Heat Requirements Estimation

Looking for a quick way to determine your heat requirements? The graph above provides a rough idea of the amount of BTUs required to heat rooms of different enclosure levels.

Note: As a rule of thumb, 1BTU per cubic foot will give you a 10 degree temperature rise. However, heating requirements are governed by the type of temporary enclosure that exists. For example, less heat is required for a tight enclosure while more is needed for loose enclosures.

Enclosure Description

Very Tight

Structural Enclosure: Windows, doors, and elevators installed, walls exits (not dry-walled) – no partitioning*

Tight

Structural Enclosure: Windows, doors, and elevators installed, walls exits (not dry-walled) – medium partitioning*

Fairly Tight

Structural Enclosure: Tight roof and completed walls without insulation, window and door enclosed with canvas or plastic – medium to heavy partitioning*

Fairly Loose

Structural Enclosure: Tight roof and nearly completed walls; door, window and other openings covered with plastic or canvas – medium partitioning*

Loose

Structural Enclosure: Tight roof and nearly completed walls; door, window and other openings covered with plastic or canvas – heavy partitioning*

Very Loose

Structural Enclosure: Tight roof, sheet plastic or canvas walls – space is clear of significant partitioning*

*When heat is supplied from the beginning of the heating season, or if a space is well heated, partitioning isn’t a vital factor.


The heat requirements calculator provides general guidelines and is based upon a temperature rise from 22º-72ºF. On-the-job experience is a factor in final estimates. A job log is helpful for comparison of the estimates and final requirements, and facilitates estimates at similar structures.

Frozen spaces require additional heating capacity to reach the target temperature. The amount of frost in a structure determines the additional heating capacity, which can be terminated when frost and water vapor are no longer factors.

Contact us with any questions you may have about the heat requirements calculator.