19
$\begingroup$

I've always wondered why refrigerators don't have some of their parts located outdoors like an air conditioner.

In warm weather, it seems like it would make sense to have the condenser outside like an AC unit to avoid heating the room. In cold weather, it seems like it would be much more efficient to have the condenser outside to cool down faster. Why is the condenser still indoors?

First, does this exist in some places? Have I personally just never seen it? Maybe for large commercial, refrigerator/freezers?

If not, would the cost simply outweigh the benefit? Is it cheaper to have the AC cool the room down after the fridge has heated it slightly rather than install another condenser outside? In cold weather, is the fridge acting as an efficient space heater, so putting the condenser outside not really get you anywhere? I'd be interested to see if a cost/benefit analysis has been done.

Finally, is it just convenience? Is it simply much easier to just move the fridge in, plug it in, and be done?

Improve this question
$\endgroup$
7
  • $\begingroup$ If I think about a domestic frisge with the radiator grill outside, I come up with a very headache-y piping between fridge and wall. the coolant should have a high steam pressure, but then you could have problems with bubbles accumulating at high points. plus what if your kitchen is south facing? $\endgroup$
    – mart
    Feb 15, 2015 at 12:33
  • $\begingroup$ Also there's economic aspect of having most of the work and QA etc done in factory, so you can ship a finished unit and don't have work on site - who gives the warranty for that? $\endgroup$
    – mart
    Feb 15, 2015 at 12:34
  • 1
    $\begingroup$ The air conditioning sits outside all year. I guess my thought was that the piping would be a one-time (more accurately: very infrequently) installation with some standard fitting. Then the fridge and condenser would be purchased separately. Plug and play. Still much more complicated than the current scenario, but I would think the bulk of work would only be done once. $\endgroup$
    – Justin Trzeciak
    Feb 16, 2015 at 13:26
  • 2
    $\begingroup$ A fridge's job is to cool its compartment, and the radiator must be out of the compartment. Its convenient to have it all as a single (indoors) unit. An AC cools a room, and its necessary to have the radiator outside the room. $\endgroup$
    – Jesvin Jose
    Feb 27, 2015 at 10:36
  • 1
    $\begingroup$ In cold weather, it would be a waste of good heat to dump it outside. It's not just efficient, it's free heat. $\endgroup$
    – MSalters
    Apr 9, 2015 at 21:45

6 Answers 6

Reset to default
12
$\begingroup$

Electrical powered domestic refrigerators developed from ice boxes, also known as cold closets, which were tin or zinc lined insulated cabinets that had a ice compartment. As the ice melted it kept the inside of the ice box cold.

For premises not connected to the electric grid kerosene refrigerators were developed and are still available, kerosene refrigerator. There are even refrigerators powered by gas and propane.

Alternatively powered refrigeration units are still produced.

With mains/grid powered refrigerators, as you allude to, the compressor and power unit of electrically powered refrigerators are part of the domestic refrigeration unit for convenience. It is possible to have the compressor and power unit outside the premises as occurs with split system air conditioners but it would be inconvenient.

By having grid powered refrigerators as a compact unit they can be placed anywhere, inside or out, connected to a power outlet and they start operating.

For refrigeration on an industrial scale, cold rooms are used. Depending on their scale and portability, the compressor and power unit are on the outside.

Improve this answer
$\endgroup$
4
  • 1
    $\begingroup$ Also, something I think is important, is that the temperatures inside the house are quite constant (at least with less variations than what exists outside the house). This makes it easier to design a more efficient system. $\endgroup$
    – gromain
    Feb 16, 2015 at 9:15
  • 1
    $\begingroup$ So bottom line then is just the convenience? It would just be a ton more work for very little efficiency improvements? $\endgroup$
    – Justin Trzeciak
    Feb 16, 2015 at 13:27
  • 1
    $\begingroup$ For ordinary household refrigerators, yes. It's cheaper to buy because there's less materials. In that regard their more resource efficient. $\endgroup$
    – Fred
    Feb 16, 2015 at 13:33
  • $\begingroup$ It's really not too different than if you look at the installation costs of a central air conditioning system. The cost of the equipment for the contractor is (relatively) cheap--for a residential system on the order of maybe around $1000 if memory serves me correctly. It's the markup you get from having to buy through a middle man and the labor to install the refrigerant lines, ducting, etc. that ends up resulting in the high costs we associate with air conditioning installs. $\endgroup$
    – Secundus
    Jun 14, 2017 at 12:29
8
$\begingroup$

The cost of installing and maintaining a split refrigeration system for cabinet style refrigerators would swamp the cost of the refrigerator itself.

For large refrigerated rooms, or whole house cooling systems, the cost of the entire system is greater than the cost of the labor and maintenance.

Given mass manufacturing, though, it doesn't make sense to sell a $400 refrigerator that requires a lot more money to install, including holes, routing pipes, placement of an internal and external unit, etc. Further, it would decrease reliability and require more maintenance.

Lastly, there is actually little efficiency to be gained. It's such a small space to cool that the little heat increase in the summer isn't large, and is offset by reduced heating in the winter (when a refrigerator with an external unit would actually have to work harder).

It does make sense (and is more efficient) for much larger cooling requirements, but not for small refrigerator sized consumer appliances.

