Fridge fits in tight space, but will it be dangerous?

October 6, 2012 8:36 PM

Fridge filter: squeezing a fridge into a space which doesn't quite meet the suggested air clearance minimums - what might happen?

My mother wants a new fridge. The one she wants would fit in the existing cavity, but would have 10mm less clearance on each side than the manufacturer's minimum air clearance specifications, which specify a gap of 20mm on each side (ie 10mm more - twice the gap).

In all other respects the cavity is far bigger than the minimum specifications. The space behind the fridge is 200mm (min 30mm) and the top is effectively open (800 mm v min 50mm). Furthermore the leading 150mm of the fridge proper (+ the door) on one side would stick out from the cavity.

A smaller cavity presumably means less airflow. Is this potentially dangerous? Or will the fridge just have to work harder (be on more frequently) to overcome this? Is this likely to markedly reduce the lifespan of the fridge?

(Obviously smaller fridges are available, but she wants the capacity, and would prefer the aesthetics of a bigger fridge in the existing cavity. If it's just a question of energy efficiency she'll take the hit, but if she's risking burning down the house…)

posted by puffmoike to home & garden (11 answers total)

Probably not a big deal if the other openings are large. Fridges take heat from the interior and radiate it into the room. You might use a bit more electricity to keep a fridge cold when the heat won't radiate efficiently, but it won't burn down the house.
posted by weapons-grade pandemonium at 8:40 PM on October 6, 2012

here is my anecdote:

my tenant kept shoving the fridge back so it was no longer at the minimum clearance and it kept burning out some part of the fridge's workings. there were scorch marks on my wall from it. so. potentially dangerous--i don't really know--but, in my case, it ruined the machine and it had to be replaced (first an expensive part and then the whole fridge).
posted by crush-onastick at 8:46 PM on October 6, 2012

The problem is that the fridge expels heat through the sides/top/back of the cabinet. An air gap of 10mm isn't going to draft very well. Potentially this could cause the fridge to work longer, harder and less effectively which can result in the short term in poor cooling and in the long term damage to the fridge. In your particular case you are significantly limited the cooling capacity of better than 50% of the fridge. The lack of a cabinet immediately above the fridge though is a big plus.

There is essentially no risk of fire; the exterior may get uncomfortable to the touch but is very unlikely to reach a temperature that would ignite a standard gyproc wall surface.

The best of both worlds would be to look for a fridge that is the size she wants but features a fan forced condenser (IE a fan blowing over coils on the outside of the fridge). Downside: these fridges tend to be on the expensive end of the spectrum and everything else being equal will consume a smidgen more electricity.
posted by Mitheral at 9:04 PM on October 6, 2012

Can you prop the fridge up a little, maybe on 2x4s, so there's airflow underneath? That'll help the heat in the back create a draft-- it'll get dusty as hell back there, but it'll have nice airflow.
posted by Sunburnt at 9:14 PM on October 6, 2012 [2 favorites]

Sunburnt has the solution.

You NEED airflow to allow the heat taken out of the fridge (aka cooling) to be transferred away from the fridge - otherwise it doesn't work well, cool efficiently, and eventually will fail (sooner that it would otherwise).

Anecdata: at work, the execs' bar fridges were in cabinets. Even though they had cooling slots in the back of the cabinet, the fridges died young - eventually they wised up and took the cabinets away ...
posted by GeeEmm at 9:40 PM on October 6, 2012

Mitheral, every non-fan-forced fridge I've ever seen has a simple radiator grid on the rear only. Provided this one can be arranged in such a way as to provide decent convective airflow over that (perhaps by raising it a little as Sunburnt suggests), why would narrowing the side gaps be troublesome?
posted by flabdablet at 9:43 PM on October 6, 2012

They aren't all like that; many fridges have the condenser coils integral with the cabinet. If there aren't any heat dispersing coils in the cabinet sides then yes the side gaps would be redundant. Most fridges like that specify a zero side clearance though.
posted by Mitheral at 9:56 PM on October 6, 2012

A fridge is basically a heat pump strapped to a space heater; it takes the heat from inside, and puts it into the radiator on the back via the pumped radiator fluid. In order for that heat to go anywhere, you need cooler air flowing past and through the radiator; the radiator warms up the cooler air, mostly by conduction. The warmed up air moves away (mostly rising), thus moving the heat into the room in general by convection, and drawing in cooler air from below to replace it. There's also a bit of direct heat transfer by radiation, but that's fairly small compared to the conduction/convection cycle. The sides of the fridge are also used to conduct heat away, but the bulk of the heat transfer is done at the back - as long as you have some gap, you should be ok there.

