Managing a refrigerator as an ice box , to save energy.

Managing a refrigerator as an ice box , to save energy.

The days are very hot in Cebu Philippines when it's not overcast. I bought the best refrigerator that made sense for us, but most things available here are low quality.

 If left plugged in all day, the refrigerator heats up the space and continually works against itself. There is no nice cool place to put it. I tried it for a couple days and it never stopped.

 The in-laws have never had a refrigerator before, and it shows. On many occasions I have had to explain the concept of thinking about what you want before opening the door and then accomplishing the task quickly. They say that it's plugged in, so it will stay cool. The oldest sister stands there dumbfounded until her feet get cold. Nova is tired of yelling at them.

We aren't storing anything long term in the freezer. We go shopping and use up most things before going again. Meat and fish are available on the roadside and are purchased as needed. So it only needs to be really cold when we are storing leftovers. The rest of the time it's a vegetable crisper.

 It works much better at night when the temperature goes down to about 78 Fahrenheit. It is usually plugged in from about 11:00 p.m. until 5:00 a.m.. This is enough time for the containers of water in the freezer, to all freeze solid. It gets unplugged in the morning and becomes an ice box. The family understands the concept of quickly dealing with the ice box and then getting the door closed. They have often used ice in the past.

Wet towels draped over the top and sides worked pretty well as an evaporative cooler, but I have been unable to get anyone else on side, and explaining the concept of evaporative cooling, has fallen on stubborn ears.
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I bought this fridge to serve an immediate need. Now that I know how inept everyone is, I won't be buying a refrigerator for relatives in the future. Nova and I will still have a small one. Once we are situated on a farm, where a larger amount of refrigeration is needed, I will mostly deal with chest freezers which work more efficiently. They will have styrofoam added to every surface.

Anyone else living on the property, including paying guests, will be given a block of ice when they need it, to be used in a Coleman type cooler. Because they are top loaded, they are naturally more efficient. They will be able to see their ice melting, which will encourage sensible use.

I anticipate placing the refrigerator and freezer adjacent to a clay brick evaporative cooler that utilizes more than 2,000 pounds of brick. On days when the temperature reaches 85, it is likely to be around 70 degrees by the evaporative cooler. Things that come into the house quite warm , such as fruit and vegetables, will be placed inside the evaporative cooler. Some may be then placed in the fridge or freezer and some will remain in the cooler until they are needed.

For now, I use a makeshift evaporative cooler with a fan. Air blown over a wet floor and damp clothing draped on chairs, is much cooler when it reaches the refrigerator. This stream of cool air is directed at the hot portion of the fridge, when it is plugged in.

How about stick a bright light in it, maybe motion detection so it turns brightly on when someone opens the door?

Or wire it to a siren that comes on after 5 minutes.

My old fridge had a buzzer on it that started after about a minute of the door being open. it was just  in-case you didn't quite shut the door, but it would give someone a definite time to have the door shut by.
Or put a child lock on it, the type that screams when it's opened. I'm sure they might disable it when you're not there but when you are around somewhere it should work.  If the fridge is heating the room it is in it's in too small a room though. We had that issue at a hotel I worked in, two chest freezers and upright and a walk in fridge in the same small store room soon pushed the room up over 30C and that was in England where it was 15C outside!

I've lived in Ladakh through the advent of fridges in the life of people I know here. In the 1990s nobody I knew here had a fridge, and restaurants only used them for "cold drinks." When one of my local friends first got a fridge in the 2000s, they mostly kept "cold drinks" in it. I told them about leftovers and yogurt and stuff like that, and at first they were skeptical, but within a year or two they were using the fridge as it should be used. It will come, though slowly. Now I even have one myself!

Electricity here is unreliable and goes off for a few hours now and again, so I don't use it for long storage of vulnerable things. The store had a choice of different models so I got one with higher energy star rating on it. I keep plastic bottles full of water in the freezer compartment whenever there is space for them, and keep the freezer on the colder setting. And I keep glass bottles of drinking water in the fridge when there is space. These function as thermal mass to keep everything cold when the power goes off, and they seem to work well. I find that with the power off for several hours, it still stays cold, eg the ice cubes don't stick together. Even though I don't drink things from plastic bottles, guests and friends do, so I have bottles to use. For the freezer, water will swell and the bottles could break when they freeze, so I squeeze the bottles a bit before putting them in, and don't put them in totally full. For the fridge that's not an issue so I keep glass bottles for cold drinking water as well as thermal mass.

A plastic bottle of frozen water in the coolers might be easier to handle than a chunk of ice.

All of our freezer thermal mass is in discarded plastic soda bottles. We seldom need more than 10% of the freezer compartment. Most of it is filled with these containers. The door of the fridge and other places contain glass coke bottles. So I'm handling thermal mass in just about exactly the same way as Rebecca. This thermal mass is what allows the temperature to carry through until evening. There is always some ice in the upper chamber at the end of the day.

