Ventilation contributes to human comfort. Air inside an occupied building can become stale and stagnant. In hotel, activities such as smoking and cooking tend to magnify this problem. Consequently, the air in the building needs either to be filtered or to be replaced with fresh outside air. The replacement of inside air with air from the outside will raise heating and cooling costs because this outside air must be brought to the inside air temperature; thus a good air filtration system may be a cost effective investment. In addition, building surroundings that allow free movement of winds may have positively impact on ventilation.
Buying a ventilation system based strictly on low price is generally not a wise economic decision in the long run. A well insulated building is always easier to ventilate than one with too little of poor insulation. The ventilation system also interacts with the heating and cooling systems. Ventilation requires air movement and this can have a cooling effect. Heated or cooled air is sometimes distributed around a building by ventilation assisted air movement; when this occurs, the ventilation system becomes a part of the heating and/or cooling system. Thus, although the ventilation system alone is responsible for providing fresh, clean air, all the elements of the HVAC system must work together to provide the most comfortable combination of temperature, humidity, and air speed. For the last 20 30 years, manufacturers of HVAC equipment have been making an effort to make the systems they manufacture more efficient. This was originally driven by rising energy costs, and has more recently been driven by increased awareness over environmental issues.