Ground Source Heat Pump Sub-Slab Heat Exchange Loop Performance in a Cold Climate

Mittereder, N. ; Poerschke, A.

National Renewable Energy Laboratory (U.S.)

关键词: Buildings;    Residential Buildings;    Sub-Slab Heat Exchanger;    Trnsys Modeling;    Ground Source Heat Pump;   

DOI  :  10.2172/1111203
RP-ID  :  DOE/GO-102013-4295
RP-ID  :  AC36-08GO28308
RP-ID  :  1111203

美国|英语

来源: UNT Digital Library

【 摘 要 】

This report presents a cold-climate project that examines an alternative approach to ground source heat pump (GSHP) ground loop design. The innovative ground loop design is an attempt to reduce the installed cost of the ground loop heat exchange portion of the system by containing the entire ground loop within the excavated location beneath the basement slab. Prior to the installation and operation of the sub-slab heat exchanger, energy modeling using TRNSYS software and concurrent design efforts were performed to determine the size and orientation of the system. One key parameter in the design is the installation of the GSHP in a low-load home, which considerably reduces the needed capacity of the ground loop heat exchanger. This report analyzes data from two cooling seasons and one heating season. Upon completion of the monitoring phase, measurements revealed that the initial TRNSYS simulated horizontal sub-slab ground loop heat exchanger fluid temperatures and heat transfer rates differed from the measured values. To determine the cause of this discrepancy, an updated model was developed utilizing a new TRNSYS subroutine for simulating sub-slab heat exchangers. Measurements of fluid temperature, soil temperature, and heat transfer were used to validate the updated model.