FIRST STAGE On GlobalSpec

From Commercial Ground-Source Heat Pump Systems

FIRST STAGE

The project began with modifications to an existing 3-ton (10.6 kW) variable-speed air-to-air heat pump. The machine has an ARI 210/240 rating of SEER=15.2 (COP=4.5) and an HSPF=8.75 (COP=2.6) (ARI 1992). Table 1 lists the performance data at various conditions.

Table 1: Performance Data of Variable-Speed Air Heat Pump Before Modification to Ground-Source (TC 1990)

COOLING @ 80 /67 F (27 /19 C) EAT
	Low Speed	High Speed
Capacity @ 95 F	OAT	12.6 MBtuh	37.5 MBtuh
35 COAT	OAT	3.70 kW	11.0 kW
EER @ 95 F OAT	24.3	9.40
COP @ 35 F OAT	7.12	2.75
^[*] Capacities and COPs do not include defrost penalty.

HEATING @ 70 F (21 C) ^[*]
	Low Speed	High Speed
Capacity @ 47 F	OAT	11.8 MBtuh	34.6 MBtuh
8 C	OAT	3.46 kW	10.1 kW
@ 17 F	OAT	6.5 MBtuh	19.3 MBtuh
1.9 kW	5.7 kW
COP @ 47 F	(8 C)		3.66	3.06
@ 17 F	(-8 C)		2.24	1.92
^[*] Capacities and COPs do not include defrost penalty.

The heat pump was installed as recommended by the manufacturer and tested at a variety of indoor and outdoor air conditions. The unit operated between 3% and 7% below published performance.

The compressor and power electronics were removed from the outdoor coil and installed in a cabinet indoors. A nominal 48 MBtuh (14.1 kW) coaxial water-to-refrigerant coil replaced the outdoor coil, and a vented 24 MBtuh (7.0 kW) water-to-refrigerant coil was placed at the compressor discharge. These coils, the heating mode thermostatic expansion valve (TEV), and the reversing valve are also...

Interested in this book and others like it? Try EngineeringPro™ from Books24x7®

<< Previous Excerpt | View Book Details | Next Excerpt >>

Copyright American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. 1995 under license agreement with Books24x7

Products & Services

Condensers

Condensers are devices which accept a vapor stream and convert it to a liquid using heat transfer and/or compression.They are used in steam turbines for power plants, in cooling units for in-process fluids, and in air conditioning systems for buildings and automobiles.

Search by Specification | Learn more about Condensers

Refrigeration Compressors and Air Conditioning Compressors

Refrigeration compressors and air conditioning compressors provide air conditioning, heat pumping, and refrigeration for large-scale facilities and equipment. Refrigeration compressors are sometimes called refrigerant compressors.

Search by Specification | Learn more about Refrigeration Compressors and Air Conditioning Compressors | Refrigeration Compressors and Air Conditioning Compressors Insights

Cogeneration Equipment

Cogeneration equipment produces power and thermal energy from a common fuel source, generally one that is considered to be a waste product from another process.

Learn more about Cogeneration Equipment

HVAC Chillers

Heating, ventilation and air conditioning (HVAC) chillers are refrigeration systems that provide cooling for industrial and commercial applications. They use water, oils or other fluids as refrigerants.

Search by Specification | Learn more about HVAC Chillers | HVAC Chillers Insights

Refrigerant Recovery Machines

Refrigerant recovery machines are used to remove refrigerants from cooling equipment according to EPA standards. Technicians use these devices before maintaining or repairing air conditioners, freezers or refrigerators. The refrigerant is recovered into a tank for subsequent recycling or reuse.

Learn more about Refrigerant Recovery Machines

Topics of Interest

TEST RESULTS FIRST STAGE

TEST RESULTS FIRST STAGE Testing was performed in a psychrometric room. All temperatures were measured with 1000 ohm platinum RTDs. Airflow was measured with a 12-by 8-in. (30 by 20 cm) venturi.

A Variable-Speed Ground-Source Heat Pump

At the time this article was written, Stephen P. Kavanaugh and Joey K. Parker were associate professors in the mechanical engineering department at the University of Alabama, Tuscaloosa. Robert S.

Design and Operation of a Commercial Water-loop Heat Pump System with a Ground-loop Heat Exchanger

At the time this article was written, Bernard E. Woller was director of facilities and special projects at Buckeye Power, Inc., Columbus, OH. Reprinted from ASHRAE Transactions 1994, Vol. 100, Part...

Appendix B: Units and Conversions

These conversions are for those units most commonly encountered in cold-air distribution design. Additional information and conversions for other units are given in the ASHRAE publication, SI for...

Notation

List of Symbols and Units [1] A Heat transfer area (m 2) C P Specific heat capacity (kJ/kgK) COP p Coefficient of performance for a heat pump (-) COP r...