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GSR Research



Low Temperature Psychrometric Chamber


     The low temperature psychrometric chamber artificially reproduces the temperature and relative humidity of various climates around the world, from tropical to continental, from dry desert to northern and polar tundra. The temperature can range from -40 to +130F (-40 to 55C) and the relative humidity from 10 to 95% R.H.



















This psychrometric chamber is used to experimentally study the behavior of systems and components under specific ambient conditions.  Primarily intended for testing heat pumps, refrigeration systems, and unitary equipment up to 20 tons (70 kW) of refrigerating capacity, the facility consists of two similar-size adjacent rooms of about 19 by 20 by 18 feet high. The large floor area can accommodate multiple set ups inside each room. A double panel sliding door (shown in figure here) is located next to a gantry crane, which is used to position the testing equipment inside the chamber.



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Water fouling test facility


    The water fouling test facility is designed to experimentally measure the heat transfer rate and hydraulic performance of plate heat exchangers (PHEs) under fouling conditions. The current set up replicates similar operating conditions as in the actual field of service. A variable-speed pump circulates refrigerant inside the testing PHEs. Refrigerant condenses at the ARI conditions of 105 to 110F Saturated Condensing Temperature, 85F Entering Water Temperature, and water flow of 3.0 GPM/ton.  The overall heating capacity is up to 37,000 Btu/hr (11 kW).

    The water fouling facility is currently used to determine the fouling resistance of water cooled brazed PHEs by using simulated cooling tower water. The simulated cooling tower water is prepared in a batch inside the conical tank shown in the figure.  Water is then pumped through a series of pipelines into the plate heat exchangers and it is possible to develop correlations of fouling resistance and pressure drop with the water quality.



Air Flow Wind Tunnel


    The Air Flow Wind Tunnel was designed for flexible configuration of HVAC system experiments.  The facility consists of an air loop with supply and return fans controlled by variable speed drives and a test section with temperature control maintained by cooling and reheat coils.  Refrigerant (water/water-glycol solution) is pumped to the coils from two, five hundred gallon, temperature controlled tanks.  A 2.5 tons (9 kW) water-cooled chiller provides the refrigeration capacity in a wide range of temperature from -25F to +130F (-32 to 55C). An air flow measurement station accommodates a range of elliptical flow nozzles ranging from one to ten inches in diameter. The test section is constructed of inch clear acrylic panels to allow viewing of the velocity streamlines from any direction. 

    The air flow wind tunnel is used for experimental heat transfer measurements under dry-, wet-, and frosting operating conditions. The facility allows simulating the defrosting cycles typical of air-source heat pump systems. The set up is currently used for heat transfer tests on microchannel heat exchangers.


Building Airflow and Contaminant Transport Laboratory


    This state-of-the-art facility, currently under development at OSU will consist of two instrumented, commercial scale air loops serving two zones connected by a stairwell.  A particle imaging velocimetry (PIV) system and gas sampling capabilities are planned for the facility.  The laboratory will be capable of simulating transport of contaminants released either in the building zones or in the building system.  Immediate plans for the facility include validation of transport and HVAC system component models, development of system response protocols and validation of new building automation and security technologies.

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Hybrid Ground Source Heat Pump Laboratory  


    This facility, which is currently under development, will be used to develop hybrid ground source control strategies and validate hybrid ground-source heap pump (HGSHP) models for simulation programs.  An HGSHP system consists of a ground-loop heat exchanger (GLHE) with a supplemental heat rejecter (e.g., cooling tower, fluid cooler, pond coil, etc.).  This system is advantageous for buildings where the cooling loads are larger than the heating loads.  The bore field can be sized based on the heating loads and supplemental heat rejecter would allow the system to meet the cooling loads. 


    The main advantage of this system is that it more closely balances the heat rejected and extracted over the course of a year.  Another added benefit is the possible decrease in first cost and operating cost compared to conventional ground source heat pump systems. 

Thermal Pile

In early September of 2013, we installed a test thermal pile in collaboration with Dr. Xiaoming Yang of the OSU School of Civil and Environmental Engineering.









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Building Heat Transfer Laboratory

    This experimental facility, which was designed and constructed specifically to measure cooling loads, has several key features. First, it consists of two separate buildings of differing thermal mass in order to demonstrate the ability of the cooling load procedures to correctly differentiate between thermally massive and thermally lightweight structures. The facility is well sealed to minimize the infiltration heat gain and has a high percentage of glazed surfaces in order to maximize solar heat gains. The facility can be configured with or without a suspended ceiling, blinds, carpet and furniture.

    The facility was constructed in an open field on the campus of Oklahoma State University. Temperatures, humidity, wind speed and solar radiation are just a few of the measurements logged every five minutes at a Mesonet weather station located within a half mile of the facility. The buildings' air handling systems are identical, constant volume systems that continuously adjust the deck temperature to maintain a constant room temperature. The ventilative flow rate and room inlet and outlet temperatures are the critical measurements required to control the system and calculate the space cooling load.

    These buildings were being used for validation of cooling load calculation procedures as part of ASHRAE 1117-RP.

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Medium-Scale Bridge Deck






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Laboratory Snow-Making Machine








    This is a refined version of a snow-making machine developed by former students Mike Longwill, Brad Schultz, and Devin Thompson for their senior capstone design project.  Their report may be found here.

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The Pond







    This three acre pond serves as a lower "boundary condition" for the medium-scale test bridge.  Several pond heat exchangers are being tested here also.

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Surface Heat Rejecters







    A sidewalk, two shallow ponds and a saturated "sand box", all with embedded tubing are being tested for application as supplemental heat rejecters for ground-source heat pump systems.  For some commercial buildings, the addition of a supplemental heat rejecter can decrease both the first cost and the operating cost compared to a standard ground-source heat pump system.  See Chiasson's thesis for more information.

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Guarded Hot Box






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Heat Pump Test Loop






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