The heat of dust-laden and humid air is most effectively utilized by heat exchangers composed of separate heat pipes having individual finning. Their advantages imply simple decontamination of the surface and easy condensate removal from it. Their design allows different geometrical sizes and heat transfer parameters to be realized using a single unified element, i.e. a heat pipe. In unified heat pipe exchangers the problem of reasonable arrangement of heat pipes in a bundle must be solved. Reasonable arrangement suggests desired heat-engineering parameters of the exchanger. In the present paper, a nomogram is proposed to solve the above problem. The operating conditions and heat pipe quality are considered in detail.