Comfortable cooling at comfortable cost

Edward Dsouza, President, ServiceMASTER India

Thermal comfort is fundamental to the wellness of a building’s occupants, but the cost of maintaining temperature and humidity within an acceptable range may be a constant burden on the building owner. By measuring and analysing various indoor air parameters and operating the HVAC system accordingly, facility managers can optimise consumption of energy, water and filters, writes Edward Dsouza, President, ServiceMASTER India.

Air balancing

This is the process of optimising an HVAC system to ensure uniform distribution of air cooling throughout the indoors, irrespective of various factors contributing to hot-cold pockets. Our team has a systematic approach for conducting periodic/SOS HVAC air balancing to improve indoor air quality:

• Identification of hot-cold areas through proper logs.
• Charting variance from standard readings.
• Analysis of ambient conditions.
• Reviewing last balancing reports and adjustments.
• Analysing any change/rework in infrastructure causing imbalance in air flow.
• Analysis of amount of air volume supply and volume return.
• Analysis of ACH/CFM distortion as per design versus actuals.
• Analysis of peak and surge logs of temperature/humidity with durations.
• Execution of air balancing through coarse and fine adjustment.
• Post execution report analysis and sign-off.

We ensure timely and proper air balancing to save on additional cost of water and energy that is consumed to meet additional cooling demand of the work floor. This is not the actual cooling demand but becomes the demand because the distribution of air flow is not as designed.

Conserving water & energy

In order to maintain standard temperature and humidity, we must have an operational and monitoring approach towards wastage of cooling and variance of humid conditions. Due to wastage, demand for cooling increases and thus, the compressor target goes high, ending up with excessive energy consumption and additional water consumption.

Role of sensors

We propose continuous monitoring of the following parameters through smart sensors so that real time information can be obtained through an IoT-enabled dashboard. This helps in real-time remedial action, improving adherence to sustainability.

We suggest continuous monitoring of indoor air for various parameters, which helps in auto correction. The unmonitored parameters become a reason for excessive energy consumption/increase in water consumption/additional machine run, thus hiking maintenance cost.

Smart sensors and AI-based applications work together to ensure real-time logs. This helps us plan early actions/remedials as required to avoid adverse/prolonged effects of poor IAQ.

Activities like auto start of exhaust fan, controlling fresh air requirements and maintaining the level of oxygen at the work floor can all be configured through IoT-based applications. The various sensor we propose and configure are:

• Temperature sensors
• Humidity sensors
• Differential pressure sensors
• Position sensors
• Flow switches
• Vibration sensors
• VFD
• Network switches and sensors

Role of filters

In order to arrest most of the solid contaminants and biological contaminants up to some extent, cleaning/maintenance and timely replacement of filters is significant to HVAC operations. Frequent change of HEPA/MERV/PAF/fibreglass filters is a costly affair and difficult in cost-sensitive circumstances. Hence, we recommend use of ultraviolet filters for continuous disinfection of biological contaminants. For solid contaminants, regular and cost-effective filters are available.

To assess the performance of filters, we need to regularly check on: CFM, ACH, frequent need for air balancing, hot/cold pockets, VFD functions, differential pressure analysis, energy consumption trend and reduced cooling efficiency.

Other interventions

Indoor air has three types of contaminants: solid, gaseous and biological. Basic sources of indoor air contamination are: Flying dust from outdoors, through fresh air mixing, duct moisture, footfall, building material/fabric, goods movement, paint/toxic carbon compounds, on-site cooking/pantry, furniture/household rodent/pest, infected individuals etc

The one solution which is commonly applicable in controlling the above three types of contamination is cleaning/matting. Mats are fundamental hideouts of the dust/PM 2.5 and PM 10. Matting must be done with isolation to be effective in controlling air contaminants.

We suggest a smart cleaning kit and procedure to have an effective check on indoor air contaminants.