Recovering Energy from Class 2 Exhaust Air

The Problem

Providing a healthy environment must be the top priority for any air conditioning design. This can be difficult though, especially in spaces that generate less-than-ideal breathing conditions. Nail salons, health clubs, and bathrooms are just a few examples of spaces where processes or people taint the air with undesirable chemicals or odors. In these spaces, building designers are missing an opportunity to save valuable energy while providing healthy buildings.

ASHRAE 62.1 – 2019 designates air in these spaces as Class 2 air and stipulates that it must be exhausted. Fresh, but expensive to treat, outside air must be brought into the building to replace the exhaust. Here, designers are dropping the ball if they simply throw away the exhaust air. It contains valuable heat energy that should be recovered and used to reduce the energy needed to condition outside air.

The Solution

United CoolAir’s Alpha Aire utilizes two energy recovery devices to extract heat energy from the exhaust and pre-cool (in summer) and pre-heat (in winter) outside air before it reaches a coil. The unit design reduces the load on the cooling and heating coils to as little as 1/3rd that of a standard outside air unit. At a fraction of the operating cost, Alpha Aire delivers room-neutral (roughly 73° and 50% RH), fresh air to a building.

One common concern with Class 2 applications is whether the exhaust air will be transferred back into the building by way of the energy recovery wheel. United CoolAir utilizes a molecular sieve enthalpy wheel with a rated EATR of 0.5% or less. This means that less than one half of one percent of air leaving the building will be trapped in the wheel and recirculated into the space, a rate undetectable to humans and one far lower than the 10% allowed by ASHRAE 62.1 – 2019.
Designers should not hesitate to use all of the energy at their disposal. Alpha Aire gives them the opportunity to do just that. Call or click the link above to find out more.

Applications