Tag: negative building pressure

How Restaurants Can Verify Proper Ventilation for Health & Comfort

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If you have owned or operated a restaurant, you are familiar with the challenges of maintaining proper airflow throughout the building. From the kitchen to the front of the house to the back of the house, proper airflow can be challenging to keep in balance. That said, restaurants go out of balance for many reasons, wreaking havoc on a building’s health, comfort, and ventilation.

Does your restaurant look like this?

Restaurant Ventilation Problems

Unfortunately, these types of issues are extremely common in existing restaurants throughout the United States, and, when left unaddressed, can lead to negative building pressure, which causes serious long-term damage, poor indoor air quality, poor energy efficiency and uncomfortable conditions.

What are the industry guidelines for building ventilation?

ASHRAE 62.1 outlines minimum ventilation rates for various types of buildings, as well as other measures to ensure acceptable indoor air quality (IAQ) for human occupants.  In a nutshell, ASHRAE recommends a certain minimum amount of fresh outside air be introduced through the building’s HVAC system.  It also recommends that the proper amount of outside air be verified at least every five years. Without properly setting the outside air intake volume, buildings can experience negative building pressure and exhibit sick building characteristic. The best way to verify outside air is to hire a certified Test & Balance company, such as Melink, which has the proper air measurement instrumentation and years of experience.

How can I tell if my restaurant is properly ventilated?

  1. Observe restaurant conditions and ask staff for a log of comfort issues
  2. Turn on HVAC equipment, “Fan On” mode
  3. Check the front door for signs of negative building pressure
  4. Observe the kitchen hoods for proper smoke capture
  5. Check the restaurant for drafts
  6. Inspect the rooftop equipment to ensure it is in working condition
  7. Ensure your HVAC preventative maintenance services are being performed satisfactorily
  8. Contact Melink for building balance and comfort investigation services

How can I be sure my building stays healthy, comfortable, and properly ventilated for the long-run?

More and more restaurant chains are interested in the idea of “ongoing commissioning.”  With scant facilities budgets and facilities managers stretched ever thinner, it is not feasible to routinely send someone to each facility to verify building health, ventilation, and comfort. Out of this necessity, Melink’s PositiV® Building Health Monitor was born. PositiV is a standalone system that monitors your building’s pressure and remotely tracks building health. Alerts are sent when the system detects anything is out of set parameters. Moreover, PositiV monitors temperature, relative humidity and CO2 so that you gain a full picture of the health of your facility. 

Melink PositiV Building Health Monitor

PositiV is THE solution toward being able to actively monitor restaurant health, comfort and ventilation for the long-haul, and it is the most affordable way for multi-site facility managers to proactively stay ahead of building health issues before they become big facility problems.

Below is a REAL restaurant’s PositiV data. The site is taking action to improve negative pressure and building ventilation issues before they cause building damage, mold and comfort problems.

Restaurant Ventilation Case Study Example

Ensure Your Restaurant’s Ventilation & Air Quality

For further information restaurant ventilation and PositiV (ongoing commissioning), please e-mail [email protected] or call us at 513.965.7300.

Prevent Sick Buildings: Why Positive Building Pressure Matters

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Can a building get sick? I’ll give you the answer up front: Yes, sure, most definitely — a building can get “sick.” You may ponder… “But how can a building become sick? It is an inanimate object. It doesn’t live and breathe like humans!” On the contrary, your building is a living object. The main factor making your building come alive is its people: your customers, employees, and outside partners (think mail delivery or an overnight cleaning crew). Let’s dive into what factors can make a building sick and why maintaining positive building pressure is so important in prevention.

What Makes a Building Come Alive?

First, consider what may make your building come alive (or ultimately “infect” it):

  • Supplies
    The products you bring in (from any point of origin) may have outside contaminants or be perishable. As you know, perishables may emanate odors or fumes.
  • Chemicals
    You must account for chemicals or cleaning supplies in their controlled rooms (where exhaust is extremely important). 
  • Restrooms
    Consider the restroom facilities. Restrooms, especially those open to the general public (i.e. in a lobby area) can encounter high volumes of traffic and behaviors that may not meet sanitary standards. 
  • HVAC System(s)
    Your HVAC system is a key element bringing your building to life. With proper cleaning and maintenance, they are designed to provide comfort on demand. Heating and cooling are crucial amenities that have grown to be a must-have and are mandated by federal and local guidelines. 

