https://drive.google.com/file/d/1bd5Y1UjT6-sgpz1M_pVYwyXafneIiOzg/view?usp=sharing

Crawl space is a great spot to get radon gas!

RoyC: Thanks for setting us straight. You’re the best thermodynamicist I know! Of course the heat flows equal out over a long enough time scale so my first calculation was correct. The heat moved out through the condensing coil equals the heat that moved into the fridge over time, as you stated.

We seem to be having some misunderstanding about refrigerator thermodynamics. It is true that the heat rejected by the condenser is greater than the electrical input. However, there is also heat being conducted from the room to the inside of the refrigerator and this helps cool the house. Conservation of energy tells us that over a long period of time, the energy entering the refrigerator (electrical and heat conduction from the space) equals the energy leaving the refrigerator (from the condenser). Thus, the net heat load on the room is just the electrical consumption. This ignores some other additional loads like putting hot food in the refrigerator and removing ice from it, but those are usually relatively small.
In terms of putting the condenser outside, this would help decrease electrical consumption in the winter, but increase electrical consumption in the summer. The net impact on overall home energy consumption would depend on the space heating/cooling system characteristics. The refrigerator with an external condenser would also be a much more expensive piece of equipment due to the additional complexity needed to operate over a much wider range of external conditions.

And about venting that damn refrigerator, is it ever worth it after considering the temperature and humidity of the makeup air?

When well educated, respected members of the community admit on social media that, for example, having a supply register in the garage is nothing to worry about, absolutely nothing, well, then I just give up. Explaining BS then becomes like the story of Sisyphus in the Greek mythology: endless.

Allison, wouldn’t that 600 kWh/yr represent just the energy to run the compressor, fan and lights and not the energy being moved from the food (and water, if there is an ice maker) to the conditioned space? While it isn’t going to make it a huge load, with a COP of 4, the fridge would be adding more like 1000 BTU/hr to the load of the house.

You are forgetting that a refrigerator is a heat pump and has a COP of more than 1. It is pulling heat out of the refrigerator and dumping it into the room. the heat from the house is working it’s way into the fridge but the fridge is working harder to pull it out faster than it comes in. And in climates like ours here in Crematoria (TX) fridges work harder and run longer in the summer because most houses are not kept at 72*. Any heat you can get out of the house is a benefit.

That said what is far worse is the better halfs computer rig. Her office is hot year round as the PC and monitors etc are like running space heaters in there. I have yet to design an outdoor cooling box to put her tower in or find a way to put it down in the crawlspace. When I move her office to a larger room it will probably get a minisplit. And lets not talk about is the door open as no it isn’t and no it can’t be.

Ross: Definitely not worth it if you’re using the same system serving the house. We’ve done plenty of HVAC designs with conditioned garages but always with a ductless unit.