Quanda effect

http://en.wikipedia.org/wiki/Coand%C4%83_effect

Thanks...my spelling was all wrong but your answer was right-on.

"used the term "quanda effect" in referance to air flow and or the lack of air flow creating pockets of hot air.."

Unless you have high velocity air flow in the cooling system I suspect your HVAC engineer is trying to impress you and/or giving you a snow job.

The correct spelling is, as the guy most probably was reffering to, "Coanda effect".

This is a fluid dynamics effect, best illustrated in the application of deflecting jet engines thrust flow, by placing a mobile cyllindrically-convex panel on the side towards which u want the jet to be bent.

It somehow attracts the gas jet (consequence of Dynamic pressure + Static pressure = constant / see Bernoulli) and makes it follow the convex contour.

Now u can use Coanda in searching the Internet for more.

Look up

Coanda effect. It is in Wikipedia and all over Google.

Ford used the effect to spray washer fluid on their windshields

I have no idea why he feeds you a bunch of crap.

I design HVAC systems for studios, server rooms, and the three most important issues are how much cooling is needed (size of unit), the circulation of air in the room, and how quiet they need to be. The taller the ceilings, the more circulation you will need.

you can use a smaller unit if circulation is better, rather than say, pumping a whole lot of cold air in the room, the unit shutting off, then the room heats up, and the process starts all over again.

Perhaps the most problems I have are in regards to the installation itself, which falls under bad work ethics, and poor design leading to lower efficiency than you ever thought possible. This has led me to do it myself, and now I provide those services for my clients. If you need assistance, contact me further, and definitely GET OTHER ESTIMATES !!!!

Hi,

I haven't heard that term in ages. Trane VAV manuals used it to describe the airflow patern discharged from a linear slot difuser. They also showed us that this created a one to one aspiration ratio. Every one CFM of air dicharged from the difuser mixed one cfm of room air due to as was stated earlier hi velocity creating a low pressure causing mixing of room air. Kind of a punch word for salesmen to show us they know more than us.

Excellent answer...thanks.

I've encountered that term also during our lecture on aerodynamics. I also thought the spelling was quanda. Anyway, coanda effect as discussed by our instructor refers to a particular movement of a fluid (air or water) on a concave structure. as illustrated by our instructor it may be called a spoon effect. Example, slowly pour water on the tip of a spoon's handle (on the side of the concave part) as the water flows down, it follows the shape of the concave part of the spoon. same as the movement of air on an airfoil.