REPLACEMENT OF THE EXISTING HVAC PLANT!!! 2

[tcihvacff1]

Hi Everybody!
I am working on a Offshore & onshore project wherein we need to replace the existing Hvac system with improved Equipment reliability & performance to provide reliable operation..
97 Hvac units(2000 Tons) were serving Substations (2 are onshore), Satellite Instrument house, Analyser room & CCR since 25 yrs..

My question is not how to replace the plant but I am more bothered about the Alternative cooling system...
Before commencing demolition activities the respective buildings shall be provided with stand alone Alternative Cooling by construction contractor for a cooling load equal to the existing capacity to prevent the sensitive electrical and
instrument panels housed inside the buildings from getting damaged.

Proposed Hvac Units & its capacity:
1. Ducted Split A/C - 30T (2Nos)
2. Ducted Split A/C - 9T (4Nos)
3. Ducted Split A/C - 47T (4Nos)
4. Ducted Split A/C - 16T (15Nos)
5. Ducted Split A/C - 14T (3Nos)
6. Ducted Split A/C - 22T (2Nos)
7. Ducted Split A/C - 24T (19Nos)
8. Air Cooled
Chillers - 102T (3Nos)
9. Wall mounted
Package A/C - 5T (14Nos)
10. Bottom Discharge
Package A/C - 8T (14Nos)
(Nominal capacity= 12T)
11. Package A/C - 12.5T (2Nos)
(Nominal capacity= 18T)

Please reflect your experience on this.......

 

[willard3]

What is your question? We certainly can't answer for your contractor.

 

[trashcanman]

Why are you shouting (All Caps)?

 

[MintJulep]

That approach would seem to require more operations, and thus provide more opportunity to disrupt or damage things.

Install the temporary equipment, which will require some level of demolition, or at least moving stuff around.

Commission temporary equipment.

Remove original equipment.

Install new equipment.

Commission new equipment.

Remove temporary equipment.

Restore anything done to allow installation of the temporary equipment.

 

[317069]

you want to replace 97 units with total capacity of 2000 tons capacity, but you are installing 82 units with total capacity of 1600 tons. what about 400 tons and 15 duct connections

 

[tcihvacff1]

actually total proposed requirement is 1580 tons only.... & previous was less than the proposed capacity...its my mistake that i have written it approx. as 2000 tons.
please help me regarding Alternative cooling...

Thanks....

 

[KiwiMace]

For sensitive equipment, where you don't have redundant plant, you should generally try to install the new equipment before the old equipment is decommissioned to minimise the time taken to effect the changeover. During the changeover, you provide portable cooling units, spot coolers and the like. The temp solution depends on the size of the load, but your sizes given above indicate that this type of equipment will probably be sufficient.

If it is a ductless split, you can probably change out the whole thing in less than a day, so the staging of new and old plant is not so important.

 

[tcihvacff1]

Thanks KiwiMace!
Ductable split A/cs are used in this project.....
i think as you said for sensitive areas we need to provide spot coolers before decommissioning....
As i am a beginner in this field i dont know much about spot coolers or similar equipments. I would appreciate if you share your knowledge about such kind of equipments...Thanx again!

 

[KiwiMace]

http://www.spot-coolers.com

 

[317069]

what bothers you with this equipments?