Motors running compressors and heater coils are the biggest household electricity expense. I am appalled by the “experts” claiming money saving tips who have no clue how a freezer works. Finish this article and you will be an expert kitchen thermodynamicist.
I once read a magic book called “The Trick Brain” which ruined magic for me forever. It described how to produce a magic trick by random selection of objects and effects. I can no longer enjoy an illusion without having some clue of it’s method. I will now reveal the secrets behind the cause of kitchen cost.
First, a response to this stupid Money-Saving Freezer Tips which encourages the masses to perforate themselves, friends and family by filling and freezing boxes full of fiberglass insulation. If you have ever worked with angelhair fiberglass you know you itch for weeks and sharp broken bits of glass fiber in your lungs will kill you as you bleed with every breath – not something you want near your food or digestive tract.
Fact: It costs more to keep a lot of ice frozen than a little. Keeping an extra mass at a lower temperature is less efficient under any circumstance, regardless of how much of it is fiberglass or insulating air it traps. Any energy spent cooling freezer blocks is wasted when you remove them to use that space for food. Freezer blocking can also cause problems by restricting the cooling fan vents which prevents smooth refrigerated airflow – causing the fan to work harder and longer.
Better to retain as much refrigerated air as possible. Here are a few small efficiencies to get you started. Keep in mind heat rises. Keep long-term and warmest at the top. Keep space open at the bottom before you head to the market – They will cool quicker at the bottom, then rearrange them early in the morning when the kitchen is coolest. Plan your load to keep popular picks by the handle and seldom selections by the back corner of the hinge. For example: 98% of the door openings are not to retrieve a frozen chicken – that’s long term coldest so near but not on the bottom and in the back corner behind the hinge. Perhaps a popular pick is popsicles – prepare the package by tearing off the top and placing it handles out on it’s side near the top in the door rack or by the door opening, where refrigerator manufacturers design the placement of ice-makers and ice trays. Then train the kids and kids-at-heart to only open the door enough to quick-pick, not swing it wide open and then decide or dig. Plan your grab to not let the heat in, so know WHAT you want and WHERE it is before you open the door.
By the way, C Lazarus, you picture a piggy-bank on your freezer shelf, that’s just too ludicrous for a response. Try this – dump the Sherbet Tubes into the ice tray instead of reaching over the box lid, and rearrange the corndogs so the handles are easy to grab when you crack the door open a moment. Then read Money Saving Freezer Tips – Thermodynamics in Your Kitchen and learn not to exchange warm air for cold while quick-picking. There once was an ad-campaign for bottled ketchup accompanied by Anticipation – Carly Simon (#13 – 1972) which highlighted the viscosity of their product. What it fails to mention is that when you pour ketchup your are actually pouring two fluids, air is the fluid which replaces the ketchup – the ketchup can’t get out of the glass bottle if the air can’t get in to replace it – the ketchup is held in the bottle by the vacuum of it’s own weight. When you put something in your freezer you push cold air out and the displacement is matched going the other way as well. So try to be an Olympic diver and leave no splash – not a ham-handed cannonball on entry and an oriental fan on the way out.
Thermal Theory in Hot Water
This was written in response to an assertation of a wive’s tale by Meerkat1. The statement of opinion was tagged at the bottom of a normal post:
“Meerkat1” <firstname.lastname@example.org> wrote in message news:student-B73D25.email@example.com…
> Helpful Kitchen Hint: Need a copious amount of ice cubes for that
> special party? If so, fill your ice cube trays with boiling water (in
> place of tap water). They will freeze faster. This hint brought to you
> by your Iron Chef.
> Meerkat1 – Chief Engineer
> RADP Pavilion
Sorry, Myth Busted! …brought to you by wiz, your favorite feroequinologist.
There is no special property possessed by piping hot water, that isn’t also possessed by luke warm tap water, to make it freeze faster. Very few substances are liquid when cold and then solid when heated, and none I can think of go the other way – warm solid to cool liquid. An egg, when cooked, breaks down the long chain protein molecules into many short coils, visualized as a box of wet spaghetti changing into a box of interlocked coil springs, that’s what causes a cake to bind.
There is, however, thermodynamic proof that starting with the coldest possible liquid reduces the time to achieve a solid. That truth applies equally to molten iron, liquid helium, DHMO (Dihydrogen Monoxide), Hydroxilic Acid, pure H2O and common tap water which likely contains chlorine and fluoride as well as a host of suspensions, solutions and particulates such as rust, lead, valve grease, calcium, even dead (and some live) bacteria, below government approved maximums of course, if you’re lucky.
If you had claimed “Piping hot water loses heat more rapidly than room temperature water.” then I would not have been compelled to dispute it and write this article, for that statement is indisputable. Room temperature water is already room temperature and the rate of Calories per hour exchanged nets zero. Hot water exhibits a steep but diminishing rate of C/hr decline.
