Tag: air flow hvac

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!

We are less than 12 months from the R-22 refrigerant phase-out: How can companies prepare?

Posted on by Lindsey Burbee

What is R-22?

R-22 is an HCFC (Hydrochlorofluorocarbon) refrigerant found in older commercial and residential HVAC equipment, such as RTUs (roof top units), split systems and other equipment.  R-22 and other HCFC refrigerants are known to deplete the Earth’s protective ozone layer and contribute to harmful climate change.

The US has slowly been phasing out the use of R-22 per the following phase-out schedule:

  • 1/1/2010: The US government banned the use of R-22 in new HVAC equipment.
  • 1/1/2015: The US government bans the production and import of all R-22
  • 1/1/2020: The US government will ban the use of all R-22 (with a few exceptions).  This will be the end of the road for R-22 use in the US.

NREL (National Renewable Energy Laboratory) estimates 40 million commercial RTUs (roof top units) were installed in the US, in the decade prior to 2010.  The US Department of Energy also estimates that are at least 1.6 million old, low-efficiency RTUs in operation in the US.  This means there is a huge tidal wave of R-22 equipment in operation that will need to be replaced in the very near future.

How does the 2020 ban affect me?  R-22 costs have skyrocketed and are already more than 4X the cost/lb. of R410A. Older R-22 units have much lower EER ratings and are as much as 50% less efficient than current-day high-efficiency units.  In most cases, older R-22 RTUs cannot be converted to R410A refrigerant, and the older units will need to be replaced with a new, more energy efficient, more environmentally friendly RTUs.  It is already cost prohibitive to repair older R22 units, and the “fix-on-fail”, emergency replacement philosophy will be MUCH more expensive than a pro-active roof-sweep or planned equipment replacement program.

How can I best prepare for the phase-out, and where should I start?  I recommend companies start with an HVAC inventory of their older equipment, in addition to a detailed survey of all their facilities to verify the age and condition of all HVAC equipment, including newer and older HVAC equipment.  I also recommend involving a national or regional HVAC installation partner, and an independent, national testing, balancing and commissioning partner such as Melink Corporation to provide the unit data and a complete assessment of the entire mechanical system.  The survey should include duct-work inspections, inspection of the RTUs and exhaust fans.  Additionally, air-flow measurements should be recorded to verify proper building airflows and identify existing air-balance issues.  If the entire HVAC system is not inspected, the building will often continue to have comfort problems and building balance issues, even after the new equipment is installed.  The positive effects of the new, energy efficient HVAC equipment will not be fully realized, resulting in a lower-than-expected ROI.

  • For further information on HVAC surveys and other custom scopes of work, please e-mail [email protected] or call us at 513.965.7300.

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.