A heat exchanger modular unit (100) configured to be assembled with like units to form a heat exchanger. Each modular unit includes an elongate conduit (101) and connection means (102) configured to enable the modular units to be assembled together. Each elongate conduit (101) includes at least one internal bore through which a heat transfer fluid is capable of flowing. In particular, the connection means is formed non-integrally with the conduit enabling different materials to be used for both components. The conduit and connection means are bonded together using suitable bonding techniques.
