power saving

The maximum power savings is to have all heaters disconnected. You have to decide what the minimum number of heaters is required to meet your needs. If you need the full 24 kw then there is nothing you can do.

As for your furnace if power saving is your intension then do the following :-

1 . Reduce all types of heat loss from furnace either by frequent opening of the door and heat loss due to leakage from door and rear.

2. Have proper temperature controllers to ensure that heaters are switched off properly to ensure that over heating of furnace is not effected any time which is a cause of loss of energy.

The energy consumed by your furnace will depend on power consumed which is proportional to voltage and current. When you change the connection from delta to star the power consumption reduces but it take more time to attain temperature thus in effect energy consumed will remain same. The only difference is the life of element will be more. If you run the furnace connection in delta till the furnace reach required set temperature and then maintain the temperature in star connection it may avoid over shooting of temperature after disconnection by the the supply to the elements by temperature controller at set point, which can save a little energy and smooth temperature maintenance curve . But it is worth in design of larger furnaces but not worth in small furnace of 24 Kw size.