Jim Baird Posted July 10, 2016 Report Share Posted July 10, 2016 A flooring installer makes these good looking air supply grilles that match the material he installs. Does anyone here think that the design restricts air flow enough to affect equipment operation or performance? Which leads me to a further question. Are air supply grilles among pieces of equipment that are listed and tested for the use? Click to Enlarge 45.25 KB Click to Enlarge 52.48 KB Quote Link to comment Share on other sites More sharing options...
plummen Posted July 10, 2016 Report Share Posted July 10, 2016 Floor registers are designed to be regulated,If the buyer thinks theyre too restrictive or not restrictive enough they can always change them later. Quote Link to comment Share on other sites More sharing options...
kurt Posted July 11, 2016 Report Share Posted July 11, 2016 They absolutely restrict air flow, sometimes as much as 2/3's reduction. We tested them a few years back with a hood; they suck. They look good, that's it. Quote Link to comment Share on other sites More sharing options...
Marc Posted July 11, 2016 Report Share Posted July 11, 2016 I agree with Kurt. The component in a distribution duct that most affects the resultant air flow is the register. Small changes in register design can make big changes in air-flow rates. I would absolutely be writing that one up: Custom made ceiling/floor registers are installed. These registers ruin the results of any duct system calculations done to match air flow rates to heat loads in individual rooms. You should ask your AC contractor to replace these registers. Depending on the condition of the remainder of the duct system, your AC contractor might recommend the additional step of repeating manual J and manual D calculations to confirm proper duct system design. Marc Quote Link to comment Share on other sites More sharing options...
kurt Posted July 11, 2016 Report Share Posted July 11, 2016 Or.... "These custom registers drastically reduce air flow; the room may not heat or cool adequately. If that's the case, replace these registers with conventional models." Take a picture and have an arrow pointing at a register. Please don't write stuff like you wrote. Next thing, you'll be using words like "imbricated". You're one of my last hopes in this gig for a shot at making things move forward. Everyone thinks the opposite of the way the world's moved, and they're proud of it. You seem to pay attention. Write like it. Please. With sprinkles on top. In my entire career I've seen a Manual J about twice. Maybe 3 times. No one's going to do a Manual J for a home inspection. Put your hand over the register; if you can't tell if the air flow is sufficient, keep practicing until you can. When it's not, say so. It's just a house. It's not complicated. Quote Link to comment Share on other sites More sharing options...
Jim Baird Posted July 11, 2016 Author Report Share Posted July 11, 2016 Thanks for the replies, guys. So, to my second question. I suppose these tech manuals you reference will speak of register/grille flow rates or opening specs, or maybe reference again some standard re the product? Surely a manufacturer install spec would not go that far out a limb? I have never noticed anything stamped, such as you see on foundation vents to spec net free area. Quote Link to comment Share on other sites More sharing options...
Marc Posted July 11, 2016 Report Share Posted July 11, 2016 AFAIK, manufacturers attach specified 'air resistance' values to each of their register products. Now, I haven't completed a computer-based Manual D or J calc myself yet (I'm still stuck on cardboard calculators), but I suspect there is data entered into them that reflects the resistance properties of the register. Kurt is correct...again, on all counts. I just love it when I find there is still more to learn. Marc Quote Link to comment Share on other sites More sharing options...
Erby Posted July 12, 2016 Report Share Posted July 12, 2016 They don't blow well. If you don't like how well they blow. Replace them. Quote Link to comment Share on other sites More sharing options...
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