Design of Fume Extraction System

Establish where it is now, and where you want to be.

Get room size,

air exchange

And talk to a HVAC, they will need to go on a site visit....... that would be a good start.

What did you learn in school?

If all you learned was to ask others to do your work for you, you should have failed.

Do you know: How to Search the Internet - Hannon Library to gather information?

That should be your first goal. READ the above, don't ask some strangers to do your research for you.

You might start by searching for "design of fume extraction systems".

Do your own work!

Your first question about diaphragm pumps was bad enough. This is even worse. You are totally helpless!

I have already searched a lot and have enough research material. The purpose of posting my problem here is get some answers form experienced persons, nothing else

I don't want to indulge myself in any kind of discussion regarding someone's intellectual level

Neither do I want to discuss intellectual levels.

That's obvious from: "Please tell me very basic and easy design steps for industrial local exhaust ventilation design."

Consult local codes and regulations and design a system that will extract the required volume of air from the room in the specified time.

why do I see a vacuum or negative pressure problem in the yet to be designed room?

Yep! I had to design a vent system for a boiling sulphuric etch. When the door was closed , to the room, there was no air flow so i lit up a cigar and slowly opened the door till i had the proper flow of the smoke, was it to code, i doubt it, but as i had to do the test with mask and rubber protection it was safe enough for me.

Looking at the detail there is our safety guy, in the background, holding a flyswatter.

but was the cigar enjoyable? stay on topic!

First step would be to contact the local agency that covers environmental issues to see what you can and can not exhaust out. Any calculations for air turn over for fan size would depend on whether it needs to be cleaned up before it's exhausted outside. Any device to clean it up needs to be addressed. As it may retard air flow.

not to mention air changes per hour/day

Yes, codes(OSHA, electrical, building, etc.) are a good source to start. In a lot of cases, and I suspect this is one(having gone through a paint "dispensing" room), will give the requirements for venting and air flow. Other than that, electrical code will likely require all explosion proof fittings and fixtures. Building code will give you required fire ratings for the room as well.

If you are handling thinners fumes make sure all appliances and electrical installations are flameproof to the applicable Exe standards (or similar) and that the premises comply with the codes for hazardous areas.

I would guess you need something between this:

And this...

Just make sure it is a brushless motor!

if you're in southern California just call the AQMD, they'll have guidelines and restrictions a mile long to vent volatile compounds into the environment