When Should My Building Be Balanced?

A proper air balance within a building is an important factor for providing a healthy and comfortable indoor environment for occupants.  Like many other critical building systems, the air balance must be maintained over time, and isn’t something that you can simply “set and forget”.  So then, when should a building be balanced?  Here are some common events that would trigger the need to perform an air balance.

New Construction:

Every building that has some form of HVAC system (heating, ventilation, and air conditioning) should be balanced when it is first constructed. By this, I mean that the HVAC systems should be inspected, tested, and adjusted to ensure that they are operating correctly, efficiently, and as intended by the design engineer and as expected by the building owner. A balanced building will provide a comfortable and healthy indoor environment for the occupants, delivered in an energy efficient manner, and will have a proper positive pressure. Select a TAB professional to perform the air balance who is objective, meaning that they are hired directly by the building owner and are independent of the installing contractors and equipment manufacturers, who is experienced in your particular type of building and HVAC systems, and who is certified by an industry-recognized accrediting agency, like NEBB or AABC.


The building should be rebalanced during any major remodel event, such as expanding the building or changing the functional use of a space within the building. This is important because the HVAC system was originally designed and balanced for specific use conditions, and when those conditions change, the system will need to be readjusted. Be sure to consult with your mechanical design engineer prior to the remodel to verify that the existing HVAC system can handle the new demands. The building should also be rebalanced anytime elements of the HVAC system are modified or replaced, such as when ductwork is rerouted or when aged equipment is upgraded. This is important for verifying that the new equipment is installed correctly, operates properly, and is adjusted for the design conditions. For a building that has cooking operations, it is important to also rebalance whenever the cooking appliances are relocated or replaced with equipment of different use or heat load, such as replacing an oven with a fryer. This is significant because a kitchen ventilation system is designed for a specific bank of appliances. When the appliances and cooking operations change, the ventilation system will need to be adjusted to ensure it correctly captures and contains the heat and effluent produced.

Periodic Tune-up:

Even if a building has been balanced during the original construction, and it is not undergoing any remodels or equipment replacements, it should still be rebalanced periodically. This is because the performance of the HVAC system can change over time due to normal use and wear and also due to adjustments made by operations and maintenance personnel. Examples of this are when an operator switches the fan mode of the thermostats from ON to AUTO or when a service technician closes the outside air dampers in a rooftop unit in an attempt to fix a comfort complaint. For the complete building HVAC system, I would recommend a proactive rebalance frequency of every two to three years. This will ensure that the systems operate effectively and efficiently throughout their lifecycle and will help prevent the very costly issues created by having a building out of balance for a prolonged period of time.

Want to understand more about air balances? Read about air balance basics for existing facilities, watch our video on how an air balance works, or contact us to learn more!

Is Your Business Haunted Or Is It Something Worse??

Has your business experienced…

Zombie Levels of Productivity

Poor levels of fresh outside air leading to insufficient IAQ can decrease air quality. According to a study done by Harvard University, productivity levels can be increased by up to 61% when the proper amount of air quality is introduced into the space, and can be increased by 100% when doubling the ventilation.

Chills Running Down Your Spine or Sweaty Palms?

Improper heating and cooling due to an unbalanced building means air is distributed unevenly which creates temperature variation. Hot and cold spots around your building are probably signs of an unbalanced building, or are they??

Something Strange in the Air?

Air drafts can be caused by too much air being delivered to certain areas and then the air moves between rooms in order to reach an equilibrium of pressure.

Musty Odor Means Something Is Lurking

When air isn’t cycled properly through the building on a regular basis and you let the humidity get too high, you provide a breeding ground for bacteria and mold. Considering the average adult spends 92% of their time indoors, that means a lot of time breathing in these gross pollutants!

Mysterious Noises No One Can Explain

Have you been startled by an abrupt sound somewhere in your building that you can’t pinpoint? Poorly sized belts or pulleys can cause RTUs to squeak as they are operating, and duct leakage has been known to create some creepy noises as well.

Doors Opening and Closing With No One There

Pressure differentials caused by an imbalance of air being delivered to certain rooms can make doors open and close on their own.

Don’t call Ghostbusters just yet! There is a good chance you building is not actually haunted but instead just needs a good balance. Many of the above culprits can be easily fixed, and will not only improve your building’s health, but the health and productivity of everyone inside (one study shows estimated productivity benefits from increased ventilation could be as high as $6,500 per person per year!).  Learn more on what a building balance is here or contact us for more information on how to get rid of the pesky (and creepy) issues you are having!

