Standard VAV: Type NS, NB zero maintenance terminal units

Rectangular or circular VAV/CAV terminal with integral sound attenuator for low noise performance. 24 point flo’cross velocity sensor fitted for + 5% volume flow accuracy at 1 diameter from bends. Units can have multiple (4 outlets) or rectangular outlet configuration. General design criteria for 12° C primary air and t of up to 11° C to supply air diffusers at 50% primary turndown ratio with standard diffusers.

VAV Induction: Type NV, zero maintenance terminal units

Rectangular low height VAV terminal with integral sound attenuator. This unit can be used with normal or low temperature primary air temps(8° C upwards). The unit operates as a standard VAV unit but is capable of inducing void air to mix with primary air to give supply air temperatures of 12° C or more.

The induction effect allows a primary turndown ratio to 25% thus giving even more energy savings to the system all year round. Standard diffusers can be used due to the induction effect ‘creating’ higher secondary air volumes thus eliminating diffuser dumping. With no fan and no filters, this system is by far the best VAV system with the least maintenance.

Fan assisted VAV ; Type NX

Rectangular fan assisted VAV terminal complete with reheat coils and sound attenuator sections.

These units are used in conjunction with low temperature air 7° C upwards. They provide constant air volume to the space with VAV primary inlet turndown ratios to 15%.

These units have 24 hour fans and filters so maintenance/running costs are higher than the other VAV systems. Also the units are physically larger. Generally used in very high load areas but not for normal office density application.