When others are using  chest coolers, I expect to give everyone their chunk of ice in the form of a frozen bottle.
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The room with the fridge is quite large. The entire space gets hot, during hot days, but not nearly as hot as it was before my arrival. I have turned the whole place into a swamp cooler.

This fridge has its coils built into the sides and they heat up the outer sheet metal. When designing refrigeration for a farm, I will put the coils from a chest freezer in a pool of water, so that evaporative cooling can always keep the coil at an efficient temperature. Hot water would be a byproduct of running refrigeration. This could be done so none of the heat is retained in the room containing the refrigeration unit. By keeping them separate, the fridge or freezer would actually have a cooling effect on the room.

If you can place your pool high up and stick a shower head on it then you get hot shower. or maybe make the pool a bathtub. Then you also get a hot bath:)

I have a chest freezer that I converted into a refrigerator.  The problem with upright freezers is that you open the door, the cold runs down onto the floor.  With a chest freezer, the cold can't run out the bottom so it stays much colder when you open the top.  Freezers are also much more well insulated than refrigerators.  You can buy a temperature probe that goes in the freezer and connects to a thermostat that controls power to the unit.  You can set the freezer to 34 degrees or so and it runs as needed.  Another possible option.

I will keep mine as a freezer , since I'm unlikely to find a useful used model. If an old free one were obtained, that might be an option for a secondary unit. Stuff is kept here, long after it is obsolete.

I intend to set the temperature gauge as low as it will go. That way , when the unit is filled with food and water bottles, it can carry through for several days of power interruption. We will always have at least two ways of making electricity , in order to avoid spoilage.

The largest thing I expect to slaughter is a pig. Seldom more than 200 pounds. So the primary job of the freezer will be to provide the ice for portable coolers and day today ice for refrigerators.

The coolest place to keep an ice box, is inside an evaporative cooler. A very large one is needed for air-conditioning purposes. It will be used like a giant zeer pot, to chill things before they enter the ice box or freezer. On an 85 degree day, it's possible to bring things to 70 degrees through evaporation. I'll be happy to have an icebox at 40 degrees, so the differential inside the evaporative cooler is only 30 degrees fahrenheit.

Dale Hodgins wrote:

The coolest place to keep an ice box, is inside an evaporative cooler. A very large one is needed for air-conditioning purposes. It will be used like a giant zeer pot, to chill things before they enter the ice box or freezer. On an 85 degree day, it's possible to bring things to 70 degrees through evaporation. I'll be happy to have an icebox at 40 degrees, so the differential inside the evaporative cooler is only 30 degrees fahrenheit.

A precooler/outer cooler is an awesome idea. I am puzzling my way through a design for a precooler on the outside of the kitchen wall, accessed through a window or hatch; with shade, venting, and some sort of evaporative cooling, but most important outside the thermal envelope yet inside the insect/animal-proofing.

I often finish cooking a multi-day meal at 10-12 at night.. at this time of day it is plenty cool outside most of the time, even in summer, but warm inside. And I want to go to sleep. So the whole damn thing goes into the fridge and the fridge works hard to cool it, dumping all that heat into my house...

Dumb enough in summer, but the solar can handle it. A big problem in winter when the solar needs every edge..

Quick question, Dale: are you salting your bottles of freezing water?

This only works if that bottled water becomes a dedicated heat transfer fluid, but the freezing temperature of a saturated brine is something just under -23 C. That might give your iceboxes a little more longevity between ice bottle refills.

-CK

I don't currently salt the water, but I understand there can be a benefit. I think it's more likely that the bottles will always be filled with drinkable water, so they can be consumed as they melt. I don't know that lowering the freezing point is necessarily advantageous. Most things that go into a cooler, don't need to be frozen solid and those coolers won't ever be far from the freezer, so it's pretty simple to recharge. The change of state from liquid to solid requires about the same amount of energy as an 80° change in temperature. The ice can be further chilled if necessary. I can see an advantage to keeping some salt water in the freezer, because during a power outage, the change of state happens at a lower temperature. This prevents a change of state within stored food... I copied this... The freezing point of the water is lowered. A 10% salt solution freezes at 20
 degrees Fahrenheit (-6 Celsius), and a 20-percent solution freezes at 2 degrees Fahrenheit (-16 Celsius).

Regarding the evaporative pre cooler, this will be something about the size of your average bathroom and located inside the house adjacent to the refrigerator and freezer. Stacked bricks with just enough space between them to allow airflow. Incoming air will pass by and through the evaporative cooler as it passes through the house. So it needs to be at one end, rather than central, as would be done with a heating unit. It's very cheap to produce extra square footage here, so I may give up as much as100 square feet to a large multipurpose evaporative cooler, that includes a walk-in section for vegetables and openings containing ice boxes... I've come up with an idea for an evaporative cooler bed with a waterbed mattress that always stays cold. The cool air envelops the sleeper. But unlike air conditioning, there is constant flow of new air from outside, rather than constantly cycling of the same air. Just as with an air conditioner, the lowest temperatures are found within and adjacent to the unit. The mattress will be embedded into the top of half a ton of cool masonry  materials.  This will be a separate topic.

