If we assess an Industrial Process Area which has workstation heaters we’re instructed to consider creating a zone at the workstation which is conditioned but not separated from the surrounding unconditioned zone(s). The size and shape of that workstation zone (how high should it be for different types of heater) is however down to the assessor and with virtual boundaries, I’m not sure how SBEM allows for the ‘indirect heating’ that’s going on.
One of the considerations I find myself making is the range over which the workstation heating may be having an effect. If the heater type is your more common electric fan heater stuck under a desk or fixed to a nearby wall, then the effect is very local (and will drift straight up to the roof). A convection heater is likely to be even less effective as the heat will go start its journey to the roof as soon as it exits the heater…..!
An infra-red radiant heater on the other hand can have an effect at an appreciable range from the heater and with thoughtful positioning in relation to working area and activity, can make life more comfortable for staff. But how do we (as mere energy assessors) make that determination and what guidance if any do Conventions give us as to the size and processing of these workstation zones?
Also note that iSBEM expects an infra-red electric radiant heater to be entered as an ‘Unflued Radiant Heater’ heating type (see the SBEM Manual) and I assume as ‘Unflued Radiant Heater’ for the Heat Source (although the ‘Direct or storage electric heater’ option also appeals to my common sense). This gets me wondering if SBEM is treating such heating in the same way it might treat roof mounted radiant beam heaters which I see as a very different animal…….