How to Read and Interpret a TAB Report

HVAC system testing, adjusting, and balancing (TAB) is one of the most misunderstood trades.  In spite of its 50-year history, many contractors believe to do TAB, technicians simply need to show up with a flow hood, read grilles, hand over a piece of paper, and ask to be paid thousands of dollars. There happens to be a bit more to it than that.

Among the complexities of the trade, the final TAB report is perhaps the most critical and most misunderstood.  When the painters are done, the walls change color. When electricians are done, the
lights come on.  When the HVAC technicians are done, the building heats and cools.  When the TAB professional is done, he or she simply hands over paperwork and the other trades and owners simply must take their word for it. That paperwork is the TAB firm’s final product and should be professional, complete, concise, and as useful as possible for the end user.

Whether that end user is a design professional, facilities manager, property owner, municipal inspector, or other concerned party, the TAB report should be written and compiled in such a way that even a layman can identify any issues that potentially impact building performance.

There are five elements that any should be consistent in any TAB report:

  1.  Overall professionalism
  2.  Certification
  3.  Remarks and deficiencies
  4.  Discrepancies between design values and actual data
  5.  Mechanical drawings and floor plans

Overall professionalism speaks for itself.  Are the numbers hand-scrawled on a piece of paper or is the TAB report well-presented and organized? Does it appear to be a document reflecting the skills and expertise of the industry veteran who produced it?  Basic elements that should be included in a professional report include: an executive summary / general remarks, distribution list, table of contents, symbols and abbreviations, as well as corresponding mechanical drawings and certification.

In today’s litigious society, I’ve had more than half a dozen of my TAB reports subpoenaed in legal proceedings.  Every TAB report I compile is issued with the mindset that it may end up in the hands of a jury selected from a variety of backgrounds and be examined by professional witnesses who will scrutinize it’s
content. Once that standard is achieved, the report should be able to be tell the overall story in a way that virtually ANYONE can understand, regardless of background.

Certification is a critical element of any TAB report.  Sure, there are many incredibly capable technicians out there who operate without certification.  However, certification ensures that the
professionals who compiled the report are vetted, tested, and properly equipped to perform the work.  Certification also ensures that the TAB firm and TAB professional are current to their certifying
organizations’ standards.  Finally, certification provides recourse to the end user should there be issues with the TAB report or work performed by the TAB contractors.

Remarks and deficiencies are very often overlooked.  The professional TAB report should have both an executive summary / general remarks section up front to explain overall conditions and issues. If applicable, the summary should be followed by an itemized list of items that remain to be corrected.  There is a growing trend to include pictures of deficiencies as well. Often such deficiencies are corrected during the course of the test and balance work and by the time the final TAB report is issued, there are no remaining issues.  If that is the case, there should still be general remarks explaining the scope of work and conditions at times of testing.

Discrepancies between design values and actual data collected. The actual test data can be confusing and tedious.  Especially reports containing hundreds of pages of numbers and readings.  Even to the well-trained eye, reviewing a TAB report can be like trying to read the streaming code in the Matrix movies.  However, anyone can read “percentage of design” and determine that any item not within +/- 10% or (5% in some cases) needs further review.  ANY item not within design tolerances should be accompanied by a remark explaining why.  The remarks should also explain what corrective action can be taken, or if a corrective action is even needed.  Again, this can be a critical part of the report that should be written to stand out, even to the layman, without being overly technical or confusing.

Finally, let’s talk about mechanical drawings and floor plans. I have the great fortune of providing training to professionals from all over the world. These professionals come from a wide variety of backgrounds.  The number one complaint I hear from design professionals and facilities managers is that many TAB reports are missing floor plans / mechanical drawings that correspond to the reported data.  This is the number one item in any TAB report that makes the report practical and functional to the end user.

There are many instances where plans are not provided to the TAB contractor, or cannot be removed from a facility.  There are many options around these situations.  From a simple, hand-drawn
ceiling plan indicating supply, return, and exhaust diffusers, to taking a picture of the immovable plans and numbering the inlets, outlets, and equipment. You can use a CAD program, or even something as simple as PowerPoint to provide a visual reference. Regardless of how this is accomplished, these numbered plans and/or drawings are the glue that bind the TAB report together, and MUST be included.

