Tag: sick building syndrome

Indoor Dew Point: Maintaining Thermal Comfort, Avoiding Building Damage

Posted on by Lindsey Burbee

Condensation and Moisture Risks in Buildings

Condensation, moisture absorption and, subsequently, mold or organic growth are often a result of high indoor dew point combined with cool surface temperatures. For example, if a facility’s indoor dew point is above 60oF, it is possible that moisture will begin to condense on cool surfaces like ductwork, chilled water supply lines, windows, or refrigeration systems. This collection of moisture can cause damage to the building, as well as to merchandise. It can even promote organic growth over time.

 

 

 

In addition to the risk of moisture accumulation, ASHRAE recommends maintaining a dew point below 62 oF to meet thermal comfort for approximately 80% of occupants; a dew point of 45 oF is recommended to maintain summertime humidity comfort levels.

 

 

Monitoring Dew Point

Consider this: You are a kid in a candy store with a plethora of delicious options in front of you. You sort through the store and boil your decision down to two candy bars.

Option A: The tried and true milk chocolate bar. Nothing fancy but classically delicious.

Option B: Fluffy nougat topped with caramel and peanuts, coated in milk chocolate. An exciting snack bursting with flavor.

Did you choose Option A or Option B?

If I had to guess, you chose Option B as it gives you more variety with your purchase! Now, what if I told you that the decision you just made also can apply to thermal HVAC design and dew point monitoring principals?

Option A: A design principal of maintaining 60% relative humidity (RH).

Option B: A design principal of maintaining a 60oF dew point.

Both are similar and help maintain a healthy building, but maintaining a 60oF dew point (Option B) is inherently better and offers a more reliable risk indicator. Using 60% RH as an indicator (Option A) is unreliable as it creates needless concern when air temperature is cool. In the example below, you can see that the amount of water vapor in the air remains the same while relative humidity concentration varies depending on the temperature of the air.

 

 

Image Source

 

Conversely, a facility manager or building owner may have a false sense of security when indoor air temperature is above normal levels because relative humidity will decrease as air temperature rises. These reasons are why dew point should be used as a threshold of concern. Dew point will not only factor in moisture content and temperature of the air but also provides a risk indicator for condensation and moisture absorption, which should be a facility manager’s primary concern.

 

 

Using Indoor Dew Point as a Risk Indicator

If you are already using indoor dew point as a risk indicator for indoor moisture activity, then continue to do so! Specifically, look to ensure that indoor dew point remains below 60 oF during cooling operations to reduce the risk of moisture absorption, condensation, and organic growth.

If you are not using indoor dew point as your risk indicator, now is the time to do so! You could be surprised to learn that measuring relative humidity alone may not be keeping your facility safe.

If you are already noticing signs of moisture accumulation, mold or organic growth, then ASHRAE recommends implementing the following HVAC factors to reduce your risk:

 

  • Dehumidify ventilated air to a dew point below the indoor dew point during cooling.

  • Drain HVAC system condensation effectively to prevent water buildup.

  • Prevent indoor surfaces from cooling below the indoor dew point in both occupied and unoccupied modes.

  • Keep indoor dew point low enough to stop condensation on HVAC components, building materials, or furnishings.

  • Install and control humidifiers correctly to avoid adding excess moisture to the air.

  • Insulate HVAC and plumbing components so their surfaces stay about 10°F above the indoor dew point.

These simple steps — in addition to proper HVAC ventilation, indoor air monitoring, indoor air verification, and keeping an eye on seasonal changes — can help ensure that your facility is operating in a safe manner while reducing risk of mechanical damage, moisture accumulation, or organic growth.

If you would like to learn more about ways in which your indoor air environments can be improved, please reach out to us. Please complete our contact form or contact us by phone at (513) 965-7300.

Window condensation is a sign of Indoor Dew Point

How Do Seasonal Changes Affect Building Health?

Posted on by Lindsey Burbee

Seasonal Changes and Building Health

As we transition from dry, cool winter months to hot, humid summer, you may be saying, “Woohoo! Bring on the heat!”. However, seasonal changes can affect building health. Specifically, the summer season presents major problems for facility managers and building owner. This is because their buildings’ HVAC systems struggle keeping up with increasing cooling loads and extremely humid outdoor air.

Just as spring plant life sprouts, HVAC mechanical issues can pop up with warmer temperatures. Poor indoor conditions, like high indoor relative humidity, negative building pressure, CO2 buildup, and temperature fluctuations are some examples.

Staying ahead of these issues before they become noticeable, costly problems is crucial when considering the overall health of your building and its HVAC systems.

