Embodiments of the present invention relate to polyurethane foams having high air flow while maintaining viscoelastic properties. In one embodiment, a reaction system for preparation of a viscoelastic polyurethane foam is provided. The reaction system comprises (a) a polyisocyanate component and (b) an isocyanate reactive component. The isocyanate reactive component comprises (i) from 35 to 74% by weight of the isocyanate reactive component of one or more propylene oxide rich (PO-rich) polyols having a combined number average equivalent weight from 200 to 500, (ii) from 24 to 50% by weight of the isocyanate reactive component of one or more ethylene oxide rich (EO-rich) polyols having a combined number average equivalent weight from 200 to 2,800, and (iii) from 2 to 10% by weight of the isocyanate reactive component of one or more butylene oxide rich (BO-rich) polyethers having a number average equivalent weight of 2,000 or more.