The TAB report is a critical element of the construction process that assures the design team’s intent was met. It also assures the building owner that they have the systems they paid for.

The TAB report should reflect the professionalism and skills of the technicians who provided the work behind it and who ultimately compiled and published it.  However, it is a meaningless collection of data if it is not reviewed, understood, and used.

Using An Air Balance Report for HVAC Upkeep

There is much hype these days in the facilities management industry about the importance of preventative maintenance, especially for critically important HVAC systems. In our experience,  we are often urgently called out to a facility because the site’s HVAC hasn’t been well maintained. While we’re happy to help, we also want to share insights so you don’t have preventable crises.

In a recent FER magazine article Realizing ROI on Planned Maintenance – author Michael Sherer quotes David Pogach, LEED GA, Longhorn Steakhouse Facilities Manager, as saying:

“We look at planned maintenance as a way of making sure equipment lasts its expected life cycle. … We know these programs work. They save money, so for us it’s not a debate of whether to spend the money now or later. We maintain our equipment.

“Planned maintenance makes the most sense for equipment that in-house staff doesn’t have the expertise or time to maintain. Most operators who have programs in place start with HVAC because putting people on the roof is a liability issue, and most foodservice employees don’t have the expertise to service HVAC systems.”

Following are ways you can use your air balance report to help start a new preventative maintenance program or audit the effectiveness of an existing one:

1)    In your report, you’ll have a list of deficiencies and recommendations for optimal operation (figure 1). First and foremost, you should schedule completion of these tasks as part of your quarterly or semi-annual preventative maintenance program.


2)   Another great use of a test and balance report is using the unit inspection checklists to see what should be monitored by your HVAC contractor (figure 2).

figure 2
Rooftop inspection checklist


3)   The report will also include unit3)  A third way to make the most of your air balance report is to use the HVAC system layout drawings to locate and inventory all equipment that needs to be maintained (figure 3). Please note that not all test and balance contractors provide this. manufacturers, model numbers, serial numbers, pulley sizes, belts sizes, motor horsepower ratings, and a large amount of other useful data which would aid in the implementation or upkeep of any preventative maintenance program.

figure 3
Building and rooftop layout

 4)   Finally, make sure your preventative maintenance programs include all of the items below. Omitting regular service on these is a leading causes of problem stores.

  • Change belts when damaged and verify proper belt tension
  • Replace filters quarterly
  • Clean outside air filters
  • Clean kitchen hood filters
  • Clean fan blower wheels
  • Clean grease traps
  • Clean evaporator and condenser coils
  • Verify thermostat settings are correct and someone onsite is trained how to adjust programming

Additional Reading

1. Realizing ROI On Planned Maintenance, Foodservice Equipment Reports Magazine, Michael Sherer, Aug 3, 2015

2. How To Read A T&B Report,  Fresh Air Blog, Derick Ramos, Aug 27, 2015

3. Planned HVAC Maintenance Adds Up to Big Savings for Retailers, Energy Manager Today, Karen Henry, May 11, 2015

How To Read A Melink T&B Report

Understanding HVAC test and balance reports can be a challenge, especially for busy facility managers. Knowing you have limited time and likely several facilities to oversee, we’ve put together this simple guide to help you navigate your Melink T&B reports.  If you don’t have your T&B report on hand, see our Melink T&B page for a sample report by clicking here, navigate to the “Stay Informed” section.


Melink T&B Certified Test Adjust Balance Report
1.  Review the report’s Cover page carefully. Be sure the information is accurate, including the facility’s location, store number if applicable and original visit date. This is vitally important if you have multiple facilities. While you’re in review mode, confirm the names, phone and fax numbers, and email addresses on the Test And Balance Contact Information page.
Field Summary Corrections ABCD Restaurant 2.  Concentrate on the Field Summary: Corrections pages. This section basically is the written story of what Melink’s T&B technician(s) did at your facility during the site visit. It gives a breakdown of who the technician talked with, what kind of equipment was used for the testing and balancing, inspections and adjustments that were made, and any other important actions and observations.
Field Summary Corrections ABCD Restaurant 3.   Consider the Field Summary: Punch List your action steps section of the report. The Punch List details the remaining deficiencies of your facility’s HVAC/mechanical systems, along with instructions for corrections. (Please remember the corrections are necessary to comply with design specifications.)

