Life-cycle cost study of ground source heat pumps in hot humid climate zone

Ground source heat pump (GSHP) systems are gaining recognition as a cost effective and green heating, ventilating and air conditioning (HVAC) alternative in the United States. Still, this technology is not highly utilized due to factors such as high initial investment, lack of confidence and uncertainties in cost items. This study focuses on the reflection of the variations in cost items on the feasibility and life-cycle cost of a typical GSHP system. For this purpose, life-cycle costs were calculated for a typical GSHP system and cost data was gathered for several projects. Possible variations on cost variables are defined. Then, the effect of these variations on life cycle cost is analyzed on a comparative basis with a conventional system. It was concluded that the GSHP systems may not be economically favorable over a conventional HVAC systems without current incentives in hot and humid climate regions

Development of a hurricane-resistant roof-to-wall connection using high-performance fiber composites

Significant portion of losses in hurricanes occur due to a discontinuous load path and weak connections. The purpose of this study was to develop an innovative, efficient and non-intrusive roof-to-wall connection for wood-frame structures using high-performance fiber reinforced polymer (FRP) composite materials. The development of new connections was carried out at the component level tests. Initially the bond strength between FRP and wood interface was investigated. Subsequently, a progressive FRP tie development test was conducted and several alternatives were tested and the most feasible one was chosen. The new FRP tie was then tested in a full-scale wood-frame structure to assess the in-situ performance under simulated uplift forces. The results of full-scale tests were in close agreement with the results obtained at the component level. The FRP tie system offers an easy-to-apply, non-intrusive and rather stiff alternative to existing metal connectors for both new construction and existing structures