Building Thermal and Material Sciences Laboratory
The main location of the Building Thermal and Material Sciences Laboratory (BTMSL) is 2404 LEEP2. However, some of its research set ups are located in other outside locations around the Engineering Complex and the University of Kansas’ West Campus. Areas in which research and development is carried out in this laboratory relate to building enclosure components for residential buildings, including experimental and modeling studies of advanced insulation systems, such as reflective insulation (i.e., radiant barriers and interior radiation control coatings) and thermally-enhanced insulation via the integration of phase change materials (PCMs). Non-building enclosure research includes the experimentation and modeling of airflow inside flexible heating, ventilating, and air conditioning (HVAC) ducts, experimentation and modeling of heat transfer across the insulated walls of refrigerated truck trailers, the study of deflection in mast arms of traffic signals, and the study of industrial manufacturers’ implementation of energy efficiency measures. The following facilities and equipment are found in BTMSL:
Test Houses Facility
This is a set-up consisting of two identical test houses of conventional residential construction with scaled down heating and cooling systems. The dimensions of the house are 1.83 m x 1.83 m x 1.22 m (6 ft x 6 ft x 4 ft). Both test houses are fully-instrumented to monitor and record space cooling and space heating energy consumption, indoor air and surface temperatures, indoor air relative humidity, outdoor surface temperatures, and wall heat transfer. One house is generally used as a control house, while the other is used as a retrofit house, where new technologies are tested. A weather station that measures and records outdoor air temperature and humidity, wind speed and direction, and total solar irradiation is also in place at this location. The houses are precision air conditioned and heated and are independently metered. No shades from trees, buildings, or other obstructions are allowed in this set up. To condition the indoor air of the test houses during cooling, a chilled water system was assembled where water is chilled down to 4.4 oC (40 oF) with a small immersion refrigerator. Pumps circulate the chilled water through a piping network and across fan-coil-units (FCUs) placed inside the houses. Precision electric resistance heaters are used the space heat the houses during winters.
Dynamic Wall Simulator
The simulator is a cubic box designed to hold six 1.22 m x 1.22 m (4 ft x 4 ft) wall panels. Heat sources, placed equidistant at the center of the simulator’s interior simulate solar loads and outdoor air temperatures. A refrigeration unit removes heat from within the simulator at a rapid pace when needed. Two 80 mm x 80 mm (3 in. x 3 in.) fans produce a uniform temperature distribution within the box. The output from the heat sources is varied and controlled by digital timers and potentiometers, programmed to simulate daily exposure to the sun. Using this configuration, the interior of the simulator represents the exterior of a typical building. Because the simulator is housed in an air-conditioned laboratory, the exterior of the simulator represents the interior conditioned space. The dynamic wall simulator is equipped to carry out three independent testing modes, which are:
- Rapid step change of the exterior temperature in heating mode to understand insulation behavior under heating conditions.
- Rapid step change of the exterior temperature in cooling mode to understand insulation behavior under cooling conditions.
- Steady-state test at constant temperature. In this test, heat transfer in the whole assembly is stabilized to steady-state conditions
Truck Trailer Simulators
Two refrigerated truck trailer simulators with a dimension of 1.22 m x 1.22 m x 1.22 m are used to test new generation insulation for the walls of refrigerated truck trailers. One test simulator uses standard, industry approved, trailer walls, while the other simulator’s walls are outfitted with new forms of insulation, which happen to be investigated, studied, or characterized. A closed loop system involving a chiller and two heat exchangers is used to provide refrigeration to the simulators. The simulators are equipped with instrumentation to measure and record air and surface temperatures and heat fluxes.
HVAC Flexible Duct Research Set Up
With this set up, a method and ready-to-use tables of pressure loss coefficients for flexible ducts as function of airflow rate, duct diameter, duct length, and bend angle are being determined. The set up was built to meet ASTM standards for air flow measurements inside air ducts. The instrumentation includes pitot tubes, orifice meters, manometers, and thermocouples. Simulation of airflow inside ducts is also carried out using FLUENT.
Differential Scanning Calorimeter (DSC)
A DSC is housed in the Building Thermal and Material Sciences Laboratory (BTMSL) is 1135 Learned Hall. The DSC is used to measure the apparent molar heat capacity of macromolecules as a function of temperature for the purpose of producing complete thermodynamic characterization of phase transitions, specifically in phase change materials for building applications. The information that can be obtained from this DSC includes heat capacity of molecules, enthalpy change, entropy change, and heat capacity change of molecules as a function of temperature induced phase transitions.