splitting data from a feed

Hi, I've got a feed that covers a number of devices that have specific energy usages and I'd like to split this feed into 3 separate channels so I can monitor the power usage. 

On the same circuit : 

The MHRV has a power signature of between 40w and 180w 

The thermodynamic tank has a usage between 600w and 800w when its working and upto 1.5 kw if its using the immersion heater on the anti-legionaire disinfect cycle.

The pump for the power shower is  about 700w.

MHRV runs 24/7, the thermodynamic is on a timer and has power from 7am to 11pm but doesn't run for all that time - typically about 4 hours generating all our hot water.

Any thoughts on how to do it? 

Thanks