 

 

Humidity: A Common Seasonal Issue

At various facilities, a common issue that comes with changing seasons is humidity. Specifically, humidity can be difficult to maintain at a comfortable level.

 

 

Condensation on building window, a seasonal building health issue.
Condensation in office building

 

In the winter, the heating mode on air handling equipment can heat or evaporate the existing moisture in the air to reduce the overall relative humidity as outdoor air is brought into the building. However, in the summer, the opposite occurs: the air handling equipment cools the building space and doesn’t heat or evaporate the moisture out of incoming air. This combination of high relative humidity and indoor dew point ultimately creates conditions that promote condensation or organic growth within the facility.

 

 

A Year-Round Solution for Indoor Building Health

The most cost-effective solution to verifying and ensuring long-term indoor building health is with a sensor capable of measuring key building health metrics like differential pressure, relative humidity, dew point, temperature, and CO2.

 

 

Components of building health

 

By gathering data on building health metrics, the facility manager can quickly verify on-site conditions in real-time. As a result, they gain peace of mind knowing their buildings meet engineering specifications per design. In addition to these benefits, sensor data gathering gives users the ability to track and trend building health over a long-term period.

 

 

Using Data to Plan for Seasonal Building Health Changes

Getting and staying ahead of maintenance doesn’t need to start with expensive truck rolls and frequent site visits. Instead, sensor solutions provide inexpensive, effective avenues to implement proactive mindsets. Collected data can be aggregated into easy-to-use online portals, capable of summarizing, visualizing, and diagnosing issues on site. Allowing users, the ability to predict HVAC performance for a lasting solution.

Get ahead of the changing seasons by verifying your building is healthy today!

Healthy Buildings & Employee Performance: The Next Revolution ?

Posted on by Lindsey Burbee

Do you want to optimize your employees performance by 299%?  Increase cognitive ability in strategy development by 288%?

Yes! Of course, we all would love to fully optimize ourselves and those around us to maximize our potential and impact on the world.  What if the answer was all around us, literally allowing us to live, and also invisible.  According to new research focused on indoor air quality in the work place, there is a tremendous opportunity to move beyond “green” buildings and ensure we work in “healthy” buildings. 

Source: Natural Leader: The Cogfx Study

The COGfx Study, while limited to 24 participants, demonstrated that improved indoor environmental quality doubled cognitive testing results in buildings with enhanced ventilation versus conventional buildings.  The study distinguished between three building types; Conventional, Green, and Enhanced Green.  Within these building types the focus benchmarks were Carbon Dioxide levels in parts per million (ppm), ventilation rates expressed in cubic feet per minute (CFM) per person, and Volatile Organic Compounds (VOC) in micrograms per cubic meter. It’s also worth noting that building used was already a LEED Platinum certified facility, thus there’s likely more room for increased scores when comparing older existing buildings.

Source: Natural Leader: The Cogfx Study

The study explores the decrease in energy efficiency, which could be viewed as a negative, however relative to the increase in employee productivity and lost time due to sickness the savings can be dwarfed.  The noted increased cost per occupant in energy consumption is $400/year, however the study suggest a 6 x return in sick leave reductions alone relative to the increased energy cost.  Factor in the potential for increased productivity for one of the biggest operational cost for any company, the people, and the energy penalty is worth the investment.

While Melink is focused on energy efficiency, we’re also not blind to the impacts of IAQ and built our corporate HQ as a LEED Gold facility, later upgraded to Platinum.  In addition to the LEED standards, we also monitor in door CO2 levels via sensors and increase ventilation rates via a HVAC purge sequence once the room exceeds 800 ppm in CO2.  On average, the general office area CO2 levels hover around 600 ppm and are aided by the addition of live plants which produced an average drop of 100 ppm in CO2.

This focus on IAQ has led us to the development of a new product, Melink PositiV, to help ensure proper positive building pressure and CO2 levels in commercial buildings. The aim is to provide a simple solution for one of the biggest problems in all buildings, restaurants and retail locations; negative building pressure.  The standalone device will monitor pressure, temperature, relative humidity, and CO2 levels and provide a picture of building health and trends.

Top 5 Negative Building Pressure Problems

Posted on by Lindsey Burbee

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.

Is Your Business Haunted Or Is It Something Worse??

Posted on by Lindsey Burbee

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!

