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Commissioning process for an air handling unit in a small house!
January 18, 2018

Commissioning process for an air handling unit in a small house!

In small homes, ventilation unit is compact and it can be installed above the kitchen hood. And has a fewer settings and operation functions: the fans can operate in three speeds: away (low airflow and no one home), home (normal airflow) and boost (high airflow used for cooking, sauna and other activities).

To set the airflows

A qualified person should set the ventilation unit’s and the ventilation equipment’s airflows using appropriate measurement equipment. As an initial value for ventilation planning, you can use the ventilation value 0.5 times the volume of the building per hour + 6 l/s supply air per person, when the unit is operating in the Home mode. (Initial values can vary in different countries.)

As guidelines in the Away fan mode, you can use 0.9 x the airflow rate in the Home mode for the extract air fan and 0.7 x the airflow rate in the Home mode for the extract air fan. Scope for boosting should be provided in accordance with regulations that apply in the relevant country. All the fan modes must be present so that the ventilation unit will operate correctly. Fill in your entered settings in the commissioning report.


Decide which functions you want to be able to use from the main menu of an air handling unit. You can also enter settings that affect the ventilation system’s operation while you commission or service the unit.

In the commissioning form, you can find the factory settings and write down setting values for operating the air handling unit such as:

  • temperature supply air (ºC),
  • fan speeds for different modes (away, home, boost, cool off, refresh, heating), and fan speeds for supply and extract air fans for different modes,
  • negative pressure compensation, service reminder, summer cooling, heating, filter guard, fireplace switch function, boost, etc.,
  • settings based on project planning values and setting values for supply and extract air for different setting scenarios.

Important to remember for kitchen hoods as air handling unit

  • The supply airflow must be 5-10 % lower than the extract airflow.
  • Remember to explain the use of the item of optional equipment and how to service it to the user/caretaker!
  • Write down the data on the ventilation unit identification plate for reference when the need arises to contact a service company.

Read more about commissioning in HVAC: