Turndown

Turndown, or turn-down, is a term used in several fields to describe a reduction or adjustment from a higher level, and is most commonly encountered in hospitality and mechanical engineering contexts.

In hospitality, turndown service is a nightly housekeeping routine performed in some hotels to prepare a room for the guest’s evening or nighttime experience. Staff typically tidy the room, replace used towels, restock toiletries, lower the bedding by turning down the top sheet and duvet, and sometimes dim lights or close curtains. Turndown service is designed to enhance comfort and convenience, and may be offered as an optional amenity in addition to regular housekeeping.

In engineering and industrial settings, turndown describes a device’s ability to operate across a range of outputs, particularly at reduced levels. The term is often expressed as the turndown ratio, which is the maximum controllable output divided by the minimum controllable output. A higher turndown ratio indicates greater flexibility for operating efficiently at low load. This concept applies to burners and boilers, compressors, pumps, and other systems that require modulation to match varying demand while preserving efficiency and emissions targets.

In general usage, turndown can also refer to the act of turning something down or declining an offer or request, though this sense is less technical and more contextual. The word derives from the combination of “turn” and “down,” and spelling variations include turn-down or turndown depending on style guidelines.