The Cluster for Sustaniability in the Built Environemnt at the University of Maryland (CITY@UMD) plans to build environmental and climate chambers to study different ventilation strategies, indoor thermal comfort, and indoor/outdoor building science validation studies.
- Overall Chamber Dimension: The dimension of the chamber (length × width × height) is 22ft × 16ft × 15ft (6.7m × 4.9m × 4.6m).
- Climate Chamber: The Climate Chamber compartment occupies 30% of the chamber and has dimension of 6.6ft × 16ft × 15ft (2.0m × 4.9m × 4.6m).
- The Environmental Chamber: The Environmental Chamber is 15.4ft × 16ft × 15ft (4.7m × 4.9m × 4.6m) and occupies 70% of the chamber.
- Location of the Chambers: The chambers are located in a warehouse condition area and the ground level of the space is used for the installation of the sensors and the mezzanine is used for the installation of the HVAC systems.
Air Handling Units (AHUs): Each of the chamber compartments has separate AHUs that supplied the filtered and conditioned air, meaning at the same time the chambers can have different temperature setpoints.
- Air Change Hour (ACH): The airflow rate for the chamber is 1 ACH to 12 ACH. Also, it is required for the both of the chambers to operate with 0 – 100% of the outdoor air and meet the requirements of the indoor air temperature and humidity under the outdoor design conditions.
- Air Leakage: Max AHU leakage should be less than 5% of the flow supplied to the chamber at any time. The current need is 2-10 Pa to make sure that there is no infiltration to the chamber conditioned spaces.
- Setpoint Response Time: The maximum allowable response time for achieving a new set point and humidity is 10 minutes.
- Design Conditions: The design conditions to size the HVAC systems for the chamber are:
- Summer design conditions: T= 95°F (35°C) and RH = 60 %
- Winter design conditions: T = 19.4°F (-7°C) and RH = 60 %
- Operating Condition: The temperature and relative humidity inside of the chamber needs to vary between the lower and upper range specified in the following when the chamber uses 100% outdoor:
- Minimum temperature and relative humidity of the chamber are 68°F (20°C) and 40%, respectively.
- The maximum temperature and relative humidity of the chamber are 82.4°F (28°C) and 70%, respectively.
- Internal Loads: The maximum internal load of the chamber consists of 6 persons, 6 personal computers/laptops, lamps, measurement equipment. This will not exceed 2 kW.
Figure 1. Partitioning of the chamber into the Climate Chamber and Environmental Chamber
Figure 3. Two-dimensional cross section of the AHUs with the installed sensors
Figure 2. Description of the taller entry doors to the chambers
Figure 4. General overview of the chambers and components of the chambers with the location of the lab (3D view from NE)