The South African Institution of Mechanical Engineering Psychrometrics and Psychrometric Principles Workshop Duration - 1 Day : Time - 08h30 – 16h30 (Registration at 08h00) Manual, teas and lunch provided CPD Validation Number : SAIMechE-0735-12/16 This workshop will earn delegates 1 credit in Category 1 This workshop is suitable for SAIMechE Groups 1 & 2 SAIMechE Group Classification 0 = Non-technical, 1 = Candidate 2 = Professional 3a =Professional and 3b = Senior e.g., HR, Finance (including GCC) with < (including GCC) with < Appointment with > 15 Management with > 5 years experience 15 years experience years experience with 15 years experience specialist interest Contents Contents – Continued This workshop covers the full spectrum of the application of Part 3: Psychrometric Processes psychrometrics in air conditioning. This section considers many air conditioning processes to which an air stream may be subjected, along with their psychrometric Part 1: Air, and its Humidity representation. Air heating, and then the process of sensible plus The Course opens with a discussion explaining the apparent anomaly of latent cooling are well defined for Delegates. The concepts of 'ADP' moisture content: kg of moisture per kg of dry air, and how altitude and bypass factor, central to the popular "Loadest" cooling load implications affect the psychrometric chart. It progresses through a calculation programme are given attention. straight-forward calculation based on the heat capacity of water, and A complex calculation combining sensible and latent cooling plus then extends this same approach to consider a calculation based on a conversion from volume flow measurement to actual mass flow of known mass flow rate of air across a heater element. With this air, moving through the enthalpy calculations, broken down into established, the question is posed of why there is the need for the sensible and latent components, and culminating in the involved complexities of the psychrometric chart, if it is really "this easy". establishment of kilowatts severally of the sensible and latent The material answers its own question by reaching the conclusion that a refrigeration requirements, and mass flow moisture extraction by change in the latent heat of the humidity component adds a substantial the process. This part of the material is arranged to be compliant new dimension to the issue. It considers in fine detail the bearing of with the widely-used "Loadest" cooling load calculation Dalton's Law on atmospheric humidity, and proceeds to make plain the programme. concept of 'saturation' and the implications of the saturation curve on the Evaporative cooling and desiccant dehumidification are considered, psychrometric chart. along with practical discussion of such installations and the Wet and dry bulb air measurements are explained, as are the dry bulb psychrometrics of their various applications. Vapour humidification and moisture content (specific humidity) scales of the chart, these and practical precautions in its application receive attention. forming the basic 'x'-axis and 'y'-axis of the Chart. The wet bulb lines and Finally, the psychrometric concepts of the application of the then the relative humidity lines are discussed, with then the profound 'energy wheel' come under discussion. differences between specific and relative humidity are expounded in much detail. (It being the Author's contention that this is the singular most widely misunderstood issue in air conditioning). Part 1 concludes with explanations as to why high and low relative humidity often have to Click the below button for past event be corrected, for their opposite reasons, by application of one form or delegate comments on this workshop another of Air Conditioning. Part 2: Enthalpy, Density and the Sensible Heat Factor Ratio COMMENTS The approach followed by many chart-makers, such as CSIR, whereby the enthalpy scale is formatted as a perimeter scale which encompasses the Chart, is discussed, and is contrasted with Willis H Carrier's alternative of depending on enthalpy deviation lines. Specific volume is discussed, reinforced with a calculation based on specific volume and air mass flow rates. Click here for a registration form The mixing of flowing air streams is considered, and Delegates are taught how to establish the mixture point. Reasons underlying the need for the sensible heat factor ratio, and the plotting and transferring of the SHFR line are demonstrated. .