... metal water heat exchanger, which resists the eerosion from chlorine in the water, creates a longer lifespan;2) Economical and ... controller;5) Safety: water and electricity are insulated, no open fire, no creepage;6) Quiet: using the high-efficiency, low ... 7) High technology heat exchangers8) Safety: Protected from running in bad running circumstances, such as water temperature, compressor exhaust ...