voogu moodustav vedelik, gaas või aur, substance, as a liquid or gas, that is capable of flowing and that changes its shape at a steady rate when acted upon by a force tending to change its shape, vedeliku ja gaasi ühisnimetus, heat transfer medium in a district heating and/or discrict cooling system, soojuskandur kaugkütte- ja/või kaugjahutussüsteemis