Outside Air System

An Outside Air System manages the introduction of fresh outdoor air into a building, promoting indoor air quality. This system typically includes components like outdoor air fans, dampers, and filters. Outside Air System to simulate its role in providing ventilation, controlling humidity, and optimizing indoor environmental conditions for occupant comfort and well-being.

Heat Exchanger

Heat Exchanger Type

Specify from None, Plate, or Rotary. Heat exchanger type affects the modelling of frost control options and supply air outlet temperature control. For rotary heat exchangers, the rotational speed varies to control frost formation or the supply air outlet temperature. For plate exchangers, an air bypass around the heat exchanger is used to obtain the desired effect.

Sizing

Economizer Control Type

Specify the Economizer Control Type:

Fixed Dry Bulb

Sets outdoor airflow rate to a minimum if outdoor air temperature exceeds a specified dry-bulb limit.

Differential Dry Bulb

Minimizes outdoor airflow when outdoor air dry-bulb temperature surpasses return air dry-bulb.

Fixed Enthalpy

Compares enthalpy limits, reducing outdoor airflow if outdoor enthalpy exceeds the specified limit.

Differential Enthalpy

Minimizes outdoor airflow if outdoor air enthalpy surpasses return air enthalpy.

Electronic Enthalpy

Calculates humidity ratio limit based on outdoor air dry-bulb temperature, reducing airflow if the actual humidity ratio exceeds the calculated limit.

Fixed Dew Point And Dry Bulb

Reduces outdoor airflow if either outdoor dewpoint or dry-bulb temperature exceeds specified high limits.

Differential Dry Bulb And Enthalpy

Enables control based on both Differential Dry Bulb and Differential Enthalpy strategies.

No Economizer

Disables economizer, keeping outdoor airflow at the minimum throughout the simulation. In all control types, user-entered limits for dry-bulb temperature, enthalpy, humidity ratio, and dewpoint are checked.

Demand-Controlled Ventilation

Specify if the air loop supports Demand-Controlled Ventilation (DCV), allowing variation of outdoor air based on the actual number of occupants in spaces.

Sizing Method

Specify the Sizing Method:

Autosize: Automatically determines the appropriate size based on specified parameters.

Manual: Requires manual input of sizing parameters according to specific requirements.

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