The NAHB Research Center, Inc. and Warren Builders of Albertville, Alabama are working together to evaluate PATH technologies in two test homes. The 1,500 square foot, one-story houses are identical except for the inclusion of two PATH technologies: Ductwork within Conditioned Space and Mechanical Ventilation.
One home is a control home built in accordance with the builder's typical methods including HVAC ductwork located in the attic. In the second home, all HVAC equipment and ductwork is located within the conditioned space. Duct leakage tests, thermal comfort diagnostics, and performance modeling are being conducted by Research Center engineers at both sites. Installation costs and design considerations have been closely monitored to assess the first cost of both approaches.
Three different mechanical ventilation systems have been installed in the second home:
- Central Fan Integrated
- Multi-Port Supply
These systems represent a broad range of first costs for ventilation equipment. They are being evaluated for design considerations, installation costs, operating costs, and air exchange performance. System monitoring will also highlight performance issues, like added heating/cooling load, indoor relative humidity, and effectiveness of control systems.
The evaluations at Warren Builders are at varying stages of completion. The conditioned space duct analysis is the most complete evaluation and permits several conclusions to be drawn, although critical pieces of information such as the modeling results are not available yet.
The mechanical ventilation systems have been evaluated through the design and installation stages, but no performance data has been collected yet. Current findings include first costs for equipment and required installation labor, as well as design considerations that the builder faced.
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