8 Magnet Room Venting Requirements
8.1 Venting System Requirements
The Magnet Room requires the following venting systems:
1. HVAC
2. Emergency Exhaust
3. Pressure Equalization
4. Cryogenic venting
8.2 HVAC Vent Requirements
1. HVAC vendor must comply with Magnet room temperature and humidity specifications and
RF shielding specifications
2. RF Shield vendor must install open pipe or honeycomb HVAC waveguides
3. All serviceable parts in the Magnet room (e.g., diffusers) must be non-ferrous
4. Waveguides must be non-ferrous and electrically isolated
5. Incoming air must contain at least 5% air from outside the Magnet room (inside or outside
the facility) to displace residual helium
8.3 Emergency Exhaust Vent Requirements
1. Exhaust vent system is supplied by the customer
2. All items within the RF enclosure must be non-ferrous
3. The exhaust vent system must be tested and operational before the magnet is installed
4. The exhaust intake vent must be located near the magnet cryogenic vent at the highest
point on the finished or drop ceiling
5. Any space between finished ceiling and the RF ceiling must contain an additional exhaust
intake vent (to prevent helium from pooling above the finished ceiling)
6. If there is no space between the RF ceiling and finished ceiling, the intake vent may be
located on a side wall (must be on the coldhead side of the magnet, near the coldhead, with
the top edge of the vent flush to the finished ceiling)
NOTE:
If used, vent diffusers must not extend beyond the vent opening to prevent helium
from pooling between the edge of the diffuser and the ceiling.
7. The Magnet room exhaust fan and exhaust intake vent must have a capacity of at least
1200 CFM (34 m
3
/minute) with a minimum 12 room air exchanges per hour
8. The exhaust fan must be installed outside of the RF shield and must remain fully functional
in the magnetic field per the fan specification sheet
9. The exhaust fan must have appropriate waveguides and di-electric break to maintain the RF
shield requirements (see
RF Shielded Room Requirements
)
SIGNA Voyager Pre-Installation
Direction 5680008–1EN, Revision 2
Chapter 3 Magnet Room
83