Static Regain Method

[harsen]

Can anybody plz explain the static regain method for the duct design , If i can get any link or pdf i will be thankful to us

To Site moderator : Sir - Actually i am a junior engineer looking for career improvement so i try to study more points plz dont hesitate or think mistakenly that i am looking on same points.
Still i dont know to send a private message, i send through this

harsen

[Brian_UK]

Can anybody plz explain the static regain method for the duct design , If i can get any link or pdf i will be thankful to us

To Site moderator : Sir - Actually i am a junior engineer looking for career improvement so i try to study more points plz dont hesitate or think mistakenly that i am looking on same points.
Still i dont know to send a private message, i send through this

harsen

Harsen, we don't mind helping you but remember that this forum is primarily about refrigeration. Ductwork design is a separate field of study.

anyway...

One link for you.
http://www.air-conditioner-selection...er-sizing.html

although this one is better...
http://www.acr-news.com/news/news.asp?id=708

[Toosh]

Can anybody plz explain the static regain method for the duct design , If i can get any link or pdf i will be thankful to us

To Site moderator : Sir - Actually i am a junior engineer looking for career improvement so i try to study more points plz dont hesitate or think mistakenly that i am looking on same points.
Still i dont know to send a private message, i send through this

harsen

Here read this it don`t take a rocket scientist to GOOGLE something


http://ateam.lbl.gov/Design-Guide/DG...ingmethods.htm


Norm

[Magoo]

Static regain is the simplist design, generally known trunk duct design. You have a big ars## supply duct and the fan maintains a constant static pressure and you regulate each take-off.
magoo

[Brian_UK]

Static regain is the simplist design, generally known trunk duct design. You have a big ars## supply duct and the fan maintains a constant static pressure and you regulate each take-off.
magoo

Doesn't quite help with his question.

How do you regulate in your example?

[Magoo]

Hi Brian
Trunk duct design/ static regain is very popular with open plan offices, factories, large chillers and freezer stores, basically the trunk duct is selected for minimal duct velocity, and each take-off or outlet supply is regulated at take-off point with a damper. If application is open plan well each outlet is regulated for design air flow, whether a single supply or a multi-supply, you rush around with a diffuser hood and check each supply and regulate dampers. If variable supply diffusers then you need to allow for max flow per branch take-off and apply static supply pressure regulation for fan speed control, and split coils for cooling options if DX, or if other cooling as in air-conditioning the regulating water valve will regulate.
For example an open plan office as per a high rise bldg, the centre core areas are fixed flow, the problem starts when tennant installs individual offices, another example is a large coldstore, and a large supply duct runs down centre of space and a liniar slot diffuser/ regulator is fitted to give even airflow.
hoe this explains Magoo

[Brian_UK]

I understand all about the balancing of an air system but his question was about static regain not balancing dampers.

Designing a system with good static regain reduces the need for extensive dampering and can, in fact, reduce the number of dampers required.

[Magoo]

Static regain, to quote the Carrier design manual: Air distribution.
"The basic principle of the static regain method is to desighn a duct run so that the increase in static pressure ( regain due to reduction in velocity ) at each branch or terminal just offsets the friction loss in the succeeding section of duct. The static pressure is then the same before each terminal and at each branch. "

magoo