The Australian Institute of Refrigeration, Air Conditioning and Heating (AIRAH) has released the fourth edition of DA09 Air Conditioning Load Estimation and Psychrometrics.
Used to help estimate air conditioning peak loads and partial loads in any given space, DA09 is a fundamental component of AIRAH’s technical manual offering.
DA09 editor Vince Aherne, said DA09 explores the topic of building heating and cooling load estimation in minute detail.
He said explanations are provided for the psychrometrics of the fundamental air conditioning processes, which are needed to design systems that will provide specified indoor design conditions for a defined range of occupancies and climate profiles.
“Air conditioning load estimation is all about predicting and quantifying the peak heating and cooling loads for a building and facility,” Aherne said.
“An accurate load estimation is the first and most critical step in the design and construction supply chain for an air conditioning system. It affects equipment selection, system size and design. It is critical for system functionality, future service satisfaction and energy performance.
“Sometimes more art than science, load estimation aligns the demands of climate, building form and building function with the health, comfort and productivity of the occupants or the process.”
DA09 provides a range of information and design data that can be used in any load estimation calculation.
“The topic of building heating and cooling load estimation is explored in detail in this manual, and the psychrometrics of the fundamental air conditioning processes, which are needed to design systems that will provide specified indoor design conditions for a defined range of occupancies and climate profiles, are explained,” Aherne said.
“Although this is a load-estimation and not an air conditioning design manual, it does draw strong connections between the choices a building/system designer – or load estimator – makes and the magnitude of the cooling and heating loads.”
DA09 covers heat and moisture flow through building elements, solar and transmission loads, internal heat gains from people, lights and equipment, quantifying infiltration and outdoor ventilation impacts, and quantifying system effects.
The manual also explains air conditioning process psychrometrics including plotting air states and interpreting psychrometric data for air conditioning system design, selection, and operation criteria.
DA09 is also a source of data and default values for the estimation of internal and external loads on an air conditioning system.