Based on the ambient temperature above 0 ℃ for the whole year like Guangdong province, China, usually we will suggest you Wotech model WBC-3.8. This model together with 250L water tank can meet 3~4 people needs of shower in an apartment.(Water outlet 50℃) If you have two floors, we will suggest you use Wotech model WBC-4.5 together with 300L water tank.(Water outlet 50℃) For more information please contact us.
the Building Envelope