The Range

In most buildings, heat recovery cuts the ventilation-related heating and cooling load by roughly 50 to 80 percent. Cold climates with high heating demand see the biggest absolute savings; mild climates see smaller but still worthwhile gains.

What Drives the Number

• Local climate and design temperatures
• Exchanger effectiveness (higher is better)
• How balanced the supply and exhaust airflows are
• Run time - savings compound over 8,760 hours a year

A Quick Example

A 10,000 m3/h stream at a 20 K difference with 70 percent effectiveness recovers about 46 kW of heating load. Over a heating season that is a large, billable reduction in gas or electricity use.

Bottom Line

Recovery rarely pays for itself on first cost alone; it pays back through operating savings, usually within a few seasons in heated buildings.