So you need three things

1) a place for cool air to flow in - from the sides and/or bottom
2) sufficient space for the air to flow across the radiator at the back, transferring the heat
3) a space for the warmed air to rise and leave, at the top

By cutting down the amount of air flow coming in from the sides, it 'chokes off' the cycle; you'll end up with warm air 'trapped' at the back because it can't 'suck in' cold air to replace it. Or you might end up with cold and warm air mixing at the top, again cutting down the clean flow of air across the radiator, and a hotspot at the bottom of the radiator because air only flows around the top part.

More space at the back will help though, as that gives a greater volume of air to absorb heat, even if it is moving away more sluggishly than it should, and you won't have any problem with heat reflection from the wall.

The end result though is that you'll probably end up with a radiator that gets warmer than it should; which means the condenser won't be as effective at shedding heat, which means the fridge will be less efficient at moving heat from inside to outside; so it will likely have to pump the fluid faster and/or more often to keep within temperature range. You might burn out the compressor pump early, and spend more on electricity, but it seems very unlikely to cause a house fire -
a) the fridge will fail first, causing it to trip out and stop altogether rather than just pumping more and more heat into the back space (this is by design)
b) because of a they don't get hot enough to actually set anything alight
c) you don't keep anything easily combustible back there anyway

There are a few workarounds for this though, given you have a lot more space to play with at the top and back, and you will still get some airflow via the sides. The best bet would be to do as Sunburnt suggests, and prop the fridge up on a mini plinth with a gap (20cm or so) underneath; that will allow air to flow naturally under the fridge and provide the cool air at the bottom of the radiator to keep the air cycle moving. You can always cover up the gap with some sort of grill/mesh - as long as it doesn't drastically restrict air flow, it will still do the job but not be so visible. If you have wooden floorboards with a gap underneath, a cunning option is to put a floor vent under the fridge.

Another option that springs to mind is putting a vent in the wall behind the fridge, at the middle/bottom - depending upon what's on the other side of that wall, you might be easily able to draw in fresh air by convection that way.

What makes up the sides of the space the fridge is going in? Might you be able to get a carpenter to fit a lattice panel on one side to allow airflow in?

A last option is active cooling across the radiator; you can buy fridges that have a fan built in to blow air across the radiator (often used for fridges designed for cabinets, and they usually also need a gap underneath) which forces air movement, but is noiser and costs more electricity.

It really does depend upon the rest of the kitchen though as to how much effort it's worth putting into it - if it's a warm room with poor air flow (enclosed space) already, then going below minimum clearances will make it even worse. If it's a cool room with good air flow already, say between a utility room and the rest of the house, then the fridge will be running efficiently anyway, so reduced air inflow via the sides won't be such a problem, and you can probably get away with it. The things are designed to work in a whole range of different domestic environments, and they do factor in a certain amount of 'end user abuse' into the minimums; but if you're already pushing your luck with a poor airflow warm room already, then you're putting more pressure on the condenser system and it will be a lot less efficient, and may burn out sooner due to the extra work being put on the pump. You also may void the warranty, as generally you have to have minimum clearances in order to be covered.
posted by ArkhanJG at 2:52 AM on October 7, 2012 [4 favorites]

Sorry, gap underneath should be 10cm or so if on a plinth - missed the edit window for typo!
posted by ArkhanJG at 3:00 AM on October 7, 2012

If the fridge in question is the kind with an exposed radiator at the back, and raising it is ruled out on aesthetic grounds, you could make productive use of the large amount of extra room your cavity has at the back. If you were to put a sheet of plywood back there say 100mm off the back wall, with the bottom of the sheet 200mm off the floor and a 200mm gap at the top as well, you'd create a U-shaped airflow channel: the radiator would warm and pull up the air in front of the plywood sheet, to be replaced by cooler room air running down behind it. You'd want to add a deflector shelf above the fridge so that the rising plume of warmed air exits from the front, away from the intake at the top of the sheet, and you'd still lose efficiency because even with a deflector the whole thing is going to be feeding from air near the top of the room which will generally be warmer; but it should still work better than having a pretty-much-dead air space in the back of the cavity.
posted by flabdablet at 3:32 AM on October 7, 2012

Thanks to everyone for the responses. I could pretty much mark all as "great answers" - I'm just going to mark ArkhaGJ's as "best answer", for going above and beyond with explanations.

Given Mum's house is relatively cool, the the room is fairly large and there is lots of space behind and above seems like I can safely say the pros outweigh the cons, especially if I lift it off the floor a bit. Thanks mefites!
posted by puffmoike at 7:01 AM on October 8, 2012