Environmental Factors: Performance of essential functions may require exposure to adverse environmental conditions, such as dirt, dust, pollen, odors, wetness, humidity, rain, fumes, smoke, temperature and noise extremes, hazardous materials, fire, unsafe structures, heights, confined spaces, machinery, vibrations, electric currents, traffic hazards, bright/dim lights, toxic agents, animal/wildlife attacks, animal/human bites, explosives, water hazards, disease, pathogenic substances. Performs preventative maintenance on HVAC systems and equipment: obtains electrical readings to determine condition of motors, controls and compressors; replaces air filters; cleans condenser and evaporator coils; obtains refrigerant pressures and temperatures; determines correct refrigerant charge; and inspects gas supply lines, gas exhaust piping and electrical connections for tightness and safety.