---
title: "Appendix C (Informative)"
slug: "appendix-c-1"
updated: 2022-06-28T12:57:16Z
published: 2022-06-28T12:57:16Z
canonical: "standards.resnet.us/appendix-c-1"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://standards.resnet.us/llms.txt
> Use this file to discover all available pages before exploring further.

# Appendix C (Informative)

General Guidelines for Determining Energy Conservation Measure (ECM) Service Lifetimes and Maintenance Fractions

| Improvement Category | ECM Life | Maint. Frac. |
| --- | --- | --- |
| Air Sealing, Ducts | 20 | 0 |
| Air Sealing, Envelope | 30 | 0 |
| Attic, Ventilation | 30 | 0 |
| Attic, Radiant Barrier | 30 | 0 |
| Color, Roof Shingles | 15 | 0 |
| Color, Wall Paint | 10 | 0 |
| HVAC, Replacement | 15 | 0 |
| Furnace, Replacement | 20 | 0 |
| Hot Water, Heat Pump | 15 | 0.009 |
| Hot Water, Heat Recovery | 15 | 0 |
| Hot Water, Pipe Insulation | 15 | 0 |
| Hot Water, Tank Wrap | 12 | 0 |
| Hot Water, Solar, Direct | 40 | 0.011 |
| Hot Water, Solar, ICS | 40 | 0.004 |
| Hot Water, Solar, Indirect | 40 | 0.011 |
| Hot Water, Standard System | 12 | 0 |
| Hot Water, Tankless, Gas | 12 | 0.024 |
| Insulation, Block Wall | 40 | 0 |
| Insulation, Ceiling | 40 | 0 |
| Insulation, Frame Wall | 40 | 0 |
| Lighting, High Efficiency | 5 | 0 |
| Pool Pump, High Efficiency | 15 | 0 |
| Refrigerator, Replacement | 15 | 0 |
| Showers, Low Flow | 15 | 0 |
| Window, Replacement | 40 | 0 |
| Window, Film Tinting | 15 | 0 |
| Window, Solar Screen | 15 | 0 |