Comments by "Junior Leong" (@IceyJunior) on "Ductwork sizing, calculation and design for efficiency - HVAC Basics + full worked example" video.

  1. Hi Paul, the duct loss graphs you showed is it plotted from the pressure loss equation for fully developed flows (also called the Darcy-Weisbach equation)? Also, in this case gravitational effects are not affect the air in the duct as the duct is horizontal. What if some part of the duct is vertical? If so will this change the way of calculation as shown in this video? Also, when using this equal friction method, are you assuming that the pressure loss per meter length is constant? Also, will you be showing the other 2 method as mentioned in the early part of the video?
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  2. Hi Paul or any other engineer in M&E building engineering line, I have a question to ask you all about changing of duct size. Say a 500 (w) x 400 (h) mm duct, and I wanna change the height of 400 mm to 250 mm. I used the hydraulic diameter equation to calculate for the new width. However, when I compare the answer to the "duct calculator". It doesn't match with my calculation. My calculation shows a new width of 2000 mm whereas the "duct calculator" shows 850 mm. What assumption/mistake or anything other related things did I not take into considerations?
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  3. Can you do another difficult example with grille/coil etc.?
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  4. Anyone know how to calculate minor loss for grille? What's the k value of grille?
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  5.  @EngineeringMindset  I dunno about others, but I certainly do.
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