In Estonian language, PriiEnergia means free energy. We are a technology company in Tallinn Technology Park TEHNOPOL. We are active with developing technologies which enable to save energy, like various solar, geothermal, and wind energy solutions. The present orientation was commenced in 2005, when the predecessor of our company started to compile energy audits for soviet-time apartment blocks. This activity led to an idea to improve the inner climate of an apartment block. The idea culminated with constructing a unique ventilation system with heat recovery to an old 60-flat apartment house near Tallinn in 2010. At present, we offer a developed solution in cooperation with our partners in Baltic states. About at the same time, an idea of a heat exchanger which would be able to cool down effluent in residential buildings became real. Yearly amounts of sewerage heat loss are enormous, whereas at the moment, market offers very few effective solutions to the problem. The system we have developed helps to fill this gap. With the help of Tehnopol, we are introducing this product to European markets. The company is a member of Estonian Heat Pump Association.