Barcol-Air Chilled Ceiling BCC:
The BCC is a standard solution, which covers 80% of all applications.
The system consists of:
- Metal ceiling panels (manufactured by other)
- Heat Conduction Rails (HCR) / Bonding
- Copper tubing
- Acoustic blankets or fleece (optional)
- Flexible hoses
The BCC system is highly versatile. As each building differs in size, location, usage, cooling-heating demands, etc.,
the BCC system can be configured to meet the toughest demands, while still ensuring the highest possible thermal comfort
for a high quality indoor environment.
Basic System Design
 Cross-section with standard panel |
 Cross-section with alternative panel |
The BCC system can be applied with a large variety of ceiling panels (preferably metal) and is not limited
to a specific ceiling manufacturer. The design cooling/heating capacity is defined by the total number of active ceiling panels
installed (typically 60-70% of the ceiling area), the width of the HCRs (2 1/2" [63.5mm] or 3 1/2" [88.9mm]), the spacing of the
HCRs (typically 6" [152.4mm]) and the design temperatures of the supply water (typical range cooling; 55°F-65°F [13°C-18°C], heating; 86°F-100°F [30°C-38°C]).
The active panels can be fitted with sprinkler heads, smoke detectors, spotlights, etc. on site, or the panels can be delivered with precut openings. Larger openings, as for diffusers, etc. should be precut by the ceiling manufacturer.
A typical configuration for conventional ceiling systems (2'x2' or 2'x4', [600x600mm or 600x1200mm]) consists of 4-10 active panels, which are connected
in series with flexible hoses. The hoses are fitted with push-on couplings, which allow a very quick and simple installation of the system. The active
rows are then connected to the water circuit in parallel. A control valve in the return line sets the volume flow rate accordingly from 0-100%, depending
on the capacity required. The system poses no restrictions to the size of the control zone. The control strategy can range from individual room-by-room
controllers to a completely automated Building Management System.
Basic System Function
Cooling Mode:
As the control valve opens, chilled water starts circulating in the copper tubing and removes the heat stored in the ceiling (panel, HCR, copper) by means of
conduction. As a result the surface temperature of the ceiling decreases, which immediately starts the process of radiation exchange from the warmer objects
(people, computers, etc.) in the room to the cooler surface of the ceiling. Due to the temperature difference of the room air in the boundary layer below the
ceiling and the surface temperature of the ceiling, natural convection is generated, which increases the resulting cooling capacity of the system. Natural
convection is based on the buoyancy of air, which varies according to its temperature (cool air sinks, warm air rises). The air velocity which results from
natural convection is normally well below the threshold of draft occurrence in the occupied zone. On average, 70% of the cooling capacity is based on radiation
and 30% on convection. Heat, which is absorbed by the ceiling, is removed from the room by the chilled water (conduction). The BCC system is generally designed
for a temperature differential of 4°F [˜2°C] between the supply and return water temperatures.
The room temperature decreases until the set point of the thermostat is achieved. To prevent the room temperature from sinking further, the control valve starts
closing, reducing the volume flow rate through the ceiling and therefore reducing the capacity of the system until steady state conditions are achieved. Due to
a special bonding technique, which enables very high heat transfer rates, response times to changing room conditions (in- decreased heat loads) are virtually
only dependant on the response time of the control system.
The Barcol-Air Radiant Cooling Video (Home-page) shows the function of the BCC ceiling with animated images, as well as real-time infrared images, which illustrate how quick a chilled ceiling reacts, once the cooling valve opens.
Heating Mode:
Heating with the BCC system functions in the same manner as cooling, with opposite signs. The natural convection is reduced and the primary mode of heat transfer
is by radiation. The supply water temperatures are much lower than heating water used in conventional wall mounted radiators. The system is typically laid out for
temperatures ranging from 86°F-104°F [30°C-40°C],. The resulting heating capacity is equivalent to radiators operated at much higher temperatures, due to the
larger transfer surface available with the ceiling. The lower supply water temperatures offer significant energy saving potential, as well as a much higher thermal
comfort, due to a uniform heat distribution throughout the room. In applications with large glass surfaces along the perimeter, a separate heating circuit
(1-2 panels wide) operated at higher temperatures can compensate skin losses, thus allowing the building core zone to be operated at optimal conditions.
