A ventilation system that is properly designed and installed can significantly reduce indoor air pollutants in the home. It can also be energy efficient, helping to lower your electricity bills. However, there are many options and the type of ventilation system you choose will depend on the climate where you live, the size of your home, and how much money you want to spend.
Ventilation systems are typically categorized as either affordable ventilation systems exhaust-only or central fan-integrated supply systems. Exhaust-only systems use fans in pollutant-creating rooms (kitchens, bathrooms, basements, and attics) to blow polluted air outdoors, while the air handler in the house pulls in fresh air. The cost of this kind of system varies, but it can be less than $2000 in some markets and is an affordable choice for homes that already have extensive ducts.
Most homeowners, including those looking to buy a new home, are interested in improving the quality of their home’s indoor air. But many are unsure what options exist for ventilating the home, and how much these systems cost to install. GBA Editor Martin Holladay recently wrote about the types of ventilation systems available to homeowners, and how the most affordable ones work.
Exhaust-only mechanical ventilation systems are the most affordable and easiest to maintain. The key is to make sure you get a high-quality exhaust fan and a good installation to ensure that the air gets pulled out of all rooms in the home, not just those that have a dedicated exhaust system.
Typically, these systems are used in smaller houses with open floor plans. They do not work well in larger homes or those with lots of obstructions that prevent the air from being drawn freely from the interior to the exterior.
The more expensive, but still relatively affordable, alternative is a heat recovery ventilator (HRV) or an evaporative refrigerant ventilation (ERV). These standalone units transfer some of the energy (heat) from exhaust air to incoming fresh air, preconditioning it and keeping humidity levels in check. An ERV differs from an HRV in that it transfers not just the heat energy but water vapor, making it better suited to climates prone to hot and humid summers.
Both of these systems are more complicated and costly to install, but they can save you even more in energy costs over the long run. In addition, they can improve occupant comfort by keeping humidity levels stable year-round.
The least expensive approach is to use a single-sided natural ventilation system. These systems use openings on one side of a building or home to vent air, using wind speed and temperature differences to create circulation. A demand controlled ventilation (DCV) system, on the other hand, automatically adjusts based on occupancy. It can run in conjunction with other ventilation systems, boosting the rate when necessary to meet specific design specifications. The cost of a DCV system ranges from $300 to $1,000 per room. A whole-house DCV system is typically more than $10,000.