#Ashrae 90.1 2016 table 5.5 code#
Only two states have an energy code less stringent than Standard 90.1-2007, so I did not dig deeper than the 2007 edition.)įigure 1: Slab-on-Grade Insulation Applications. (This information applies at least as far back as the 2007 edition of standard. This figure is adapted from a similar figure in the ASHRAE's 90.1 User's Guide. In hopes of offering some clarity, the figure below depicts acceptable and unacceptable slab-on-grade insulation applications. While ASHRAE's performance requirements for slab-on-grade insulation has shifted over time, the basics of the standard's permitted applications of slab-on-grade insulation have remained largely unchanged for the past several editions of Standard 90.1. In all climate zones, the horizontal insulation extending outside of the foundation shall be covered by pavement or by soil a minimum of 10 inches thick.
#Ashrae 90.1 2016 table 5.5 full#
Insulation installed outside the foundation wall shall extend form the top of the slab directly down for the full distance, or at least down to the bottom of the slab and then horizontally until the specified distance is achieved.Insulation installed inside the foundation wall shall extend downward from the top of the slab a minimum of the distance specified or to the top of the footing, whichever is less.Exception: For monolithic slab and footing, the insulation must extend only to the bottom of the footing or the distance specified, whichever is less.
Heat losses from heated slabs are greater than that of unheated slabs because the temperature is warmer. Heated slabs-on-grade will feature hot water pipes or coils embedded within or beneath the slab to provide space heating. Unheated slab-on-grade floor: a slab-on-grade floor that is not a heated slab-on-grade floor. Heated slab-on-grade floor: a slab-on-grade floor with a heating source either within or below it. Let's unpack the issue in the context of ANSI/ASHRAE/IES Standard 90.1 - Energy Standard for Buildings Except Low-Rise Residential Buildings.įirst, the standard defines two classes of slab-on-grade: Slab-on-Grade Insulation Requirements in ASHRAE Standard 90.1