Mechanical Insulation Design Guide - Design Objectives

by the National Mechanical Insulation Committee (NMIC)

Last updated: 07-26-2011

Estimate Time to Freezing for Water in an Insulated Pipe

Reference: 2009 ASHRAE HoF, Chapter 23, Equation 1 (pg 23.4)

This calculator estimates the time for a long, water-filled pipe or tube (with no flow) to reach the freezing temperature.

The calculation ignores the thermal resistance of the air film, and the thermal resistance and capacitance of the pipe or tube wall.

The latent heat of fusion of water is not considered in this calculation.

NA = Not Available. Insulation dimensions are based on ASTM C 585-09 and assume single layer installation. Some sizes and thicknesses are extrapolated.Some sizes listed may not be commercially available and some materials are available in sizes and thicknesses not listed.

Note: Calculator does not screen for material temperature limitations - Use caution.

Input Information
1. Initial Temperature of Water in Pipe, °F   
2. Ambient Temperature, °F
3. Select Pipe Sizes or Tubing Sizes
4. Select Nominal Pipe or Tubing Size
5. Select Insulation Thickness
6. Select Insulation Material