I would start with a general text, such as Crocker & King "Piping Handbook". Do you have access to a good technical library - or are you far from such facilities?

In multi storey design, because of the heights, distances and pressures involved, it is not practical to solve the problems in the same way that one would design normal commercial buildings. So the whole project is divided into a series of smaller sections - each of which can be treated as a normal commercial building. But to provide heating, cooling, water, and so on to each of the smaller (secondary) plantrooms a major (primary) plantroom is required.

With 20 stories a primary plant room is usually provided in the basement, with an cooling tower and mechanical services plantroom at roof level. In some cases a third primary plant room is provided at say the 10th storey

dear johnp
thank you for your reply.Could you advise a goog document for design of secondry plantroom?

I have been out of this business for a few years. Going by memory I would look at the ASHRAE Guide, Woods Fan Engineering, or any of the texts in the air conditioning field.
Then I would approach your equipment vendors and ask them for some pictures and details of typical plant rooms of the size you have in mind.
There is no great magic to it. You have equipment - air handling, heating, boilers, heat exchangers, pumps and whatever. Start somewhere to lay these out in a logical way. You can do this on some sketch paper with each piece of equipment as a rectangle of some approximate size. I have even cut these out of cardboard, and then started to play with them to work out a layout.
Then look at access. How are you going to maintain the equipment? How much ventilation do you need? Have you enough natural ventilation, or do you need a fan?
Do you have oil, or coal, or gas that needs to be stored and handled? What are the Codes of practice that apply?
Then put red flags on any equipment, vessels and pipes  which is hot. What is the expansion? How much movement do you have to cater for? Put a red flag on every nozzle. What loads will the piping put on the nozzles? Can the equipment tolerate the thrusts, moments and shears?
Also look at height. How much vertical room do you need for ducts and piping. What would the elevation look like for your tallest equipment.
Just start somewhere with simple rough sketches. That will stimulate your mind, and before long you will find your plantroom requirements start calling out to you.
The same thing when you are working with an architect. Both of you need to take a guess. Usually the architect will try to squeeze you down in size and height. There is no magic book that will tell you the answers. You just have to list the equipment you will need, take a guess on the likely sizes (ask your Vendors for approximate dimensional information) and then allow extra. It is better to ask for too much space initially, than to go back later and ask for more.