The Components
Ceiling panels:
Ceiling panels are available in a large range of sizes and patterns. Standard panel sizes are 2'x2' or 2'x4'. Lengths vary from 1ft to 12ft (size can vary depending
on manufacturer). The panel thickness is typically 22-24 gauge for steel, and 18-20 gauge for aluminum panels. The weight as installed varies from 1lb/ft2 to 2lb/ft2
(excl. acoustic blanket). The panels are fitted with a rugged powder coating, available in a large variety of colors. Specific details can be supplied by ceiling manufacturers.
Calibrated Copper Tubing:
The standard coil diameter is 12mm. To ensure a high precision fit in the HCR, the copper is calibrated and hardened. The 0.7mm thickness guarantees that no metal
fatigue can occur in the bends. The large diameter allows small pressure drops or bigger circuit and eliminates the risk of blockages or noise from water circulation.
Barcol-Air uses highest quality copper, which has been tested for flaws (Eddy-current test), to ensure that absolutely no leakage will occur during the entire lifespan
of the products.
Heat Conduction Rail (HCR):
HCR's are high precision extruded aluminum profiles. Standard HCR's are:
S12 = HCR 2.5" [63.5mm] copper tubing 12 mm Small HCR 2-Pipe
SD12 = HCR 2.5" [63.5mm] double copper tubing 12 mm Small HCR 4-Pipe
L12 = HCR 3.5" [88.9mm] copper tubing 12 mm Large HCR 2 Pipe
LD12 = HCR 2.5" [63.5mm] double copper tubing 12 mm Large HCR 4 Pipe
S15 = HCR 2.5" [63.5mm] copper tubing 15 mm Small HCR 2-Pipe
SD15 = HCR 2.5" [63.5mm] double copper tubing 15 mm Small HCR 4-Pipe
L15 = HCR 3.5" [88.9mm] copper tubing 15 mm Large HCR 2 Pipe
LD15 = HCR 2.5" [63.5mm] double copper tubing 15 mm Large HCR 4 Pipe
G12 = HCR 4.5" [114.3mm] copper tubing 12 mm Gypsum HCR 2-Pipe
GD12 = HCR 4.5" [114.3mm] double copper tubing 12 mm Gypsum HCR 4-Pipe
The HCR's are cut to length, for an optimal fit on the ceiling panel. Standard lengths can range up to 13' [3.96m] other lengths on request.
Bonding:
Very High Bonding Tape ensures a highly efficient heat transfer between panel and HCR. The bonding tape is permanently elastic and allows different material expansion rates.
Simulated life cycle tests performed on the bonding show that even after 20 years of operation, no measurable reduction of the heat transfer rate or the adhesion can be
detected. The heat transfer is 100 % reproducible, which ensures that the cooling capacity is the same in the laboratory as on the job site!
The key to high performance radiant panels lays in the quality/precision of the individual components and the know-how in the production
process! Strict adherence to precisely defined / controlled production processes ensure long term operational reliability and 100% reproducible system performance during
the entire life cycle of the product!
Accessories:
- Barcol-Air brand header nipples complete the integrated approach to efficient installations. The use of one piece, precision-machined brass ensures that the system will be leak tight and installed with a minimum of difficulty. It is designed to receive the 10-12-15 mm push-fit coupling of the flexible hose on one end, and various solutions are available for the connection to the piping (NPT, soldered, ProPress, etc).
- Sauter EGH 102 dew-point monitors and transducers are recommended for dew-point controls. The system reliably prevents condensation in chilled beams - ceilings by
interupting the control signal to the cooling valve (closes valve) when the relative humidity exceeds a threshold value (95% rH).
1/2" NPT
O-Ring
Segment Ring
Visual guide to ensure correct push-fit depth
Project specific connection to water mains
1/2" ProPress
1/2" Solder Cup - The sensor is always mounted on the first panel in the CHWS loop (coldest spot!). One sensor per control zone is required.
