Extek Energy Equipment (Zhejiang) Ltd. is a specialized manufacturer of heat exchangers including coaxial coils, new patented high efficiency shell & tube heat exchangers, indoor heat pump units with barrel type heat exchanger and titanium heat exchanger. Extek has successfully developed and manufactured coaxial coil heat exchangers used in water/ground source heat pump and heat pump water heater products. Extek was instrumental in the creation of the National Standards of