Certified passive haus units reference temp

[sonicboom]

I was going through this list:

https://database.passivehouse.com/en/components/list/ventilation_small

 

Does anyone know what the reference temp is for the heat recovery percentage ?

Edited December 15, 2024 by sonicboom

[Mike]

It's in the certification criteria - https://database.passivehouse.com/en/components/#certification-methods-info

 

     The effective dry heat recovery efficiency [is measured with] with balanced mass flows at external temperatures of between – 15 and + 10°C and dry extract air (ca. 20 °C)

 

Presumably the worst reading is taken.

 

However Heat Recovery Efficiency, as the name suggests, only measures heat recovered. On that basis a unit with expensive-to-run fans can look better than one with highly efficient ones.

 

The Efficiency Ratio is the key figure that allows you to compare units like-for-like, taking into account the electricity used as well as the heat recovered.