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CASE STUDY: EDUCATION FACILITY INDOOR AIR QUALITY

Commercial HVAC Indoor Air Quality: School Humidity Control Case Study

As one of the Mid-Atlantic region’s trusted integrated facility service providers, The Tustin Group helps organizations improve commercial HVAC indoor air quality through mechanical expertise, humidity control, building automation and coordinated facility solutions. For schools and other facilities facing temperature or moisture problems, improving commercial HVAC indoor air quality can support healthier indoor conditions, greater comfort and more reliable building performance.

The Tustin Group provides integrated services across commercial HVAC and mechanical systems, energy solutions and building automation, water solutions, fire and life safety, and security. This coordinated approach allows our teams to evaluate how individual building systems affect overall facility performance.


Education facility HVAC and indoor air quality project completed by The Tustin Group.

PROBLEM: EXCESS HUMIDITY AND INDOOR AIR QUALITY

A local school was experiencing significant HVAC and indoor air quality problems. The existing HVAC units were oversized for the conditioned spaces, which caused the equipment to short cycle.

Short cycling prevented the HVAC system from running long enough to remove sufficient moisture from the indoor air. As a result, excessive humidity developed throughout portions of the school.

The moisture problem became severe enough that walls in occupied areas were wet. In addition to creating uncomfortable indoor conditions, the excess humidity demonstrated that the existing HVAC configuration was not adequately controlling moisture within the building.

School leadership had also struggled to find a qualified contractor capable of evaluating the conditioned spaces, identifying the underlying HVAC problem and developing a practical solution.

COMMERCIAL HVAC INDOOR AIR QUALITY SOLUTION

The project began with a comprehensive HVAC system survey performed with assistance from a local engineering firm. The evaluation determined that the existing HVAC equipment was oversized for the conditioned space.

Working from the engineer’s recommendations, The Tustin Group installed reheat units to improve humidity control while allowing the existing oversized HVAC equipment to continue serving the facility.

The reheat strategy allowed the system to address moisture more effectively without simply overcooling occupied spaces. After installation, the team tested system operation and evaluated humidity conditions throughout the facility.

Testing showed that the updated system was operating within acceptable humidity levels for the documented project conditions.


Illustration of an HVAC reheat and air-distribution strategy used to support humidity control in an education facility.

RESULT: IMPROVED HUMIDITY CONTROL AND SYSTEM VISIBILITY

The improved indoor conditions were immediately appreciated by the building owners. More importantly, the project addressed the humidity-control issue identified during the system evaluation.

Following the HVAC improvements, the client selected The Tustin Group to install a building automation system. The system provided greater visibility into HVAC operation and helped facility personnel monitor the equipment and indoor conditions from a centralized platform.


Building automation provides centralized HVAC monitoring, system visibility and operating information for facility personnel.

The client also entered into a maintenance agreement with The Tustin Group. Ongoing service provides an opportunity to review system performance, address developing issues and support the HVAC equipment before smaller problems become more disruptive or expensive.

For facilities interested in proactive equipment monitoring, The Tustin Group also provides predictive maintenance strategies that use operating information to help identify changes in equipment performance.

WHY HVAC HUMIDITY CONTROL MATTERS IN SCHOOLS

Temperature alone does not determine indoor environmental conditions. Commercial HVAC systems also need to manage moisture, airflow and equipment runtime appropriately for the spaces they serve.

Oversized equipment can reach a temperature set point quickly and shut down before completing an effective dehumidification cycle. This repeated short cycling can make humidity more difficult to control even when room temperatures appear acceptable.

Schools present an especially important application because classrooms, offices, common areas and other occupied spaces can experience changing loads throughout the day. Proper equipment operation, controls and monitoring can help facility teams respond to those changing conditions.

For more information about commercial HVAC, building automation, facility performance and indoor environmental strategies, visit The Tustin Group’s News & Trends resource center.

PROJECT MEASUREMENT NOTE

The documented project states that post-installation testing showed the system operating within acceptable humidity levels and that the building owners reported improved indoor conditions. The available project information does not provide specific pre- and post-project relative-humidity percentages, audited energy savings or an independent indoor air quality dataset. Therefore, no numerical reduction in humidity, energy use or other performance metric is attributed to the project beyond the documented results.

COMMERCIAL HVAC INDOOR AIR QUALITY FAQs

What caused the school’s indoor air quality problem?

The project evaluation determined that the HVAC equipment was oversized for the conditioned space. The units were short cycling, which limited their ability to remove sufficient moisture from the indoor air.

How can oversized HVAC equipment contribute to high humidity?

Oversized equipment can satisfy the temperature set point too quickly and shut down before running long enough to provide adequate dehumidification. Repeated short cycling can therefore make indoor humidity more difficult to control.

What solution did The Tustin Group install?

Following an engineering evaluation, The Tustin Group installed reheat units designed to improve humidity control associated with the oversized HVAC equipment.

How was the HVAC solution tested?

After installation, the updated system was tested and humidity conditions were checked throughout the facility. The project documentation states that the system was operating within acceptable humidity levels.

Was building automation added to the school?

Yes. After the initial HVAC improvements, the client selected The Tustin Group to install a building automation system that provided greater visibility into overall HVAC operation and indoor conditions.

Does The Tustin Group provide ongoing HVAC maintenance?

Yes. The school entered into a maintenance agreement with The Tustin Group to support ongoing HVAC performance and help identify developing equipment issues.

EXPLORE HVAC AND BUILDING PERFORMANCE RESOURCES

NEED TO IMPROVE HVAC PERFORMANCE AT YOUR FACILITY?

Commercial HVAC problems involving humidity, short cycling, controls or equipment performance often require more than a single equipment adjustment. The system, controls and conditioned space should be evaluated together.

Ensure your commercial HVAC system operates as effectively as possible by scheduling a no-cost building performance evaluation with The Tustin Group.

Contact The Tustin Group to discuss HVAC performance, humidity control, building automation or integrated facility services.

The Tustin Group

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