A Balancing Act: Air Balance is an important part of HVAC maintenance

Posted on by Lindsey Burbee

When it comes to HVAC, no news is good news for restaurant facility managers. When you start hearing chatter about the building being hot and humid, drafty, smoky or uncomfortable, you know a problem has already taken root. It’s like a piano being out of tune. In addition to unhappy customers and employees, comfort issues are indicators of energy inefficiency within a system and air balance issues. So, what can facility managers do to prevent comfort and energy threats?

Identifying Common Problems

“Facility managers need to be trained on air balance and push it to their service contractors,” recommends Jeff Dover, resource manager at RFMA.

A good place to start is to gain a foundational understanding of building pressure and common HVAC deficiencies along with following seven easy steps to bring your restaurant back into tune. Most importantly, learn how to look for negative building pressure. Remember, the goal is to stay slightly positive in building pressure.

There are three methods to identify negative building pressure. The first and most reactive method is to monitor signals that your building is negative. These signs are hot/cold spots, entry doors that are hard to open, poor smoke capture, humidity, condensation dripping from diffusers and drafts.
Second, you can measure the building pressure yourself or with the help of your service contractor by using a pressure reading tool such as an anemometer to get a ballpark pressure reading. The third and most accurate method is to hire an air balance firm to check the facility’s building balance once a year. If comfort-related issues or a negative building pressure reading are observed, then an air balance needs to be scheduled.

Investigating the Cause

What causes a building to become negative or unbalanced? The usual offenders are equipment deficiencies, improper preventative maintenance programs, and adjustment errors such as kitchen staff fiddling with thermostats or service contractors opening or closing dampers.

 Here are 10 example deficiencies you or your service contractors should be on the lookout for:
  1. Exhaust fans in poor condition
  1. Supply air leaking above ceiling
  1. OA dampers improperly installed
  1. Exhaust fans not sealed to curb or hinged correctly
  1. Dirty compartment/coil in the RTU
  1. Tops of diffuser not insulated
  1. Filters improperly sized for hoods
  1. MUA not operating properly
  1. Dirty indoor/outdoor filters
  1. Worn/broken belts

Achieving Air Balance in HVAC

Once you’re ready to bring a facility back into tune, there are seven easy steps to complete. These steps may be completed by the facility manager alone, but are more likely in partnership with a service contractor. To get started, pull out the facility’s previous balance report to use as a base line for data.

One Principal Engineer at a hamburger fast food chain overseeing thousands of locations explains how her team uses the air balance report to get started with troubleshooting comfort issues.

“The reports really are my first line of defense when someone says ‘Hey, my store is cold/hot/humid,’ she points out. “The first thing I do is pull out the TAB report and see what it says. I look at the punch list and ask was anything wrong? Not fixed? It helps when I have to remotely assess or diagnose problems.”

7 Steps to HVAC Balance

Whether the previous air balance report has been reviewed or not, proceed to the following steps:

  1. Ask the onsite restaurant managers what the complaints are from employees and customers.
  1. Turn on all HVAC equipment.
    • Verify thermostats are set to “FAN ON”
  1. Check building pressure with the flame test in different areas around the restaurant (Figure 3)
  1. Observe smoke capture
    • Is the hood in the correct overhang position?
    • Are there drafts along the cook line?
  1. Check for common comfort issues (hot/cold spots, entry doors that are hard to open, poor smoke capture, humidity, condensation dripping from diffusers and drafts).
  1. Inspect the equipment.
    • Are the filters clean?
    • Are the belts in good condition?
    • Are the exhaust fan wheels clean?
  1. Determine an intervention plan.
    • If some preventative maintenance actions and/or repairs need to happen, start with the service contractor.
    • If equipment is inoperable, have it repaired or replaced.
    1. If the preventative maintenance actions are in order and the problems persist, call in a certified air balance company that has experience with restaurants like yours.
Facility managers need to trust that their service contractors will notify them of airflow-related issues. Those technicians are out on the roofs and looking at the HVAC system components more than anyone else. If the restaurant has negative pressure or other out-of-tune symptoms, the service contractor needs to inform the facility manager right away. After all, you want your customers and employees to continue singing your praises. 
Air Balance in HVAC

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

Posted on by Lindsey Burbee

HVAC Troubleshooting

Have you identified that your facility is experiencing a potential air balance problem?  You might be experiencing hard to open doors, uncomfortable temperatures, poor smoke capture, odors, drafty areas, or any combination of the other common sick building symptoms.  The inevitable question now is, “Who can resolve this best?” 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 grilles to see if air is being blown out or sucked in. Check roof equipment, 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 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. Your staff can 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 indoor and outdoor circuit breakers. Observe tripped or “Off” breakers. DO NOT flip the breaker on. If tripped or left off, there’s 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 can 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.