Hospital Essential Electrical System Rule of Thumb
Hospital Essential Electrical System Rule of Thumb
(OP)
I've been told a quick rule of thumb for emergency generator capacity for hospitals is about 6va/square foot. (Obviously, good load calculations and historic measurements are the only way to know for sure.) This is only for doing a preliminary guess at a generator size, accurate load calcs will be done later on. Does anyone have any examples that can reinforce or debunk this theory? How about a recent project where you know the actual generator capacity and the actual square footage of the building for comparison? This would be a full-blown hospital with all the trimmings - surgery, emergency departments and so on.






RE: Hospital Essential Electrical System Rule of Thumb
Regards
RE: Hospital Essential Electrical System Rule of Thumb
You need to be very careful in the early stages of planning that you include all the loads which will ultimately be fed by the EPSS. In California we have specific loads which are required to be fed by the two branches of the Emergency Power Supply System, (Life Safety and Critical Branches), as well as the Equipment Branch. In some cases such as that we have recently finished the Facility Planning and Physical Plant management there are additional systems which a facility may want on the system which are not specifically required to be connected by code and which must be on a fourth priority branch.
We learned too late that some imaging systems now require higher levels of emergency power than in the past, (we had to add additional distribution capacity). Some factors we use are:
Surgery Center/Acute Care Hospital-6 va/sf
Medical Offices-1.5 va/sf
Radiation Therapy- 4 va/sf
Central Plant- 10 va/sf
IT Building- 55 va/sf
Administration- 1 va/sf
Parking Structurs- 0.5va/sf
We have validated all of these in the past and the figures provide a good guide to preliminary planning.
Good luck with your project.
RE: Hospital Essential Electrical System Rule of Thumb
What about those imagining loads? What's the va/sf for an MRI imaging suite? Same as radiation type loads?
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Hospital Essential Electrical System Rule of Thumb
RE: Hospital Essential Electrical System Rule of Thumb
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Hospital Essential Electrical System Rule of Thumb
How about a separate transfer switch to the equipment branch? Hospital administration should be involved in a decision like this. Hope they understand what you are talking about.
RE: Hospital Essential Electrical System Rule of Thumb
Keith Cress
Flamin Systems, Inc.- http://www.flaminsystems.com
RE: Hospital Essential Electrical System Rule of Thumb