A heat exchanger comprising a mixture inflow unit into which a mixture of air and fuel is introduced, a burner for combusting the mixture introduced through the mixture inflow unit, a sensible-heat exchange unit that is disposed around the burner, a latent-heat exchange unit in which heat is exchanged between combustion gas having passed through the sensible-heat exchange unit and a heating medium, and a combustion gas discharge unit is provided.

A heat exchanger comprising a mixture inflow unit into which a mixture of air and fuel is introduced, a burner for combusting the mixture introduced through the mixture inflow unit, a heat exchange unit that is disposed around the burner, and a combustion gas discharge unit for discharging the combustion gas having passed through the heat exchange unit is provided.

A heat exchanger comprising a mixture inflow unit into which a mixture of air and fuel is introduced, a burner for combusting the mixture introduced through the mixture inflow unit, a heat exchange unit that is disposed around the burner, and a combustion gas discharge unit for discharging the combustion gas having passed through the heat exchange unit is provided.

A latent-heat exchanger comprising an upper heat exchange unit in which a plurality of circulating-heating-water heat exchange units having a circulating-heating-water flow channel formed therein and a lower heat exchange unit disposed on the lower side of the upper heat exchange unit, in which a plurality of direct-water heat exchange units having a direct-water flow channel formed therein is provided.

A latent-heat exchanger comprising an upper heat exchange unit in which a plurality of circulating-heating-water heat exchange units having a circulating-heating-water flow channel formed therein and a lower heat exchange unit disposed on the lower side of the upper heat exchange unit, in which a plurality of direct-water heat exchange units having a direct-water flow channel formed therein is provided.