Overcoming Shortfalls of Natural Ventilation by Using Mechanical Ventilation

1/31/2015

A well-ventilated home or building is important for the health and comfort of those who live in them, as well as longevity of the structure itself. While natural ventilation is an option, it presents some challenges that mechanical ventilation systems are able to avoid. When considering your home or building’s ventilation system and possibilities for improvement, be sure to take into account the shortfalls of natural ventilation.

Issues with Airflow

A notable shortfall of natural ventilation is the difficulty in controlling the building’s airflow. A fully-functional natural ventilation system requires careful planning and attention to pressure differences in air entry and exit points. These pressure differences are what encourage old air to exit the building and new air to enter at appropriate amounts. The functionality and performance of a natural ventilation system also depend on the climate and weather, which may cause sub-par performance when regions experience changes in weather on a daily and seasonal basis.

Allergens and Pests

More simple methods for natural ventilation involve opening doors and windows around the house or building. While this is a common method for letting out old air and introducing new air, it’s also a good method for introducing bugs, allergens, and other unwelcome guests. This can lead to an overall decrease in the indoor air quality and comfort for the building occupants.

Temperature and Energy Issues

Natural ventilation directly opens buildings to the outside air. This can become a big issue for those who live in areas that get very hot in the summer or very cold in the winter. By relying on natural ventilation in these types of regions, inhabitants will inevitably experience comfort issues in terms of temperature. Additionally, natural ventilation reduces energy efficiency in areas that require heating in the winter and cooling in the summer. Openings in the building allow heated and cooled air to escape, thus essentially wasting energy.

Overcoming Shortfalls by Using Mechanical Ventilation

Mechanical ventilation such as an energy recovery ventilator (ERV) or heat recovery ventilator (HRV) provides a solution to a number of issues presented by natural ventilation.  A Zehnder HRV or ERV works to exhaust air from moist rooms like bathrooms and kitchens while introducing a balanced amount of fresh filtered air into habitable spaces like bedrooms and living rooms.  While natural ventilation is an option, there are a number of variables and reliability issues that should be considered when designing an energy-efficient building.  With high-efficiency mechanical ventilation systems, home and building owners have greater control of proper building ventilation, regardless of external factors like the weather or the time of year.