ERVs and Mold?
High Quality Indoor Air: We love to create homes with great indoor environments - with systems easily controlled and maintained, to save energy and promote human health. An ERV is one of our best ventilation tools in this struggle.
An ERV is an Energy Recovery Ventilator. It’s designed to bring fresh air into your house, warm it up, manage its moisture, and deliver it to your living spaces to provide healthy air to those who live there. It’s a Balanced system, which means it exhausts the same volume of air to the outside as it brings in. It can be tied to a central air system, installed as a stand-alone solution, or decentralized to take up minimal space only where most needed.
The system passes the outgoing air across a transfer medium, which allows heat and moisture to be move from high-to-low concentrations - from warm outgoing air (in the winter) to the cold incoming stream, to warm it up. It does the same with humidity - humid air gives its moisture to drier air. So far so good.
A concern some folks have is that - here in New England - we’re bringing IN warm wet air in the summer and making problems for ourselves by fostering environments where mold can thrive. And that ERVs can make this problem worse. To a point, we agree - un-regulated introduction of extra humidity into our homes is a bad idea! Any ventilation system, without active cooling and/or dehumidification, runs the risk of bringing more hot air and more humidity. Instead, we consider the whole house, in its local climate, and we recommend mechanical cooling (air conditioning) by heat pumps, dehumidification as a stand-alone system when its warranted, AND ERVs to help us manage temperature and humidity throughout the year.
As the design and construction industry grows up and really starts to address the challenges of Building Science, we’re learning how to find the right balance in our mechanical systems. We’re always striving to achieve good indoor air quality AND energy savings, carbon reductions, comfort, and durability. This is one of the real values in careful design.
