Recommendations for 15% Above-Code Energy Efficiency Measures on Implementing Houston Amendments to Single-Family Buildings in Houston Texas

Abstract

This report presents detailed information about the analysis that was performed to calculate the energy saving potential for residential buildings in Houston. In this analysis the energy efficient measures were proposed by the building officials of the City of Houston. Along with the options proposed by the officials, additional measures were selected from the previously-conducted 15% above code energy analysis conducted by the Energy Systems Laboratory for residential houses across the State of Texas. A total of thirty measures were selected based on the energy savings above the base case. These measures were categorized into five groups: Renewable Power Options, Heating Ventilation and Air Conditioning (HVAC), Fenestration, Envelope and Lighting and Domestic Hot Water (DHW) options. The analysis was performed using a simulation model of an International Energy Conservation Code (IECC)-compliant, single family residence in Houston, Texas. Four sets of simulations were considered based on the choice of heating fuel type and thermostat setback: a) natural gas (i.e., gas-fired furnace for space heating, and gas water heater for domestic water heating) with thermostat setback, b) electricity (i.e., heat pump for space heating, and electric water heater for domestic water heating) with thermostat setback, c) natural gas (i.e., gas-fired furnace for space heating, and gas water heater for domestic water heating) without thermostat setback, and d) electricity (i.e., heat pump for space heating, and electric water heater for domestic water heating) without thermostat setback. Individual measures were then categorized into four groups: 2 to 5%, 5 to 10%, and 10 to 15% and above 15% energy savings above base case. Ten grouped measures were then simulated from combining individual measures from the four categories whose combined savings are more than 15% above the base case. The cost of implementation of the individual as well as grouped measures was also calculated along with a simple payback period. The photovoltaic options presented the maximum savings in the approximate range of 15-40% for all base-case houses. The solar thermal option for domestic water heating presented energy savings above 15-20% for all of the base-case houses.