37 Installation, repair, maintenance, servicing and reconditioning of apparatus and instruments for monitoring, measuring, and checking in the nature of pressure measuring apparatus, apparatus and instruments for condition monitoring in the nature of monitors used in food manufacturing to determine levels of humidity, temperature, carbon monoxide, volatile organic compounds, nitrogen dioxide, ozone, nitrous oxides, carbon dioxide, particles, sulfur dioxide, hydrogen sulphinde, ethanol, indoor air quality, sulfites, alcohols, odorous compounds, respiratory irritants, chlorines, formaldehyde, ammonia, light pressure, sound pressure, air pressure, radon and biological contaminants, detection apparatus and instruments in the nature of infrared detection apparatus, remote monitoring apparatus in the nature of wireless controllers to remotely monitor and control the function and status of other electrical, electronic, and mechanical devices or systems, namely, air movement control devices, filtration devices and ventilation equipment, air monitoring apparatus in the nature of air pressure measuring apparatus, air measuring apparatus in the nature of air pressure measuring apparatus, air analysis apparatus, and air pollution measuring devices; installation, repair, cleaning, maintenance and servicing of ventilation installations and apparatus in the nature of cordless floor drying cone dolly, ventilation terminals in the nature of fans for HVAC units, ventilation hoods, industrial ventilation apparatus in the nature of ventilating fans for industrial purposes, ceiling fans, electric fans, electric fans for ventilation, motorised fans for ventilation in the nature of electric fans, fans for use in air conditioning and ventilation in the nature of fans for HVAC units, air inductor apparatus in the nature of air conditioning units, turbine ventilators, extractors in the nature of extractor hoods for kitchens, extractor fans for household use, air humidifying apparatus, air cleaning instruments and apparatus in the nature of air cleaning units, air purifying installations and apparatus in the nature of air purifiers, air handling installations and apparatus in the nature of air purifying apparatus, air conditioning systems in the nature of air conditioners, air conditioning filters, air filters in the nature of filters for air conditioning, air humidifiers, air moisturisers in the nature of air humidifiers, air sterilisers, air purifiers, air dehumidifiers, ionization apparatus for the treatment of air, air control dampers in the nature of dampers in the nature of control devices used in air ducts to regulate the flow of air, air freshening installations and apparatus in the nature of air purifiers, filters for air conditioning, air deodorising installations and apparatus in the nature of electric air deorizers, air circulation apparatus and installations in the nature of air purifiers, air recircling installations and apparatus in the nature of air purifiers, and air distribution units in the nature of fabric air dispersion ducts for distributing and dispensing air as part of a HVAC system; HVAC system installation, maintenance and repair; installation, maintenance and repair of HVAC systems