TAKE THE HEAT OFF
(relax the pressure)
Now it is possible that the purest of water, containing no dissolved suspensions or particulates, can remain a liquid when super-cooled, because without a “seed” it has the ability to refrain from forming a crystalline structure. (which explains the ‘cool’ magic trick of tapping the surface of water with ones finger to make the ‘freeze’ it in a fraction of a second.) The freezing temperature of water solution can be lowered with other dissolved mixtures, such as salt and alcohol. That’s why I keep a jar half full of cheap vodka in the freezer for kitchen burns, it remains in a liquid state and is quicker and more envelopingly effective than a cube of ice at lowering skin temperature. That’s also why road crews sprinkle salt on iced roads – subtract several degrees from the dangerous slick road conditions, by lowering the freezing temperature of the ice, the saltwater flows away harmlessly (unless you are life downstream.) Mix ice, salt and alcohol around your ice cream maker tub to get it colder than ice. (you can’t taste frozen ice cream, only when it’s melted has it flavor.)
Pressure has an effect on freezing as well as evaporation – the lower the pressure the quicker the ice and the steam – lengthen your cooking time at a greater altitude, because the water will boil at lower temperature. Pressure cookers shorten cooking times by increasing boiling temperature. Some steam locomotives superheat steam (making ‘dry steam’) by routing it out of the steam dome through the fire tubes of the boiler to conserve water and utilize less steam more efficiently as the pressure increases with temperature, allowing greater expansion in less time to drive the piston cylinders, instead of using powerfully wasteful ‘full compression’. So to make ice cubes the quickest, start with chilled water from the fridge and freeze it in a vacuum.
(a one way road, from hot to cold.)
Always remember that you can’t create cold. Heat only flows from warmer to cooler. Your refrigeration contraption, including air conditioners both automotive and buildings, can only add more heat to the surroundings. Running a 1500 Watt refrigerator adds the equivalent heat of running a 1500 Watt hair dryer the same length of time. Heat exchangers, which keep two fluids separate yet transfer heat between them, can be found in heating/air-conditioning ducts, nuclear power plants, and cooling gasoline engines or warming car heater air in the form of a radiator, as fluids need not be liquid – atmosphere behaves fluidly. Your heat pump contraption (refrigerator/freezer) collects heat from the cold side with a lower temperature heat exchanger tubing (usually filled with refrigerant in a gaseous state) coiled within the freezer compartment that then circulates out to the hot side where it is compressed to a liquid by an electric pump, increasing it’s temperature to higher than the kitchen ‘room temperature’ and into another heat exchanger on the ‘hot side’ where the hot liquid radiates the heat away to the room. Just like inside the ice-chest portion of the refrigerator, heat still only flows from warmer to cooler, but now from the hot radiator coiled on its back, into to the room where the hot/liquid side of the cycle is exposed to atmosphere, rather than from the air inside the ice-chest to the heat exchanger of the cold/gaseous portion of the cycle. In order to separate the two sides, the pump sucks on the cold side, creating a vacuum into which the warm (now cooler) liquid passes through a tiny hole, that aperture is known as the Bernoulli Valve named for the guy that figured out that in order for the liquid to expand into a gas it takes a large amount of heat. Guess where it collects that heat from. That’s right, the freezer. 110% of the heat energy removed from inside your refrigerator now heats your kitchen – the extra 10% or so comes from the electrical energy running the compressor pump, the friction of the coolant, the interior lamp bulb, icemaker motor and valve (if equipped) and the heater coils of the frost-free feature.
NO CAKE, JUST ICING AND FROSTING
(but you wouldn’t want to eat it anyway.)
An electric fan blows air across the heat exchanger built of tubes with fins hidden behind and/or beneath the walls of the freezer compartment. That chilled air then flows down across your frozen food and a portion of it is routed past a flap attached with a rod to the dial that adjusts the relative difference from the freezer to the fridge compartment. Limit opening the doors when humidity peaks, such as after you shower or put a kettle on for tea. Be aware that any moisture allowed inside tends to ice up this duct and can eventually prevent the fridge compartment from receiving any cold air at all. Due to this frost collection, refrigeration tends to suck the moisture out of items placed inside. The action of frosting lowers the humidity because the coldness of the tubes causes airborne moisture to collect on it, and quickly becomes frost. By removing the moisture, the air trapped inside of your refrigerator becomes dry – an action which costs Watts of electricity for the pump to run longer.
