The Center 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 ×
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
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
Setpoint Response Time: The maximum allowable
response time for achieving a new set point and humidity is 10
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%
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
Figure 2. Description of the taller entry doors to the
Figure 4. General overview of the chambers and components of
the chambers with the location of the lab (3D view from