Improve this answer
$\endgroup$
1
$\begingroup$

In the winter, you're paying to run the refrigerator when you shouldn't need to run it at all. However, since we're also paying for heat and the refrigerator is generating heat then our furnace doesn't run as much and it doesn't make much difference.

In the summer, we're paying to cool our homes and the heat from the refrigerator makes that cost more. So this is really the biggest problem but it can be solved without moving the condenser outside. Both options have already been mentioned.

It's much easier to pipe air in and out then it is to pipe a pressurized coolant. If we insulate the back of the fridge and insulate the duct going outside we could exhaust the heat. Of course, you could simply use a fridge in a garage or on enclosed patio perhaps.

Sure the fridge would cost more to make but it's just a bit more plastic and insulation. If the manufacturer can claim it's 32% more efficient or even 25% that a huge selling point these days. And yes the duct work would cost more for sure but we need a duct anyways for the stove vent.

In the end, times changes, what was economic before might one day make total sense. And you could even do it yourself. It's just a matter of how good you want it to look. I'm sure many people could even recess it into a wall or cabinet so you wouldn't even see it. Others could match the paint, bevel the edge and make it look totally normal.

Just my opinion.

Improve this answer
$\endgroup$
0
$\begingroup$

I agree that it doesn't make sense for the refrigerator to heat up an air-conditioned space in the summer. Also, if the temperature is below freezing outside, why not just locate the fridge in an uninsulated and unheated part of the house ie garage or balcony? If the ambient temperature is already cold enough, the refrigerator's thermostat will not turn the unit on.

I solved the winter problem by using the fridge in my garage. The summer problem is more complicated. Commercial walk-in coolers and freezers do have their condensers outside, typically on the roof. The next time you stop by a Dunkin Donuts, wawa, or large restaurant in a strip mall, look up at the roof. You will see at least 3 condensers, or 2 condensers and a package unit (large unit that houses condenser for air conditioning, and furnace for heating), where the refrigerator, freezer, and air conditioner each have their own condensers.

Well, a commercial walk-in fridge or freezer is around 15,000 USD for low end, much more money than the 600 to 1200 USD for a home fridge. As the other comments and answers have pointed out, it doesn't make economic sense to separate the condenser outdoors for a home fridge. My approach was just use an insulated flexible duct to vent the exhaust hot air from the fridge condenser outside. If we put the fridge on a wall that faces outdoors on the other side, the duct would only need to be a foot or two.

However it is difficult to attach a duct to fit the exhaust area of the fridge that is typically at the bottom for the upright fridges. I mean you can do it as a hack with alot of duct tape but it would look funny and unprofessional. Perhaps, with a lot of requests for this type of adaptability, the manufacturers might consider incorporating a standard for duct outside venting of condenser exhaust.

Improve this answer
$\endgroup$
1
  • $\begingroup$ While it doesn't really make sense, as you said, to heat up an air-conditioned space with the refrigerator, it really comes down to economics (also like you said). I was wondering when I read your post, however, did you just put a duct over the top of your fridge coil? I don't really see there being enough convective air flow to cool without a fan, and you would probably spend more in a year to power a fan for a tiny duct than you would on the slightly higher cooling load. You would have to have a supply duct drawing from the exterior or you end up still pulling in the air conditioned air. $\endgroup$
    – Secundus
    Jun 13, 2017 at 23:47
0
$\begingroup$

It can make sense to install the condensor outside and this is done in large industrial systems (This is what condensors of large AC or fridges look like, look for those on the roof or behind any installation you'd expect to have significant cooling needs). However, it has drawbacks. Separating condensor from fridge means you need to install piping onsite, this includes:

  • vents in the high points and low points of the piping, for emptying and filling
  • Piping through walls
  • quality control or even pressure test
  • filling and checking the system after installation, refridgerants are at least potentially hazardous

A longer piping run would neccessitate a larger compressor - though m gut feeling is not by much (Pressure needed for condensation will likely dwarf losses of a few m piping.).

This would turn a mass produced consumer product into a piece of bespoke plant design.

My guess is that a trained technician + 1 assistant can do this for most applications in half a day, so you would a person-day skilled labor to the cost of the fridge. Or in other words: You're now introducing contractors that are (usually) in a hurry to get to the next job into the equation vs the factory tested package system.

Hattip to secundus who made the point I wanted to make clearer.

Improve this answer
$\endgroup$
0
0
$\begingroup$

Modern materials would make separation an easy thing to do. Homes could be built with ducting to accommodate such a system. Right now a length of tubing is already used for the water supply for an ice maker. The connections can be designed to fit together without venting problems requiring re/filling the system. Many refrigerators sit and accumulate dust for years gradually loosing efficiency and causing degradation of components. Separating the parts may allow for easier cleaning. Refrigerators generate heat and moisture which can attract insects. They are noisy and do add heat to a room. My guess is that the suggestion will become something people will want and pay extra for as electricity savings becomes more apparent when dependent upon alternative power sources for the home. I would also like to see designs that retain the refrigerated air instead of dumping it when a door is opened. There surely is a better way.

Improve this answer
$\endgroup$

Not the answer you're looking for? Browse other questions tagged or ask your own question.