Most people understand the two basic functions of an HVAC (heating, ventilation, and air conditioning) system–the heating and air conditioning parts are well understood. However, the ventilation function often isn't well understood. Next time you're looking into HVAC repair or service, considering installing mechanical ventilation. Here are some of the reasons you need mechanical ventilation and can't just rely on natural ventilation of the house:
Controlled Fresh Air Movement
One of the best things about mechanical ventilation is that it allows you to control the movement of air in to and out of the house. This is a big deal because uncontrolled air movement may introduce too much air into the house or remove too much air, both of which are bad. For example, bringing in too much air or removing too much air makes the HVAC work harder than usual to cool or heat the incoming air, as the case may be. This reduces the HVAC's energy efficiency. By using mechanical ventilation, you ensure that only the right amount of air is moved in or outside the building, thereby maintaining HVAC efficiency.
Controlled Source of Fresh Air
Apart from helping you control the amount of air leaving or entering the house, mechanical ventilation also allows you to decide which side of the building you want your fresh air to come from. This is important if one side of your house has foul air, for example, if there is a nearby highway, dumpsite, or even a restaurant that emits strong odors. In such a case, the mechanical ventilation can be designed to bring in air only from the fresh sides of the buildings.
No Dependence on Outside Weather
If you rely on natural ventilation, then the amount of air coming into your house will be largely influenced by the prevailing weather. For example, this means that your house may be starved of adequate air during moderate weather when there is no wind and the air isn't too heated either. At the same time, strong winds may blow too much air into your house. This is bad because the weather is uncontrollable; the good news is that you can avoid it using mechanical ventilation.
The Possibility of Cleaning Fresh Air First
Lastly, mechanical ventilation allows you to clean the air coming into your house even before it gets to the HVAC filters. This is not only good for your indoor air quality, but it also eases the work your HVAC system has to do to clean the air. With natural ventilation, the air will just be seeping into the house with all its contaminants from outside.