A refrigerator problem

What happens to room temperature if I leave an open refrigerator for long?
a). goes down
b). stays constant
c). rises

It remains constant.

I would believe it would stay constant, but then wouldn't that overheat the motor and might heat up the area around the fridge for a little while? This is a pretty valid question.

Do you want the answer now or should I wait a bit longer for other responses?

Maybe give it a couple of days to see if anyone else responds.

I think I know the answer but I'm not sure about the physics behind it. Looking forward to being educated if you have this info.

Machines are not 100% efficient.
This means machines must consume more energy then the energy they can output.
The refrigerator motor would heat up more than the produced cold so the temperature in the room would rise.
If we had 100% efficiency we could have easily created a perpetual motion machine. 
With efficiency > 100% we would have opened a door to totally new possibilities for mankind, including intergalactical travel.

For example: 
solar panels - the hit of recent years - are only about 15-20% efficient.
a car's efficiency is only about 25%
and so on!

How does't thee calculate efficiency, mine comrade?  There was so much school didn't teach us!

After getting home from the fishing trip to the Isle of Skye that I mentioned in the response to the spider/snakes post, I recall that I put my catch of a few brown trout, and one of my buddie's catch in the freezer section of a fridge-freezer I had in an outdoor shed. I didn't shut the door properly. When I went into the shed next, nearly a week later, the door was still partially open but with the opening completely iced up. I didn't know what condition the fish were in regarding cooking and eating, so I threw both lots away.

Unsurprisingly, I didn't notice any difference in the air temperature in the shed. I can imagine however that it must have taken quite a lot of energy to make all that Ice and the motor would have been working overtime.

It's probably the same in Poland and the US in that the UK Patent Office refuses to accept any patent application for a perpetual motion machine. If it wasn't for that pesky Isaac Newton inventing Thermodynamics we might have had one  by now!    

@jadejohnsonindustries:

"The term efficiency can be defined as the ability to achieve an end goal with little to no waste, effort, or energy. Being efficient means you can achieve your results by putting the resources you have in the best way possible. Put simply, something is efficient if nothing is wasted and all processes are optimized. This includes the use of money, human capital, production equipment, and energy sources."

You can check out more at a variety of web sites. The above definition is from Investopedia.

Good luck 'cause the deeper I dig the quicker the subject goes over my head  

@johnr:

You are very right, John. Theory and reality often don't match. My version of the solution relies on certain assumptions:
- the room is completely airtight (hermetically sealed), so no outside conditions influence the interior of the room or in any way does the inside and outside environment infiltrate each other 
- there is ample time for the motor to run to increase the temperature of the surrounding air, the length of time dependent on room size and the power of the motor. Higher room air temperature doesn't negate the fact that ice can form in the closest vicinity of source output.

Too bad about the fish - probably tasty and could have been eaten 

As far as patents in Poland are concerned it's so bad that - at the end of the day - people prefer to apply overseas rather than in Poland...