Accession Number:

ADA158002

Title:

Condensation Potential in High Thermal Performance Walls. Hot, Humid Summer Climate.

Descriptive Note:

Forest Service research paper,

Corporate Author:

FOREST PRODUCTS LAB MADISON WI

Personal Author(s):

Report Date:

1985-07-01

Pagination or Media Count:

30.0

Abstract:

To observe actual moisture patterns and the potential for condensation due to long periods of air conditioning in a hot, humid climate, a test structure was constructed near Gulfport, Mississippi, for exposure of eight types of insulated wall panels at controlled indoor conditions and typical outdoor weather conditions. Panels were instrumented with moisture sensors and tested without Phase 1 and with Phase 2 penetrations electrical outlets in the indoor surface. There was no sustained condensation in any of the walls during either winter season. One type of high thermal performance wall had sustained condensation during both summers, but the wall dried out as the weather became cooler, and moisture content of framing never exceeded 17 percent. Low-permeance sheathing appeared to provide resistance to the buildup of moisture during summer in walls with high overall R values. Penetrating the walls with electrical outlets resulted in slightly higher moisture levels in all of the walls throughout the year. This paper should be useful to building designers, builders, and building code officials in establishing vapor retarder requirements for walls. Keywords Condensation, moisture control, vapor retarder, air leakage, wood-frame walls, foam sheathing.

Subject Categories:

  • Air Conditioning, Heating, Lighting and Ventilating
  • Structural Engineering and Building Technology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE