Field monitoring and evaluation of a residential gas-engine-driven heat pump: Volume 2, Heating season

Abstract

PrefaceThe Federal government is the largest single energy consumer in the United States; consumption approaches 1.5 quads/year of energy (1' quad = lo1' Btu) at a cost valued at nearly $10 billion annually. The U.S. Department of Energy (DOE) Federal Energy Management Program (FEMP) supports efforts to reduce energy use and associated expenses in the Federal sector. One such effort, the New Technology Demonstration Program (NTDP), seeks to evaluate new energy-saving U.S. technologies and secure their more timely adoption by the U.S. government.Pacific Northwest Laboratory (PNL)'") is one of four DOE national multiprogram laboratories that participate in the NTDP by providing technical expertise and equipment to evaluate new, energy-saving technologies being studied and evaluated under that program.This two-volume report describes a field evaluation that PNL conducted for DOE/FEMP and the U.S. Department of Defense (DoD) Strategic Environmental Research and Development Program (SERDP) to examine the performance of a candidate energy-saving technology-a gas-engine-driven heat pump. The unit was installed at a single residence at Fort Sam Houston, a U.S. Army base in San Antonio, Texas, and the performance was monitored under the NTDP. Participating in this effort under a Cooperative Research and Development Agreement (CRADA) were York International, the heat pump manufacturer; Gas Research Institute (GRI), the technology developer; City Public Service of San Antonio, the local utility; American Gas Cooling Center (AGCC); Fort Sam Houston; and PNL. The purpose of the Fort Sam Houston/Triathlon demonstration is to evaluate the performance and cost-effectiveness of the Triathlon gas heat pump (GHP) in the Federal sector. This is done by measuring the performance of the candidate unit and comparing it to the measured performance of conventional heating, ventilating, and air-conditioning (HVAC) systems currently in the residences at the base. The energy consumption, thermal measurements, and maintenance records will be primary elements in the life-cycle cost analysis'of potential savings from the candidate unit.The NTDP project at Fort Sam Houston (San Antonio, Texas) features a 3-ton gas-enginedriven heat pump. A single-cylinder, four-stroke, 5-hp engine fueled by natural gas drives the heat pump's compressor. A distinctive feature of the technology is an inherent load-matching capability. The heat pump can vary engine speed and blower fan speed, and thereby . dynamically control capacity to balance with thermal loads. This balance minimizes the need for cycling and reduces the associated thermal losses, fluctuations in room temperature and humidity, and equipment wear. The unit produces added heating capacity and improved supply-air temperatures through engine-waste heat recovery. The Triathlon GHP is manufactured by York International.. Three test houses at the Fort were used for the field comparison of the Triathlon against conventional residential HVAC systems. The houses were chosen to have identical structur...

Gas Engine-Driven Heat Pumps for Small-Scale Applications: State-of-the-Art and Future Perspectives

“…Additionally, for residential application, the results of the field tests for small-scale units are satisfactory and in agreement with those declared by the manufacturer (see [98,99]).…”

“…At Pacific Northwest Laboratory, under the supervision of Battelle Memorial Institute and with the funding support of the USA Department of Energy, a GEHP was tested in cooling [98] and heating modes [99]. The reports showed the performance and costeffectiveness of a GEHP unit (Triathlon) produced by a USA company (York).…”

“…The field tests on GEHP using an indirect heat recovery system have been conducted in buildings of different sectors, such as office [88,94,96,145,162], fitness centre [145], museum [145], dining hall/restaurant [145,162], residential [98,99,150], university [122,123], commercial [189], swimming pool [85], university laboratory [175,176], elementary and junior high school [164] and retirement community building [193]. The unit analysed in [193] is also equipped with an electric generator.…”

“…Heating-direct recovery mode [122,123,150,193] Heating-indirect recovery mode [88,94,96,99,145,162,164,176] Cooling [94,98,122,123,145,150,162,164,175,189] Table 5. Field tests: heat pump source and sink.…”

“…Air-to-air [88,94,96,98,99,145,150,164,189] Air-to-water [85,122,123,162,175,176] Intense experimental activities have been carried out by many researchers all over the world through the analysis of GEHP units in laboratories, aiming to evaluate, by modifying different parameters, the performance, mainly at stationary conditions, though some studies also focused their attention on transient [85,105,119,137,144,157] conditions. In other cases, an investigation of GEHP performance reproducing daily heating and cooling loads has been considered [109][110][111].…”