When you take all these factors into account, it’s easier to understand how a building can become “sick.”

Sick Building Syndrome symptoms

Facility Managers: How to Prevent Sick Buildings

So how can a facility manager or building owner help to prevent sickness in a facility? As a professional in the HVAC industry, my primary goal is to earn your trust to maintain the wellness of your building’s HVAC system. Think about it — you can’t control others’ actions. There is no way to determine someone’s state of health as they are in your establishment. But you can control the HVAC system and make sure it is properly maintained to be a healthy system!

A little-known fact about HVAC systems that I will stress the importance: FRESH OUTSIDE AIR IS NEEDED TO MAINTAIN A POSITIVE BUILDING PRESSURE AT ALL TIMES. What does this mean, and why is it important?

  1.  Your restaurant, retail store or office building, has many moving parts to bring it alive, has to breathe. Like any living thing, it requires oxygen to replace the carbon dioxide. The equation should result in bringing in a greater amount of fresh air than the carbon dioxide, chemicals, fumes/odors, and cooking effluents that the building creates. When this happens, there should be a slight positive pressure from the inside of your establishment that pushes outward at your doors and drive-thru windows.  A proper HVAC test and balance (TAB) by an NEBB-Certified firm like Melink can help you achieve this goal.  

  2. A common oversight that people make is assuming, “My building is positive. We’re in good shape.” But how sure are they that the lungs of the HVAC system are clean and free of operational damages? Many times, I have encountered damaged and clogged filtration components within an HVAC system that may lead to costly repairs to your equipment and structural damages:
  • Clogged or missing outside air intake filters
  • Clogged, missing or inadequate air filters
  • Clogged evaporator and condenser coils
  • Clogged and inadequate fan blower wheels
  • Mold and mildew
  • Trapped small animals that lead to contaminations
  • Contaminated duct work that eventually shows up on the supply, return and exhaust grilles throughout the establishment 
Checking HVAC ductwork for positive building pressure

All these issues work together to create a sick building.  The opposite of positive pressure is that dreaded negative pressure. Every time your facility’s doors open, all of the outside air conditions are sucked into the building.  These elements can be hot or cold air, humidity, airborne pathogens, and odors. The humidity attaches to the chilled supply diffusers and grilles, creating moisture buildup that drips onto your floors, tables, customers, and clients.

Checking HVAC filters for positive building pressure

Of course, it’s not feasible for a facility manager to know the ins and outs of every HVAC system of every facility he/she manages. So let us do the work for you! Melink Corporation’s T&B technicians can be your eyes and ears to help your facilities maintain positive building pressure. We are an army of application engineers with skilled LEED and NEBB certifications. Our company is nationwide and has more than 30 years of experience. Along with services that will help you on your way to a healthy building, we offer a monitoring system and demand ventilation systems that will alert you when problems or concerns arise.  These services, along with reliable routine maintenance will minimize uninterrupted service to your most important people. We can help you protect your customers, employees, and outside partners from sick buildings.

COVID-19 Closures: Mitigating Damage to Unoccupied Buildings

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As states across the U.S. are working to flatten the curve, many businesses are impacted by COVID-19 closures as a result of “stay at home” or “shelter in place” orders to limit human interaction and prevent the virus’s spread. Additionally, many companies across the country have opted to temporarily close facilities to prevent employees from contracting the disease. With these shutdowns, it can become increasingly difficult to determine the condition of a facility and repair any issues that could be developing while the facility is unoccupied.

