Industrial freezers, backup generators and hospitals
Quick questions regarding freezers, meat lockers, grocery stores and hospitals.
How long does a backup generator last if there's no one to turn it off?
How long would one last for a deli at the local supermarket? How long before the meat would spoil? Become putrid? What about other produce like fruit and veggies.
How long would a backup generator last for a hospital? How long before donated blood would thaw?
It depends on several factors.
One: what sort of generator it is - if it's a deisel generator then it depends on how much diesel is in it. But usually not more than a couple of days. If it's a gas fired generator, like the ones in hospitals etc, then it will continue to run as long as there is gas flowing through teh mains. So, unless the gas is turned off or runs out it can run more or less indefinately. If it's a coal/wood fired generator, such as you would get in some older hospitals etc then, depending on whether the fires were on a constant burn or they were lit for the purpose, then you could get a day, maybe two without refuelling.
Meat goes off at room temp in about 30 hours. Less if it's hotter.
Blood is not usually frozen unless there is a severe overstock. It's usually kept refriedgerated and will last for 42 days in a fridge. Platelets will last for 5 days. If blood is frozen then it will thaw in a couple of hours, depending on the conditions.
If they are taken out of a refridgeration unit then you're looking at a day or two. Maybe three. But you would need to check with a doctor about that.
Also, veggies etc vary, depending on the type of veg and the treatments it's had. Lettuce and greens will last a few days, onions and potatoes and apples etc will last a month or so.
Excellent answer, shaldna. I don't dispute an part of it.
I happen to shop at a the flagship store consistently rated as the US's best grocery store chain. (Luck of the draw, location-wise--but damn, other stores suck in comparison.) When the power goes out briefly, the shopping floor has minimal lighting. The refrigerator cases, beer cooler, and deli do not have back-up power from the generator. I'm not sure if the freezer cases do. However, the storage portion shoppers never see is all kept at the proper temperature, since a great deal more stock is there than on the shopping floor.
When the power is off for an extended period, which has happened twice while I've lived here, more of the shopping floor is served by the generators, so the shopping experience is very nearly normal. Obviously this depends on a decision (probably by corporate) to use additional generators and to get them up and running. It's usually at least 24 hours after the power goes before this happens--and this is at a great store which is making serious profits.
So in your fiction, are there people who have the authority and capability of getting more generators fueled and the power they produce to the parts of the store that were not considered important enough to instantly be powered by the main generator? If there's something catastrophic going on, employees will not put the store's needs first.
Ask to talk to the store manager where you shop. Tell him or her you're a writer and want to get a detail right, and see if s/he'll talk to you then and there, or make time for you at his or her convenience.
Maryn, shy but not scared of grocery store managers
Last edited by Maryn; 03-29-2010 at 05:24 PM.
Maryn made a really good point here about the fact that very little produce is actually on the shop floor. I used to work in ASDA and we kept the majority of perishables out the back in cargo container sized fridges and freezers. The chiller was just slightly above 1 degrees to keep the produce as cold as possible without freezing, but the freezer was a deep freeze at around -18degrees.
Because these are heatproofed air tight containers, well insulted, they will stay cold for several days, especially teh deep freeze, after power is turned off. I would say that you might get five or six days out of the deep freeze before things thawed out, maybe more dependsing on stock levels - more stock means longer thaw time. After that you'd get another couple of days assuming room temp gets reached.
Thank you all for your answers.
So, it's safe to say that after about 33 days it will all go to pot then, because there is no one around to refuel generators or anything.