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Energy Recovery Ventilator

Sponsored in part by:

Eco-Wise globe

Eco-Wise

110 W. Elizabeth
Austin, TX 78704
(512) 326-4474
(512) 326-4496 (Fax)

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ERV Contents:

CSI NUMBERS
DEFINITION
CONSIDERATIONS
COMMERCIAL STATUS
IMPLEMENTATION ISSUES
GUIDELINES

RESOURCES

CSI NUMBER

157 250
155 620

DEFINITION

An energy recovery ventilator (ERV) is a type of mechanical equipment that features a heat exchanger combined with a ventilation system for providing controlled ventilation into a building.

An energy recovery ventilator with humidity regulation incorporates a method to remove excess humidity or add humidity to the ventilating air that is being brought into a house.

CONSIDERATIONS

This type of equipment was introduced as "air-to-air" heat exchangers in the colder regions of the U.S., Canada, Europe, and Scandinavia over 10 years ago. In these areas, tightly-built modern houses were developing problems with indoor air quality and excessive humidity during the winter. The air-to-air heat exchanger brought in fresh outside air to combat these problems, and preheated it at the same time. These products are now called heat recovery ventilators or HRVs.

Generally, in the Austin climate, there is not a significant energy dollar savings from using this type of equipment since they are quite costly (approximately $1,000 plus installation). The winters are too mild and short and the units are not as effective in the cooling season. However, when the health value of having fresh air in a home is considered, this equipment can be worth considering, particularly if it's the type that also controls humidity.

If a house is constructed tighter than 0.5 air changes per hour, any pollutants generated in the home can accumulate and reduce the indoor air quality to unhealthful levels. If fresh outside air is brought in through an open window to alleviate this problem, this air may be excessively hot, cold or humidity-laden and require conditioning at added expense.

In the Austin region, cooling energy costs can exceed heating energy costs. Therefore, it is more appropriate to consider this equipment useful in recovering "energy" (energy recovery ventilator) not simply "heat" (heat recovery ventilator).

Commercial
Status		 Implementation
Issues
technology suppliers cost financing public regulatory
ERV
ERV With Humidity Regulation

Legend
green Satisfactory
yellow Satisfactory in most conditions
red Satisfactory in Limited Conditions
black Unsatisfactory or Difficult

COMMERCIAL STATUS

TECHNOLOGY:

The technology is well-developed for units that do not offer humidity regulation. There are far fewer choices in equipment that will provide humidity regulation of the incoming fresh air.

SUPPLIERS:

These products are available out of our area. Very few suppliers in Austin are aware of this type of equipment.

The prices will range from $500 to $1,700 for these units. The payback on energy savings alone is very long but health benefits should be considered.

IMPLEMENTATION ISSUES

FINANCING:

This equipment can easily tie into the HVAC system of a home. It enhances the quality of the home environment. This should not be a problem for lenders. It is unknown if appraisers will give additional value for this equipment.

PUBLIC ACCEPTANCE:

There is very little awareness of this type of equipment. When understood, it is generally regarded favorably by people interested in new energy efficient homes and indoor air quality.

REGULATORY:

None.

GUIDELINESERVs are available in wall mount or duct-connected models. This discussion will focus on duct connected models which can be used for ventilating an entire house.

  • 1.0 Best Applications for an ERV