The testing that I've done so far, indicates that I can get up to 20 degrees fahrenheit drop in temperature when blowing air over dampened materials. The evaporative cooler will work best in the morning and early afternoon. Usually the relative humidity gets too high by 3 or 4:00 p.m., for an evaporative cooler to do much. I've found that when I put several gallons of water on the tile floor, it evaporates quite rapidly, making those tiles quite cold, up until 2:00 p.m. most days.

During periods of prolonged rain, the cooler won't work, but that's when temperatures are generally between 73 and 76 fahrenheit. On most days when temperatures become uncomfortably hot, the relative humidity becomes low enough for a few hours, allowing evaporation to really do a good job. Swamp coolers don't generally work very well in the deep south of the U.S. This has to do with very high relative humidity when air conditioning is most needed. Most attempts I've seen have been concerned with blowing cool air for immediate relief. I've had good luck with cooling heavy masonry materials, mostly when relative humidity is below 80%. Here at 8 degrees from the equator, the hottest days we've experienced in over three months, is 91 degrees, and during those days, there were long periods with humidity suitable for evaporative cooling. I've experienced much more stifling heat in southern Ontario.

> A precooler/outer cooler ...

Dillon, in San Francisco, many older multi-unit buildings still have exactly what you describe built into each unit. There is a back door foyer between the kitchen and the back stairs and off one side of this foyer a large bin extending out of the building which is built into the wall about waist high, often just below a window. There is a crude door that provides access which is let into the wall of the foyer (which usually consists only of a single layer of 3/4" planks) and the bin is usually built of wood planks with 1" screen on all sides and a wood top to keep rain off. The bottom is crude and not waterproof, allowing any water to drain out. The ones I've seen have been in good condition if they haven't been demo'd for remodeling or such.

Cheers,
Rufus

I agree with running the fridge at night and off during the day. Also the split type refrigeration is a good strategy. However the other tricks mentioned I'm afraid are not correct. For example storing less food will only give you more trip to the market with no electric savings. Also maintaining the lowest temperature in the fridge will only give you more bills.

You do realise there are refrigerator climate classes?

Ones for 'normal', 'sub tropics', and 'tropics'. It's an international system, so should be marked on the tag attached to the fridge.

The one you have sounds dodgy, maybe best relegated to being an upright freezer or, alternatively, a beer (drinks) chiller.

Also, fridges don't work well if they're continually turned off/on; and, are best kept full to maximise thermal effectiveness.

Pop-riveting a latch and using a padlock to the door will deter people leaving it open. It's common practice with the typical garage beer fridge here - for security!

julian Gerona wrote:I agree with running the fridge at night and off during the day. Also the split type refrigeration is a good strategy. However the other tricks mentioned I'm afraid are not correct. For example storing less food will only give you more trip to the market with no electric savings. Also maintaining the lowest temperature in the fridge will only give you more bills.

We generally buy enough to fill the fridge and then we use it up before going back. The fridge is not maintained empty. The freezer always contains a bunch of water bottles. If we are just storing fruit and vegetables , i unplug until we go to the market and buy meat.

The fridge is set to the maximum but it never reaches it since there is a lot of water to cool. Set it low so that it will run continuously when the air is cool.

Dale Hodgins wrote:

julian Gerona wrote:I agree with running the fridge at night and off during the day. Also the split type refrigeration is a good strategy. However the other tricks mentioned I'm afraid are not correct. For example storing less food will only give you more trip to the market with no electric savings. Also maintaining the lowest temperature in the fridge will only give you more bills.

We generally buy enough to fill the fridge and then we use it up before going back. The fridge is not maintained empty. The freezer always contains a bunch of water bottles. If we are just storing fruit and vegetables , i unplug until we go to the market and buy meat.

The fridge is set to the maximum but it never reaches it since there is a lot of water to cool. Set it low so that it will run continuously when the air is cool.

I think I misunderstood you. Yes that's the way to go, you want to fill the fridge so there is little space for air. The air is the culprit since every time you open it goes out. Minimal space inside means there is little air to cool down every time you open.

I woke up to a nice cool 78 degrees fahrenheit. Thought it might be a nice time to do some evaporative cooling, but then checked the humidity, 89%. So much for that idea. There was a hard rain last night.

One corner of the kitchen is lower. We have placed the table over that spot, and a shallow pond is maintained. The fan is placed behind us, so that air is blown over the wet floor and it swirls around under the table, becoming cooler than the surrounding air. A good portion of it discharges against the hot side of the refrigerator. This is bound to help efficiency since the air is cooler, it's moving, and heavier with the added water. I think a vaporizing fan would be best of all , so the little droplets would be constantly hitting the side of the fridge.

The floor pond has the added benefit of trapping hundreds of mosquitoes. The area is flushed daily , sending them down the floor drain. It's a shame that we aren't raising fish.