Construction of Out-take Flues

N the out-take flue depends, to a or round in cross section. It must be O great extent, the success or fail- constantly kept in mind that the ure of the ventilation system. straighter the flue, the less friction. This flue preferably should be square The cross sectional area should be maintained the entire length of the flue. For example : if the flue, at the start, were the proper size and were decreased in size going through the mow, the capacity would be correspondingly decreased. This flue should be constructed of matched boards, double thickness and insulated with paper. It is essential that this construction should be as near air tight as possible. If care is not taken on this point, then the efficiency will be correspondingly decreased. It is advisable to locate these foul air out-takes so that no point of barn will be more than thirty feet distant. This is the greatest distance where the out-take flue can be depended upon to draw efficiently. It is well to locate a sliding door near the ceiling practically the same size as the opening below, so that during the summer months when the barn becomes too warm or too damp, the warm, damp air can be released quickly. Of equal importance to the out-take is the cap or ventilator on the roof. STAR Steel Cupolas are Page One Hundred Sixty-six