water to waste application

[marijka]

Все еще тепловые насосы,
WATER TO WATER HEAT PUMP REVERSIBLE ON THE REFRIGERANT CIRCUIT FOR INDOOR
INSTALLATION

И перечисление на заглавной странице:
Versatile for every application:
-terminal units and radiant panels
-for system with water to waste application or geothermal system
_Reduced energy consumption
_Water group supplied as standard

Я не понимаю (и не могу найти) water to waste

хелп, плиз...