Is an ERV better than an HRV?


What is the difference between an HRV and an ERV?

The core in an HRV (Heat Recovery Ventilator) transfers heat from one air stream to the other. This is called sensible heat. The term ERV (Energy Recovery Ventilator) is usually used to describe a unit with an enthalpic core that transfers moisture as well as heat from one air stream to the other. This (moisture transfer) is called latent energy.

Is an ERV better than an HRV?

Not necessary,  in very cold climates such as in some areas of North America, an HRV could work better than an ERV. This is because the air inside the home during the winter months will be more humid than the outside air. An ERV would transfer the latent heat (humidity) from the exhaust air back into the incoming airstream. This could aggravate moisture problems and encourage the growth of mold and mildew.

Instead, if the indoor air is too dry (during the winter) for comfort, an ERV can help recovering the moisture and the latent energy.

Besides, in summer the ERV will supply to the home air which is cooler and drier than outside, reducing the work for the air conditioner, and energy savings for you. In fact, about 2/3 of the energy used by the air conditioner system is to remove moisture.


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