... design 4. R22, R410a,R407c,R134a Heat pump heat exchangers are made of top quality titanium ... pipes using advance PVC plastics, with corrosion environmental protection.They are suited to ... R, stainless steelExcellent PVC plasticCompact design with high heat transfer ability.Suitable for R22, R134a, R410a,, ... 10.5kw Spa pool heat pump heat exchanger