The present invention discloses a polyol resin composition containing a polyether polyol blend, a polyester polyol, and a hydrocarbon blowing agent. The polyether polyol blend has at least a diamine initiated polyol, a propylene oxide polyol, and a polyethylene terephthalate initiated polyol having a functionality of from 2.3 to 3.0. The polyester polyol is preferably a phthalic anhydride initiated polyester polyol. The blowing agent is a C4-C6 hydrocarbon. Also disclosed is a method of producing a polyurethane foam combining the above mentioned polyol resin and an isocyanate component.