At the bottom of each Punch List page is a box that states: “Melink recommends revisiting this store due to the deficiencies listed above.” It then gives choices of Revisit necessary? 30-60 days after opening? Before opening? Do not overlook the recommendations listed here.

Field Summary Recommendations ABCD Restaurant 4.   Read Field Summary: Recommendations to learn what steps your Melink technician recommends you take to improve comfort and energy efficiency. The items listed here are not requirements of the design specifications.
ABCD Restaurant Photos 5.   Understand that the Photos section is simply a photo gallery that correlates with the Field Summary: Punch List. The photos are listed in order of importance, with the highest-level deficiencies listed first. The Photos section also cites best practices and gives credit where it is due.
Rooftop Inspection ABCD Restaurant 6.  The Rooftop Inspection,Above Ceiling Inspectionand Below Ceiling Inspection sections give you a quick way to see all the checklist items. The √ indicates the action was completed; an X indicates a deficiency (this is noted in the Punch List section too); and N/A means Not Applicable.
Building Air Balance ABCD Restaurant 7.   Detailed readings in the Building Air Balance, Motor Load Summary, Rooftop Units Data, Air Distribution Data, Exhaust Fan Data, Kitchen Hood Data andThermostat Settings sections are available for those interested in digging deeper. Most important are the Field Summary: Corrections, Field Summary: Punch List, Field Summary: Recommendations and the Melink recommendation box located at the bottom of each Punch List page.
Building and Rooftop Layout ABCD Restaurant 8.  And lastly, the Building and Rooftop Layout section on the final pages of the T&B report is a key that shows where your building’s HVAC-related equipment is located. Each piece of equipment is assigned a numbered code that corresponds to review sections of the report. (The Abbreviations page near the top of the report also is a helpful way to learn names of the equipment noted on these pages.)

“We want facility managers to understand how important it is to follow through on the Punch List items then have us back for a final visit, if necessary, to verify the work was completed properly,” says Derick Ramos, regional network manager of Melink’s T&B business unit. “A lot of times, facility managers don’t know if the fixes were made as instructed, so a re-visit is critically important. Our overriding goal is making sure the building is working properly for the owner.”

Troubleshooting Air Balance With Mechanical Contractors

Are you still experiencing HVAC comfort or efficiency problems?  It’s time for the next level of technical HVAC skill.  Though at this point you may have realized you’re dealing with negative building pressure, you might wait on calling the air balance contractor and first become more informed about the problem with your management team.  It’s time to call in your trusted mechanical contractor (MC).

Your contractor’s first steps will be to inspect many of the same areas we advised in our previous post. These areas should include circuit breakers, thermostats, as well as the areas listed below.  In addition, you should locate any past air balance reports and confirm that all the punch list items were corrected.  With these observations and baseline data as your starting point, you or your MC can begin to formulate a hypothesis. To dig deeper into problems, check the following areas where we most frequently find the causes of HVAC comfort issues:

1.   Filters inside the unit

Dirty, old, or clogged filters will restrict airflow through the unit.  Filters should be at least replaced quarterly for a commercial unit and can be added as part of a preventative maintenance scope of work.  In the Restaurant Facility Management Association’s Facilitator Magazine, Red Lobster Facility Manager Angela Hughes writes in her article Staying On Top of Comfort Concerns, “The washable metal filters inside each makeup air fan need to be cleaned during major preventative maintenance.  These are often overlooked by HVAC preventative maintenance vendors.  Dirty filters can block airflow into the unit and greatly affect the building balance.  If the filters are damaged or missing, be sure to replace them.”

Dirty air filters

Above: Dirty Outdoor Filters


2.  Inspect coils inside units

Dirty, clogged, or frozen coils can also heavily restrict airflow through the unit. Mechanical contractors are equipped to unfreeze and clean coils.  Angela Hughes explains, “Dirty coils will cause the unit to freeze up and temporarily shut down, which causes stress on the compressors.”  Further, if the rooftop unit (RTU) blower compartment and/or coils are dirty, then they are likely causing reduced airflow and contaminated air.  The solution is to clean internal components of the RTU.

