An ERV transfers a certain amount of moisture along with heat energy and is typically installed in climates that have longer cooling seasons. (Feature illustrations courtesy of Panasonic.)

Energy recovery ventilation systems are used frequently across the United States to ensure proper ventilation is achieved in homes and businesses. These systems use the conditioned air inside a structure to heat or cool the supply air. For example, in the winter, these systems transfer heat from the warm inside air that is being exhausted to the fresh cooler supply air. In the summer, the opposite occurs, as the inside air is used to cool the warmer supply air. The Department of Energy estimates that most energy recovery ventilation systems can recover about 70 to 80 percent of the energy in the exiting air and deliver that energy to the incoming air, thus reducing the cost of ventilation.

There are two types of energy recovery systems: heat recovery ventilators (HRV) and energy recovery ventilators (ERV). The main difference between the two systems is that an HRV only transfers heat, while an ERV transfers a certain amount of moisture along with heat energy. HRVs are typically installed in climates that have longer heating seasons, while ERVs are installed in those climates that have longer cooling seasons. ERVs and HRVs are profitable add-ons that can be used to effectively address customers’ ventilation needs, as well as improve contractors’ bottom lines.


Since the 1970s, the envelopes of homes have been tightened in order to reduce energy costs, resulting in less natural infiltration. Combine that with the fact that families in the United States are spending more time than ever indoors, where the Environmental Protection Agency (EPA) states the air is 7 to 10 times more polluted than the air outside, and the need for more ventilation becomes obvious.

“The EPA lists poor indoor air quality as the fourth-largest environmental threat to our country, while the American Lung Association states that asthma is the leading serious chronic illness in children in the United States,” said Ian Guttridge, training manager, Fantech, Sarasota, Fla. “Balanced ventilation via an HRV/ERV can improve the quality of the indoor air. Unfortunately, too few contractors understand HRVs/ERVs and therefore do not promote them.”

In 2008, it was estimated that around 25,000 homes in the United States had an ERV or HRV, which means there is a big market out there waiting to be tapped, said Jim Shelton, national sales manager, Panasonic Home & Environment Co., Palm Harbor, Fla. “Offering ERVs/HRVs should be profitable for the contractor. They are setting themselves apart from their competition as they become looked upon as an IAQ expert. This leads to more referrals and repeat service opportunities.”

There are benefits to installing ERVs/HRVs in every geographic location, but first, a contractor must determine the needs of the customer. If customers are building a tight home, a green home, or weatherizing an existing home, then they should be considering a proper ventilation strategy, said Shelton. “Remember, ‘Built tight and ventilate right.’ If the home is not tight, there is probably little need for an ERV or HRV.”

Approximately 25,000 homes in the United States have an ERV or HRV, which means there is a big market out there waiting to be tapped.


ERVs and HRVs are beneficial in just about any application, and contractors usually find they are quick and easy to install, which maximizes profit, said Guttridge. “Fantech IAQ products are designed to be installer friendly in that mounting points are integral and all hardware is supplied along with simple installation instructions. In addition, the external controls for the HRVs/ERVs are low voltage to a single connector panel on the outside of the units.

Fantech’s bestselling residential HRV is the VHR704R, which is a compact unit that provides a continuous or intermittent supply of fresh air into the home while exhausting an equal amount of stale air. Guttridge noted that the VHR704R will provide fresh air for a typical two-bedroom, two-bathroom home up to 1,500 square feet. “The unit can be installed with or without an existing duct system, but if duct- work is utilized, it should be sized properly in regard to airflow and pressure loss and sealed to minimize air loss through joints. Ductwork to and from the outside should be insulated.”

Panasonic’s bestselling ERV is the Whisper Comfort Spot ERV (FV-04VE1). “We refer to it as a ‘spot’ ERV because it is a small, stand-alone, ceiling-insert ERV,” said Shelton. “Whisper Comfort is very affordable, easy to install, extremely energy efficient, and does not require a drain line. The ceiling-mount installation provides easy access for routine maintenance, and existing ductwork does not matter, as ours is a stand-alone unit that requires new duct to be installed. Panasonic simplifies this, though, by offering a unique dual-chamber wall cap that makes it easy to terminate the ERV to the outside with only one wall penetration.”

As for maintenance, that’s pretty straightforward, too. Guttridge noted that the electrostatic filters on their units should be cleaned on the same schedule as the furnace and/or air conditioning filters, or every three months. In addition, the core should be removed and cleaned once a year, and the inside of the unit should be cleaned at this time as well. Annual servicing should take no more than 30 minutes, he added.

Panasonic recommends that its units be cleaned every two to three months. Customers will appreciate this easy maintenance, as well as the fresh air an ERV or HRV can provide, said Shelton. “With tighter homes, the need for fresh air and proper ventilation has increased. ERVs/HRVs control the source of fresh air to make sure that it enters the home from a clean and healthy source.”

Healthy air leads to happy customers, which is why contractors should consider offering ERVs and/or HRVs as part of their standard IAQ lineup.

Publication date:08/23/2010