COVID-19 closures of restaurants

Damage to Unoccupied Buildings

Consider these scenarios that could arise in an unoccupied facility…

  • A building in the coastal region may experience high humidity that is going unnoticed, which can in turn lead to mold growth. Imagine if the facility is a retail store; the end-result might mean thousands of dollars of damaged, unsalvageable clothing merchandise.
  • If indoor moisture levels drop too low — perhaps in a cooler climate that is shifting from winter to spring temps — it could lead to wood warping. For instance, the frames of wood windows can shrink in size, making them more difficult to open and potentially creating gaps that let in more cold, dry air.
  • Low indoor moisture can also lead to peeling or separated wallpaper, or cracked paint on plaster walls. What would you do if you come back to your facility, only to realize you need to bring in professional painting or remodeling services?
  • Think about a restaurant or bar. There may be hundreds (or thousands) of dollars of liquor or wine in stock, going untouched through the COVID-19 crisis. Corked bottles of wine are not exempt from the effects of dry indoor air. Extremely low humidity levels can slowly chip away at a cork, leaving room for air to get into the bottle and ruin the flavor. The ideal humidity level for wine storage is 60%.
  • Another thought for a restaurant facility: A humid environment allows mold growth to fester. The COVID-19 shutdowns came on suddenly for many facilities. Did kitchen staff have adequate time to scrub walk-ins, pots, and pans? Were grease traps thoroughly degreased? These are potential breeding grounds for mold during non-occupation.
  • Contemplate multi-purpose facilities, such as an apartment complex with retail or dining space on the first floor. Completely shutting down HVAC airflow to the unoccupied businesses could lead to uneven air flow and temperature throughout the larger building.

The bottom line: Scenarios like the ones above will go unnoticed and unrepaired until employees return to the facility to find the damage caused by an unoccupied month.

Preventing Facility Damage During COVID-19 Closures

While these issues may seem frightful, thankfully many state governments have kept issues like this in mind when mandating shelter-in-place orders. Seeing the value and necessity of essential services, many states are allowing skilled trades such as HVAC technicians to continue working. During quarantine, let these technicians be the eyes and ears at the facility to ensure that, when business returns, critical issues didn’t develop, delaying reopening.

In addition, this downtime can also be the ideal occasion to have technicians visit the facility to address any known issues or to perform preventive maintenance. Maybe there is a repair the facility manager has been putting off because its fix requires closing a typically busy corridor or lobby area. By addressing this work now while the facility is shut down, managers can limit future downtime, employee inconvenience, and lost profit.

And as a preventative measure for the duration of this closure or in preparation of future closures, consider installing sensors to remotely monitor a facility’s indoor air quality levels through relative humidity, temperature, building pressure, and CO2 checks. A system like Melink Corporation’s PositiV® building health monitor can remotely track and trend building health, plus send alerts to the facility owner or manager when the system detects measurements outside its set parameters. While a facility may not have this in place to combat the current COVID-19 closures, it can be installed now to prepare for future unplanned closures or even a vacation (Facility managers need a break at some point, right?!). 

PositiV and Test and Balance: A one-two punch to sick building syndrome

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Sick building syndrome is a condition that affects a building’s occupant due to unhealthy factors in the work environment primarily associated with poor ventilation and airflow in the facility. Per the EPA, symptoms of Sick Building syndrome include acute discomfort such as headaches, dry skin, coughing, dizziness, and nausea. Despite all these symptoms Sick Building syndrome can go undetected for years as the symptoms are all relatively minor and occur over multiple years.

With the release of Melink PositiV™ earlier this year, facility managers can now remotely diagnose and asses 4 of the key building metrics that contribute to building health. These include CO2, relative humidity, building pressure, and temperature. By ensuring these 4-building metrics are within acceptable ranges facility managers can sleep well knowing that they will be able to monitor and track if their facility is showing early signs of sick building syndrome. This can empower the end user to act and stop the early patterns that can lead to numerous issues down the road.

You know it is time to act when one of the 4 measurements are outside of the recommended limits. A primary way of attempting to correct any of these issues in a facility is to have a test and balance to reset airflow to the engineered design plans. During a test and balance, existing issues are identified and corrected to allow for proper airflow into the space. Through this process the technician should be examining and resetting the outside air dampers at the facility to allow the building to receive the correct amount of fresh air. The combination of monitoring and acting on the data allows end-users to ensure comfortable, healthy and energy efficient facilities.