Frozen evaporator coil

Above: Frozen Evaporator Coil

Dirty RTU blower compartment

Above: Dirty Rooftop Unit Blower Compartment

RTU dirty coil

Above: Dirty blower wheel inside Rooftop Unit

3.   Check refrigerant levels

Low refrigerant levels can lead to uncomfortably warm temperatures. Your mechanical contractor should be equipped to refill refrigerant.


4.   Open up units and inspect outside air dampers

The amount of outside air is specified in the building’s design, however it is often adjusted later as a quick-fix for short term issues, leading to bigger problems in the long run.  It is common to find improperly installed and inoperable outdoor air dampers, which negatively impact the building pressure.   The dampers will need to be adjusted to proper position and outside air intakes may also need to be installed to achieve desired airflow.

Improperly installed air dampers

Above: Improperly Installed Outside Air Dampers (sealed closed with caulk)


5.   Check for negative building pressure in your facility

The tell-tale sign of negative building pressure can be found with using the door test.  A quick way of checking your building’s air pressure is to test it with a lighter or a match at an exterior door.  Crack the door open and place a lighter in the crack as pictured below.  If the flame pulls toward the inside of building, then the building is negative.

Door lighter test


Above: If flame pulls toward inside of building, the building is negative.


6.  Has your facility undergone a remodel, renovation, or a major change in equipment?

Remodels, renovations, or major equipment replacements change the distribution of airflow and requires an air balance service.  HVAC equipment installed in a building will not function at design specification at start up.  Adjusting the system to design specification requires testing, adjusting, and balancing.

These are 6 examples of what your mechanical contractor may discover in their assessment process.  If they are able to find and properly resolve the HVAC comfort or efficiency issues, then your troubleshooting may end here.  If not, you may need to consider calling in a certified test and balancing firm.  See our next post in this series for understanding what to look for in a test & balance contractor.

Additional Reading:

  1. Bringing in an Air Balance Contractor, Larry Moore, Melink Test & Balance
  2. Angela Hughes, a Red Lobster Facilities Manager with distinguished technical knowledge of HVAC systems, authored a very practical approach for FMs to self-diagnose comfort problems without prematurely spending money on contractors. Staying On Top Of Comfort Concerns
  3. For suggestions on preparing for an air balance, read Optimizing Air Balance Report Data  by Greg DuChane, Retail-Restaurant Vertical Market Director at Trane

DuChane, Greg. “Optimizing Air Balance Report Data.” Trane Tracks (Apr. 2015): n. pag. Trane. Web.

Hughes, Angela. “Staying On Top Of Comfort Concerns.” Facilitator Magazine Apr/May (2015): 66. Restaurant Facilities Management Association, 25 June 2015. Web. 26 Aug. 2015.

Melink Test & Balance Technicians. HVAC Deficiency Images. Digital image.Melink Test & Balance. Melink Corporation, n.d. Web. 26 Aug. 2015. .

Do Any of These 4 HVAC Issues Occur at Your Restaurant?

Are you contracting out your preventative maintenance?  Unfortunately, we’ve seen a lot of restaurant managers be misled by their mechanical contractors into thinking their “building is balanced”, but still notice misreported or never- reported problems that are causing complaints from their guests.  For example, you’ve been told that air filters and screens used for the outside air intake are clean, or that belts are tight, when they are in fact loose or cracking and ready to break.  These facility problems would cost so much less if treated immediately.  For example, a $10 fan belt replacement, if not replaced by your facility management when needed can cause irreversible damage to the rooftop RTUs, along with the cost of uncomfortable guests.  These instances escalate in the summer and fall months, when outdoor weather threatens indoor comfort.

Be aware of these frequent summer sick building symptoms, so you can call out the indicators, if necessary:

  1. Humidity- Sits in the carpets or hardwood floors causing buckling, odor, and mold.  Often triggers allergies for guests.
  2. Too much exhaust and little or no fresh air-causing a negative building pressure, so anything in the outside air can come in, including bugs and pests.
  3. Condensation on windows and/or grills
  4. Entry doors hard to open- Leaving guests frustrated, or worse-assuming the restaurant is closed

All the above issues can cause a negative building pressure, allowing the outside air to infiltrate the building through every crack and crevice, causing damage that could shut a restaurant down from a health code standpoint. If you’re concerned that your building is uncomfortable or not running how it was designed to, you have the option of calling in a third party HVAC balance service who can give you an objective diagnosis of the issue, and fix it.