It's been a while since I've done an OR - so I can't help with loads - but what I remember is that the airflows are much higher than the equipment loads and that there was reheat anyway.
The only suggestion would be to catalog all equipment in the OR - talk to manufacturers and get heat gains.
They are putting more and more electronics in operating rooms. Call the manufacturer of the equipment. Normally it isn't too signifigant.
Usually the determining factor is the number of air changes required by the AIA guidelines for medical facilities. 20 to 25 air changes per hour will get you in the ballpark. Different jurisdictions may have different requirements.
Don't forget the surgeons want about 62 degree F space temperature. This is to prevent them from sweating and dripping into the body cavity. They are all gowned up you know. Hacking on peoples bones and cartilage can be hard work.
This means that your typical 12 ton air handler is now about a 6 ton unit. You have less delta T from supply to return.
I know that the airflow will account for the equipment load, but I am working on a study and the owner has requested me to line item loads, so I wanted to know if anyone had a good Btuh/sq ft number for the equipment load in an operating room. I do not have a good number because of what all of you are saying, the required ACH is more than enough to account for the equipment, people, and lighting loads.
Just to firm up the lower space temperature in the OR, it has nothing to do with sweating. The reason they want the lower temperatures (in orthopedic OR's) is to slow the drying time of solvents used in the procedures.
If anyone has an approximate equipment load for an OR I'd appreciate the feedback. A calculation or some kind of documentation would be much appreciate also!
HVAC is not my field, just a bit of an interest, I am an electronics engineer that once worked in a hospital.
You are going to have normal building loads, plus occupancy (obviously) that may be up to a dozen people in a very long complex operation, such as brain or heart surgery. There can be several surgical teams that work in rotation, sometimes two teams may be present.
Then there will be the total electrical input, which includes high intensity lighting, patient monitoring equipment, life support equipment, that could easily add up to several Kw I would expect.
The number of air changes will need to be fairly high, manly because electro surgery creates rather foul smelling smoke from burning flesh, plus the use of flammable medical and anesthetic gasses and volatile liquids.
The whole operating room problem is rather different, including a much higher than usual level of air filtration. Obviously dust and pollen can be sources of infection, airflow direction is always downward to settle dust.
I cannot give figures, only point out some of the basic requirements to someone not at all familiar with hospital operating room procedure. You probably really need some very expert advice.
