If the purpose is to trap the cool air between the hall, that will cost you more to partition, install another aircon and consumption. Doesn't look cost effective.

Not practical because there are holes in it and the cooler air still leak out ?

Maybe not 100% effective but perhaps able to conserve 30-40% compared to no partition right ?

Not very clear about your idea of installing a ceiling fan.

If the living hall, dinner hall and kitchen are all one after another in rectangular shape, where the ceiling fan should be installed ?

Hi, this looks nice. Where can I get this?

A curtain will be effective.

Any suggestion of a suitable curtain ? Maybe the track curtain is installed between the kitchen and dinning area. Sort of also using it to separate the kitchen fumes and smoke from entering the dinning and living area. But I haven't seen anybody did that to their kitchen.

You can look for "pvc divider" in online purchase website. Comes with rings to join them together.

Should be available in leong, alibaba, aliexpress or something.

Looks good but I supposed when you see the actually thing and knows it it made up of PVC, then you will say it's cheap stuff ! LOL.

why not use air curtain?
cheaper than Aircond, cheaper than partition.

For sure is the dining hall, kitchen you need to partition it to prevent smoke and oil.

Using string curtain as room divider :-