Top 5 Negative Building Pressure Problems

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The difference between outside air supplied to a building and air removed from inside a building is the building pressure.  Typically, a slightly positive (or more air being supplied than taken out) building pressure is wanted for most buildings.  Negative building pressure can cause many issues for customers from high energy costs to hot and cold spots in a building.  Here are the top five problems a building with negative pressure can experience:

  1. Difficulty Opening and Closing Doors:

One of the first signs that a building is negatively pressurized, is when the front door is not easily opened.  After finally opening the door to a negatively pressurized building, a large draft will be felt on your back as the door is slammed closed.  Because buildings are typically designed to be positively pressurized, you should feel a soft gust of air blowing outward when this is set properly.

  1. High Humidity:

If your building is negatively pressurized, the building will pull in unconditioned outside air through all openings including doors, windows, and other leaks in the structure. This is very noticeable in the summertime when outside humidity is especially high.  This can cause mold or mildew in the building.

  1. High Energy Costs:

Studies have shown that correcting negative building pressure can save a facility owner as much as 20% on their HVAC energy costs.  By ensuring your facility has a positive building pressure, you are avoiding unnecessary costs and maximizing comfort in the facility.

  1. Outside Debris:

In a facility that is negatively pressurized, owners are more likely to see outside debris being pulled into the facility through various openings. These items include, leaves, flies, dirt, as well as smells brought in from outside.  In many facilities, this could create major issues with production as the outside debris could be contaminating the products.

  1. Hot and Cold Spots:

Another symptom commonly noticed in buildings with negative building pressure is noticeable hot and cold spots that are created by the disrupted airflow.  This could cause the customers to become angry because they can’t reach a comfortable temperature in the building.  In a restaurant, this could also cause food at the counter to become cold.

Air Balance Basics for Existing Facilities

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We all understand the concept of the “band-aid approach” whereby you find a quick cover-up to a problem without actually investigating the root of the it.  This concept applies very frequently in the context of a Facility Manager or Building Owner wrestling with HVAC emergencies that are being caused by negative building pressure. They will tackle issues such as condensation, hot/cold spots, humidity, odor, and difficult to open doors with band-aids of increased air conditioning, dehumidifiers, wet floor caution signs, door mechanisms, air fresheners, apologizing to patrons, comping customers’ bills, and so on.  This is understandable when you’re managing 80+ facilities, all with problems that stretch far beyond just HVAC.  However it comes with a cost of spending a lot of time, money, energy, and reputation just to have the issues continuing to come back.  While balanced airflow is not a tangible product that is easily seen or touched, the consequences of an unbalanced building are very perceptible.

Facility Managers are ready to de-mystify their HVAC issues with understanding of the root causes.  Use the air balance basics below to recognize when an issue is airflow-related.

What does it mean to have a balanced airflow?

Think of a financial statement with income listed in one column and expenses in the other.  Much like a budget where you want cash coming in to be at least equal to or greater than cash going out, you typically want the air going into a building to be slightly greater than the air going out.  Similarly, think of a balanced scale.  In the graphic below, air is being drawn out of the building by exhaust fans, to remove heat and smoke from kitchen cooking appliances and foul air from the restrooms, at a rate of 4000 CFM (cubic feet per minute).  Air is also being introduced into the building through an outside air fan, to provide fresh breathing air for the occupants and to replace the exhausted air, at a rate of 4500 CFM.  The result is a slightly positive building pressure of 500 CFM (4500 – 4000 = 500), which signifies a balanced airflow.  Conversely, if the air coming into the building is slightly less than the air leaving the building, then you have a negative building pressure, which is the frequent culprit of many HVAC problems.

Which brings us to a crucial pairing to the air balance concept.  That is if balanced airflow is peanut butter, than a performance test is the jelly.

What is an air test & balance service?\
 

An air balance testing service is the process by which the performance of HVAC airflow is measured.  Once it is tested, the systems are then adjusted, or balanced, so that the air brought into a building is slightly greater than the air being pulled out of the building.  The benefit for testing and balancing being a combined service is explained by Rob Falke, President of the National Comfort Institute, “This [positive] pressure condition can be designed, but to be sure it actually happens requires air diagnostic testing.  However, it’s hard to say how great the positive pressure reading in the building will be. It depends on how tight (or leaky) the envelope of the building is, and what other pressure generating forces exist, including the wind, appliances, exhaust fans, and the stack effect of the building.”  The result is a comfortable, healthy indoor environment with an HVAC system that is optimized to perform efficiently.

