Can I equip my lab with consumer refrigerators?

January 24, 2008 10:57 AM

Buying refrigerators for the lab: is there a good reason not to go with consumer models?

I'm in the process of equipping my lab, and I need some fridges/freezers (4 ºC and -20 ºC) for general-purpose storage. I do not need explosion-proof units. Doing some shopping (VWR, Fisher) for a compact unit, it looks like the professional laboratory fridges (again, not explosion-proof) cost about 5-7 times as much as consumer models of comparable size and temperature range. Is there any good reason not to just buy something from Best Buy?

I don't need precise temperature control, I just need it to stay below the set point. And how much of an issue could durability be? I've seen home refrigerators last easily in excess of 20 years. And at this price differential, I could replace the thing 5 times before I'm in the red.

posted by mr_roboto to science & nature (17 comments total)

The defrost cycle in consumer models can destroy some enzymes, but I am guessing you already knew that.
posted by 517 at 11:03 AM on January 24

No, I didn't. What's the precise issue? Am I safe if I go with a model without defrost?

I'm not storing any enzymes, but I have some chemicals that I'd prefer to keep below -20 at all times.
posted by mr_roboto at 11:06 AM on January 24

The labs I've worked in (Neurology & Pathology) used consumer refrigerators. Some expensive items were kept in commercial ones.
posted by senseigmg at 11:10 AM on January 24

The only danger that I've seen with using consumer fridges like this in a lab setting is that people are then tempted to put food in them.

Just put a bunch of signs saying "No food storage, EVER" and you should be okay.
posted by gregvr at 11:14 AM on January 24 [1 favorite]

Our lab has a couple of consumer type fridges, but only the small, under-the-counter types. We do have two large lab-grade fridges, one from VWR and one from Thermo Electric (Fisher).

We store solutions in the little fridges and the big fridges are for specimens, antibodies and cell culture supplies - things you can't replace cheaply if the machine dies over the weekend or something. And yes, the defrost cycle is not good for antibodies. Our big freezers specifically do NOT have a defrost cycle, and we have to manually defrost it every couple of years or so, once the frost builds up too much.

If you just need to keep stuff cold without having to worry about temperature fluctuations, the consumer models should be fine.

Also, check with your purchasing department on those prices - your university (I assume you at at a university!) probably has a discount agreement with Fisher that brings your costs down by maybe 30% or so from list price.
posted by mbd1mbd1 at 11:15 AM on January 24

And like most conversations about consumer vs professional, look at repairs.
A professional model may not break as much, but if it does, specialized people can repair it faster and there are probably more parts for professional grade things because the cost more and are likely to be repaired instead of replaced.
Like most consumer items, when a fridge breaks down, people aren't interested in why, they just pitch it and get a new one. Repairing a consumer fridge may not be worth it because there are many more models, thus fewer repair parts, and the price of a new one may be cheaper than the repair.
posted by ijoyner at 11:35 AM on January 24

the reason lab refrigerators are different than home model is ventillation/wiring, lab refrigerators have all the wiring outside away from the inner compartment and well sealed, the last thing you want is volitile/possibly caustic chemical fumes accumulating in a closed space and the possibility of an electrical spark (caused possibly by fumes corroding the insulation around the wire) which could lead to a very large bang. I am a chemist and we recently replaced our frig, the inside metal was fairly corroded despite the fact that the frig was about 7 years old and the chemicals were all in closed containers. Caps and bottles leak (or small drips on the sides aren't cleaned properly) leading to fumes no matter what so I would always spring for the frig that was designed with that in mind as opposed to keeping your lettuce crisp.
posted by estronaut at 11:55 AM on January 24

My mom does purchasing for NIH and I've seen consumer models around her lab (amongst the super-critical cold vaults and such) used to store non-critical things like media or sugar solutions (with condiments and hot pockets, too). So, it's certainly common practice.

The only reason for buying the Fischer Sci. one where there's no environment-critical contents might be for auditing and compliance purposes. For instance, if you were storing isotopes or medical equipment, safety and security regulations might stipulate that a freezer have so and so certification. You might want to run it by your compliance officer.
posted by cowbellemoo at 12:01 PM on January 24

I'm assuming you don't need flammables storage as well as the higher explosion-proof grade.

If you're not storing anything labile (reactive, acid, caustic), there's no particular reason for not choosing consumer grade items. Just don't pick frost-free models with a hot defrost cycle. We've used chest freezers for decades for low-temperature environmental sample storage.

For god's sake use a fridge monitor though. At least get a simple hi-lo monitor, they're only $50 or so. I just outfitted our lab with iTCX network monitors from Omega. They're quite the treat. They'll mail alerts and can even send SMS or to pagers. I've had several cases where a cranky cold-room mechanical/power failure has been mitigated because monitoring units. Highly recommended if you care about the contents of the fridge at all. These also satisfy ISO 17025 requirements if you keep them calibrated.
posted by bonehead at 12:32 PM on January 24 [1 favorite]

I think for the fridge you should be fine with a consumer model, but I don't know how easy it is to find a non-frost-free consumer -20. If you want your stuff below -20 at all times, you want a non-frost-free freezer that does not defrost itself (as many previous commenters have said).
posted by pombe at 12:48 PM on January 24

Besides the defrost cycle, temperature control in general might be an issue. A 20 degree swing might be OK for a hot pocket, but not your application.

I'd also be surprised if a consumer grade freezer goes down to -20 at all.
posted by gjc at 1:07 PM on January 24

Whoops, I misread. -20C is -4F. Probably within the capabilities of a consumer model, but longevity might be an issue, as it would probably run constantly.
posted by gjc at 1:09 PM on January 24

As a data point: we've had a single consumer-grade chest freezer operating continuously at -20C for more than a decade. It's mostly used for film storage.
posted by bonehead at 1:30 PM on January 24

In all the labs I've been in (mostly biology), all the fridges are consumer models (without the auto-defrost cycle; we want the temperature to stay constant - constantly cold) except for -80'C freezers and 4'C fridges with sliding glass doors.

If you're keeping chemicals in them, will they be volatile? Otherwise, consumer models should be fine.

Also, some "laboratory" freezers have reporting services (extra wires connected to a thermometer inside the freezer; if it goes above a certain temperature it'll send out a "help! I'm to warm!") but you also need the monitoring services to go along with it.
posted by porpoise at 1:33 PM on January 24

all the chem labs i've worked in had consumer-grade fridges. however, ditto estronaut on the ventilation. the last one was about 15 years old and packed full of ancient stuff, and every time you had to open the thing, you'd get hit in the face with a billowing cloud of horrible noxious shit. (especially thiols. gah!)

so, yeah - do your students a favor and at least get one with ventilation if you're storing lots of organic stinkies. otherwise, if you have just a few non-volatile things, a regular old fridge should do.
posted by sergeant sandwich at 2:52 PM on January 24

No volatiles, no flammables. Good call on the monitor, bonehead. These guys look perfect: programmable logging and high/low alarms at $75 a pop.
posted by mr_roboto at 3:33 PM on January 24

Whoops, I misread. -20C is -4F. Probably within the capabilities of a consumer model, but longevity might be an issue, as it would probably run constantly.

0 ºF is the standard recommended max temp for consumer grade freezers; I don't think it's a big deal.
posted by mr_roboto at 4:27 PM on January 24