Investigation of Concrete Wall Systems for Reducing Heating and Cooling Requirements in Single Family Residences

The single family housing sector currently accounts for approximately 15% (US DOE 2002) of the total national energy consumption with the majority of the energy use associated with the HVAC system to provide comfort for the residents. In response to recent concern over the unpredictability of the energy supply and the pollution associated with its consumption, new methods are constantly being developed to improve the energy efficiency of homes. A variety of concrete wall systems including Multi-functional Precast Panel (MPP) systems and Insulating Concrete Form (ICF) systems have been proposed to not only improve the building envelope thermal performance but other important residential characteristics such as durability and disaster and fire resistance. MPPs consist of Precast Concrete Panels (PCPs) that incorporate structural elements, interior and exterior finishes, insulation, and even heating/cooling systems into a single manufactured building panel. The ICF system is a cast-in-place concrete panel system that does not offer the level of integration found in the MPP system but has become increasingly accepted in the building construction industry. This research evaluates the thermal performance benefits of concrete wall systems in detached, single family home applications. The thermal performance benefits of two MPP systems and an ICF system are analyzed within the context of a representative or prototypical home in the U.S. and are compared to two wood frame systems; one representing a typical configuration and the other an energy efficient configuration. A whole wall approach is used to incorporate the two and three dimensional conduction and transient characteristics of the entire wall assembly, including the clear wall and wall detail regions, into a whole building simulation of the prototypical house. The prototypical house heating and cooling energy consumption associated with each wall system is determined for six representative climates throughout the U.S. to evaluate the effect of various ambient conditions on the relative energy savings. For each wall system, the effect of thermal bridging on overall R value, the effect of thermal capacitance, and the role of infiltration on energy use are investigated. The results of the research include a comparison of the prototypical house energy savings associated with each of the wall systems; an assessment of the relative importance of the increased insulation, thermal mass, and improved air tightness on the overall energy load; and a comparison of the cost of ownership for the various wall systems. The results indicate that properly designed concrete wall systems can reduce annual heating and cooling costs. In addition, the results show that the most significant impacts of improved wall systems are, from greatest to least: infiltration reduction, improved insulation configuration, and thermal capacitance. Finally, the results show that while there are energy savings associated with concrete wall systems, economic justification of these systems must also rely on the other attractive features of concrete systems such as greater durability and disaster resistance.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Mechanical Engineering

Department dc:contributor.department

Mechanical Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2004

Author dc:creator

• Doebber, Ian Ross

Chair dc:contributor.committeechair

• Ellis, Michael W.

Committee members dc:contributor.committeemember

• Beliveau, Yvan J.
• Nelson, Douglas J.

• energy efficiency
• thermal mass
• heat conduction

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-10262004-214448

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/35499