. How can you identify firms in your area – or across the nation – with trained workers, savvy managers, and HVAC Expertise? By clicking on the Find an Expert.
Q: My company IS building new. We had a problem on a new building just last year. The drywall contractor told us to turn the HVAC on to help their work dry faster, which we did. After the building was put into use, one of our tenants happened to look in the ductwork and found a lot of debris. Obviously, she didn’t want to be breathing that, and it cost us a great deal of money to clean the ductwork. How can I avoid repeating that in the building I’m starting up now?
A: Our industry has a simple answer. Construction sites feature a lot of airborne dust and debris. If you turn on your permanent HVAC system in that environment, you WILL have a problem. So the answer is: Don’t turn it on; use temporary heating or cooling.
A: The smartest, most cost-effective long-term solution is the use of temporary heating equipment. Your HVAC system will remain clean and your tenants won’t spend move-in day screaming at you!
A: If not carefully designed, the system’s ductwork can act as large speaker tubes and transmit noise throughout the building. Interestingly, the direction of airflow has little effect on the sound transmission. Adequate noise control in a duct system can be achieved if the designer understands basic noise control principles.
If the building is in use, it’s too late for a design change. To reduce the noise, you’ll need a technician, with a high level of training, to troubleshoot your complaint. He or she must understand the very complex issue of sound and vibration principles and testing.
We urge you to use this site to find a find a local contractor by clicking the Find an Expert and selecting one that does testing and balancing.
A: Mold is a “whole building” issue with moisture, and the broad answer to your question is to keep all moisture out of your building, and control and contain moisture that is necessarily in the building.
Roofs can leak. Window flashings can leak. Pipes carrying water can leak. Anywhere you have water or excess moisture, you must control and contain it. An HVAC system’s ducts can become contaminated – but the root cause is invariably uncontrolled moisture, not the ducts. Of course, if moisture enters your building in excessive amounts and mold does grow, the ductwork can convey mold and excess moisture to other parts of the building.
But the solution isn’t replacing the ductwork or turning off the ventilation system. The answer is identifying how the moisture is getting into your building or out of control from in-the-building sources and correcting the problem. This is “moisture management.”
A: The SMACNA- SMWIA team has bypassed what some have viewed as a golden opportunity to make a bundle of money from a panicked public.
Your question’s answer is: No.
With hundreds of thousands of people with HVAC Expertise across the U.S. working at approximately 2,000 companies, we elected to avoid what perhaps you’ve seen in other industry segments.
Our contractors can help you diagnose problems with excessive moisture. They can help “fix” them by investigating your building’s problems. Again, as stated at SMACNA’s 2003 Convention, the bottom line for all of us is to keep moisture out of the building, and control, and contain what is necessarily in the building. If you do this well, you will condemn any mold in your building to an early death!
Without moisture, mold cannot thrive.
A: The three key elements that drive a building’s overall energy use are:
- The HVAC system—typically THE most important for commercial buildings,
- The building’s overall thermal envelope; and
- Large loads, computers, and lights in commercial buildings and industrial processes in industrial-type buildings.
System sizing: Most of the intersection between HVAC systems and energy use occurs in the design stage. If the system is improperly designed, this can lead to inefficiencies, which drive energy costs higher than they have to be—some, but not all of these design problems, can be addressed after the fact.
Building envelope leakage: Often, HVAC energy “waste” is actually driven by a thermally-inefficient building that is necessary to maintain reasonable comfort. Many commercial buildings in the U.S. are old. As of 1999, there were more than 900,000 commercial buildings that were built in 1945 or before!
In such cases, it’s not duct leakage that’s the problem – it’s building envelope leakage! Hot air flows in during summers; cold air in winters. Result: You pay more to create indoor conditions that are comfortable.
Older equipment: On the subject of older buildings, it is worthwhile to determine the age of your HVAC system. There have been numerous technological advances and federally-mandated energy efficiency increases for HVAC equipment. Even if your equipment was “state-of-the-art” at the time of installation—you might be suffering from technological disadvantages.
Older HVAC systems might provide heating and cooling, keep humidity reasonable, and move air around. Everyone inside the building might be comfortable most of the time! But you may be paying a lot more than you need to – every month – to do it!
Waste heat: Additionally, activities and equipment within your building introduce heat into the conditioned environment. Do you have a lot of operating equipment inside your walls? It’s likely that, no matter what it is—from a computer or photocopier to something more “industrial”—it is venting a certain amount of waste heat.
Even an office building lighting system generates heat! In summer conditions, that heat adds to the building’s cooling load.
Controls: Even with a state-of-the-art building envelope, a minimum of indoor waste heat, and recently updated HVAC equipment, you could be losing money due to system operational inefficiencies. HVAC Expertise contractors understand all the elements of a superior HVAC system and how to most effectively control the system.
Maintenance: Appropriately planned maintenance is the least-cost insurance a building owner can purchase. Regularly changed filters keep airflow at optimal levels, while protecting the duct and occupants from easily-caught dust and particles. Regular check ups of refrigerant levels, belt drive, etc. assure lowest operating cost and help to protect against expensive catastrophic failure of equipment and building HVAC system downtime.
Whether you’re building new or have an older building, the contractors you’ll find through this site CAN help you analyze options for boosting performance and minimizing costs.
A: We’d have to provide a separate Web site to include hundreds of pages to totally answer this question. The answer depends on issues like:
- Where are you located?
- How old is your system?
- What are your system’s control strategies?
- How much lighting and equipment is in the building?
- How old is the building?
. . . and that’s just a sampler. Our best advice is to choose a reputable contractor. After you get the name of one or more local HVAC Expertise contractors in your area, check references – we think you’ll find many satisfied building owners who are HVAC Expertise customers!