Analysis of Above-Code (2009 IECC) Residential Energy Efficiency Measures in ONCOR Service Area

Abstract

The purpose of this report is to provide an analysis of residential energy efficiency and renewable measures that would exceed the 2009 edition of the International Energy Conservation Code (IECC) in the ONCOR service territory. This information is useful to homebuilders, utility demand side energy managers, homeowners and others who wish to construct buildings that exceed the minimum national energy code requirements. A total of 17 measures based on the energy savings above the base-case house were selected. These measures include Renewable Power Options, Heating Ventilation and Air Conditioning (HVAC), Fenestration, Envelope, Lighting and Domestic Hot Water (DHW) options. Individual measures were then categorized into four groups: 0 to 5%, 5 to 10%, and 10 to 15% and above 15% source energy savings above the base-case house. After categorizing, three example groups were formed combining the individual measures so that the combined source energy savings of the group is 15% above the base-case 2009 code-compliant house. The savings achieved by each group ranged from 15 to 28%. The photovoltaic options presented the most savings in the range of 12-42% for all base-case houses. The analysis was performed using an ESL simulation model based on the DOE-2.1e simulation of a 2009 IECC code-compliant, single-family residence. Two sets of simulations based on the choice of heating fuel type were considered: (a) an air-conditioned house with natural-gas heating/domestic water heating (i.e., gas-fired furnace for space heating and gas water heater for domestic water heating), and (b) an air-conditioned house with electric heating/domestic water heating (i.e., heat pump for space heating and electric water heater for domestic water heating). Version 3.03.02 of the Energy Systems Laboratory’s International Code Compliance Calculator (IC3) was used with the appropriate TMY2 weather files. Different counties in the ONCOR territory were grouped according to 2009 IECC Climate Zone; and finally, two zones—Climate Zone 2 and 3—were identified and analyzed.