A Residential Energy Efficiency Assessment

Grant # 96-04
Principal Investigator: Bill McAnally
Organization: Iowa Central Community College
Co-Principal Investigator: Ray Beets, Electronics Engineering Technology
Technical Area: Energy Efficiency

Background and Significance
Saving energy has diminished considerably in the minds of the general public since the “energy crisis” of the 1970’s. Suppliers of energy efficient technology, building contractors and energy companies are at a disadvantage in promoting energy efficient technology because they must overcome the objections of homeowners to its higher initial cost. That is a significant challenge unless consumers can be persuaded by credible data that shows the savings in the long run. Existing comparative data regarding the cost savings and desirability of energy efficient technology lacks credibility because it has been collected based on accelerated degradation. Consumers want to see results from real homes and in “real life” circumstances before they can be convinced to make such investments.

The significance to this issue lies in the future. Residential consumers have not been reducing their energy consumption to the same degree that large commercial and industrial users have. Residential consumers do not perceive the savings that these larger users do. As a result, when the next energy crisis occurs they will not be well-prepared.

To overcome consumer and contractor resistance and apathy, the return on investment from energy efficient technology has to be shown. Homeowners need information that will excite them about the savings they can achieve. Contractors also need data on building practices that enhance the efficiency and effectiveness of the technology and which maintain or improve air quality.

Objectives of the Continuation Project:
This project has several objectives. First, it will enhance existing data regarding energy efficiency and conservation by documenting, in a functioning residential setting, its economic value for Iowans. For completeness, the project will assess current energy efficient technology in an occupied residence over a long period of time. Additionally, it will document best building practices that enhance energy efficiency and provide an educational program to teach best building practices to persons entering the building trades workforce. Finally, the project will inform contractors about the benefits of, and technical skills for, energy conservation and provide useful information for utilities and local building officials.

Summary of Work:
Due to the Carpentry Program’s previous home projects which have successful in energy efficiency, the College has chosen it to construct two of its four new residence halls. The College requested and was granted a time extension for the project that will have it completed in June, 1999. Work on the residence halls has progressed satisfactorily and the home project should be in full swing by spring 1998.

Prior to beginning construction of this year’s home by the Carpentry Program, the PI and Co-PI identified the data and conditions they intend to monitor and what equipment would be needed. All the equipment that will be installed has been acquired. The temperature sensor for the grey water retrieval system has been installed. The radon monitor and the temperature and indoor humidity sensors were tested by Mr. Beets and his electronics class to make sure the monitors will generate data that will be useful. They are also examining building extra sensors themselves. Sensor installation was completed in late 1997. Blower door tests are being conducted to generate comparative data on existing homes. One test has been completed on a home built in the ‘80’s with some of the same technology being installed in this project house.

Throughout the project, the PI has documented the building practices being used by his class in the construction of the house and the installation of the energy efficient technology.

Additional blower door tests were undertaken on three other houses. One is a modular home built in the ‘70’s, a second a home built without the technology being installed in the Carpentry Program house and the third is a home built in the ‘80’s by the Carpentry Program.

The sensors were installed once the framing is at the appropriate stage. The desktop units were installed once the house was enclosed and could be secured. They were energized when it was sealed. The CO2 and radon monitors have been installed upon completion of the house. Baseline data collection was initiated when the house was completed. The baseline data was collected prior to the homeowner occupying the house. This provides data on how the homeowner affects the end energy usage.

The final stage of the project began when the home was occupied and monitoring begins. Daily measures were taken to develop average comparative data. Random measures were also be taken during selected weather conditions. Demographic profiles of the occupants of the Carpentry Program house and the others measured were developed for comparison purposes.