 Sources:

  • Digital image. Air Concepts LLC. N.p., n.d. Web.  Nov 25 2015.
  • Falke, Rob. “How to Measure Building Pressures.” Contracting Business, 1 May 2006. Web. 25 Nov. 2015.

3 Steps to Troubleshooting Your Facility’s HVAC With Onsite Staff

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Have you identified that your facility is experiencing a potential air balance problem?  You might be experiencing doors that are hard to open, uncomfortable temperatures, poor smoke capture, odors, drafty areas, or any combination of the other common sick building symptoms.  The inevitable question at this stage is, “Who is best to resolve this?” Bringing in your facility’s mechanical contractor may be your first instinct, but troubleshooting with your onsite managers is actually the best place to start. Work through the following questions with your facility’s day-to-day manager:  

1.  Is the equipment running?

As basic as this may come across, it is absolutely crucial to check if all HVAC equipment is operating. Check all grilles to see if air is being blown out or sucked in. Check the equipment on the roof, can you hear the fans from the RTU, MUA, or EF units spinning? Have the manager record and communicate findings.

2.  Check the thermostats

Navigate to the wall mounted thermostats and ensure that they have the proper set points. Often, a thermostat is installed and connected to the system and then left alone. When this occurs the thermostat is left at factory settings which is often set at a random temperature, maybe even 100 degrees Fahrenheit!  Your staff should be able to follow the directions on this thermostat to program it for the desired temperatures.  As well, check the thermostats for “Fan ON.”

Thermostat

3.  Check the Circuit Breakers

Check your indoor and outdoor circuit breakers. Observe if any of them have tripped or been switched to “Off.” DO NOT flip the breaker back on. If it is tripped or left off, there is likely a reason for it and you don’t want to risk frying the electrical systems. We recommend calling an electrician for this type of deficiency.

 

Armed with your findings from these simple tests, you may have been able to save some money with a Do-It-Yourself fix.  It’s possible that the journey back to a healthy building ends here.  But if the problem persists, it’s time for the level of technical know-how. Call the mechanical contractor. With your observations to these preliminary steps above, you can approach your mechanical contractor with information that will help them to better understand your situation and get you closer to achieving a healthy building.

The #1 Air Balance Bummer: Negative Building Pressure

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What’s the first thing you experience when you arrive at a restaurant? You might say the delicious aromas, lighting, and possibly the smiling hostess asking how many are in your party. But the very first thing anyone experiences is the door. How many times have you found yourself struggling to open the darned restaurant door? You pull the handle, but it won’t budge. You try the other handle, to no avail. You think, “There’s no way this is locked, it’s the middle of the lunch rush and I can see people inside.” With all your strength, you finally crack it open and squeeze through. You might feel a large draft on your back and then, finally, slam! Woman pulling on door

 If this common door problem has happened to you, how many times do you think it has happened to customers entering one of your restaurants? While your first hypothesis may be that it is a door hinge problem, it is actually part of a larger problem: negative building pressure. And that is just one symptom of a sick building.

 Sick Building Syndrome is a serious situation restaurant facility managers and owners cannot afford to take lightly.

Check out these three must-know tips:

  1. Know what to look for. This simple illustration shows the most common problems related to HVAC air balance, which cause sick building syndrome.  Educate your teams as well.

Unbalanced HVAC system problem graphic

  1. Assign someone at each restaurant location – the store manager or maybe a shift leader – to watch for these sick building symptoms. Give them a process for reporting these problems so you have a record of the issues.  View our Sick Building Syndrome white paper and distribute to your teams for diagnosing comfort problems.
  1. Don’t just take it from us, read more on this important topic from expert Rob Falke, How to Measure Building Pressures, published on ContractingBusiness.com, an online industry publication.

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

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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.