A system including a heat exchanger with two or more channels is provided. The system includes means for one or more source channels and one or more load channels. The source channels and load channels are enclosed for containing and channeling a heat-bearing fluid through the heat exchanger. The source channels and load channels are integrated as components of complete source circuits and load circuits with the purpose of conveying the heat-bearing fluids between heat/cold loads and the heat exchanger. The system also includes means for providing thermal storage that may be used for sensible heat storage, latent heat storage, or a combination of sensible heat storage and latent heat storage. Within the system there are means for putting the source channels, load channels and thermal storage means in intimate thermal communication with one another for the purpose of exchanging heat in all flow-directions.