ADD MORE HEAT
Have you a frost-free fridge? You have HEATER COILS INSIDE YOUR FRIDGE! Now why would anyone want electric strips of metal that heat up and glow just like a toaster within a piece of equipment designed to keep things cold? Most refrigerators include a timer designed to reset itself periodically to a 24 hour cycle to shut down the compressor and turn on the heaters that melt the frost from the ducts and compartment walls when the doors remain closed mostly – basically while the household is asleep. If you frequently interrupt the timer, your midnight snacks are costing you more than your waistline, they are also increasing your energy consumption. Reducing the time the heaters are on to melt the frost, thereby lowering your electric bill can also be achieved by wiping off moisture before placing items inside, keeping fluid containers tightly capped, and pouring only as much as you are going to finish drinking instead of leaving an uncovered half glass of juice or milk to evaporate in the chilled air of lowered humidity caused by frost crystal formation. Heaters wrap the freezer compartment to melt the frost, the cool condensate (a bacteria farm that smells like all the nasty decay collected from things you’ve preserved in your fridge) pools beneath the freezer compartment and drains out through a tube to an evaporator – which is usually a simple pan near the floor. Recent improvements in energy efficiency involve an additional dehumidifier in the airflow from the fridge to the freezer compartments. The dehumidifier/condenser centralizes the moisture condensate collection, minimizing the surface area and time required to defrost it.
A/C in DC
Air Conditioners (A/C) also use the same method of cooling the cabin air – two heat exchangers and a refrigerant circulating from hot to cold. The first ever air conditioner used ammonia refrigerant to compress and vaporize for the heat exchange ciruit, which worked fine but was less efficient than modern refrigerants, all of which are environmentally toxic. It was installed in a chocolate factory so work could continue during the summer and was so popular the idea spread rapidly. Just like refrigerators, A/C produces a net increase in heat due to friction and even more so in a motor vehicle. In a car, for example, just the difference of having A/C versus not having it installed, before even turning it on, wastes energy with the friction of the additional pulley constantly spinning at the hub and friction of gripping and bending the drive belt. Burning petrol or Diesel heats the world just to get the drive belt moving. A modest amount of DC electricity is needed to engage the magnetic clutch on that A/C pulley to clamp it to the A/C compressor pump. Now the engine devotes additional horsepower to drive the alternator a bit harder, and the compressor a great deal harder. There is a little friction generated just moving refrigerant through the pipes and the most fluid friction in the system is at the Bernoulli valve.
Here in Los Angeles there is an air temperature range that doesn’t exist long. That range is from mildly warm to hot. When folks climb onto their portable couch enclosed in a solar oven on wheels, also known as a Black Sport Utility Vehicle, they crank on the A/C and drive away. As they pump the heat out they become more comfortable, and shed that heat onto everyone else. Multiply that by all the LA vehicles, homes, offices, stores and when uncomfortable warmth triggers a cascade of heat pumps, the ambient air is suddenly 10°C warmer for everyone everywhere. It is possible to add less energy to the system – exchange the hot air from the car by leaving doors open a few minutes first and/or driving a few blocks with the windows open before closing them, or better yet, park in the shade, the couch inside your portable solar oven on wheels stays ready to enjoy. Don’t crank up the A/C to blow hot air on your face at first. Instead vent outside air to lower interior temperature before engaging the air conditioner fan on low and directed to the floor so it can cool the air most efficiently and collect as a pool of cold air at the floor with the windows up. Now you are crussing, close the outside air to recirculate that pooled cold air and crank the fan up to blow your face off as much as you want to pitch your sweat out onto pedestrians as they complain about the heat you selfishly dumped on them.
Even when you are using A/C in a residential or commercial structure, you are pumping the heat out locally as well adding heat far away. The plant generating the electricity is most likely spinning generators with steam turbines, and the steam is probably generated by burning fuel, such as natural gas if you are lucky, but more commonly coal and bunker oil. Imagine that, using heat to make cold.
It is also possible to warm a room by pumping heat from outside in. If you were studying penguins, you could run the heat pump system to suck heat out of the cold air outside, just like the interior of your freezer, and pump it to the room you wanted to warm up, just like the kitchen. It may sound backwards, but surprisingly, it works.
When I was working all night at the land, the first thing I’d do when I got home was to crash in bed. The wife would get up and go to work. When I woke up, the house was comfortable until she got home. She’d leave open the front door, drafting in all the outside heat “for the breeze”, then stand in front of the fridge, both doors open, with her head in the freezer and cool air flowing to her feet. That minute of self pleasure cost enormous energy and made me sweat for the rest of the evening as the fridge tried to recover, pumping its heat out into the kitchen for several hours. “I’m just deciding what to make for dinner…” was her excuse. I almost put a padlock and hasp on the fridge doors, but instead I moved the computer under the window with the A/C unit and installed an internet security camera in the door of the fridge. “See honey, you can view the contents of our refrigerator from anywhere in the world!” And I asked her to plan ahead, know where what you want is, pop the door just enough cracked open to snag all the things you need then close the door gently to avoid puffing out the cold air, keeping it closed as long as possible. She still stood every afternoon in front of the wide open fridge “My what marvelous work you did installing that night-vision camera!” So much for my thermodynamic lessons in efficiency.
It takes a great deal of warmth to melt ice. The amount of energy to get a quantity of water ice from zero degrees Celsius to one degree is equivalent the energy to get the same quantity up the entire range from one degree and boil it at 100° Centigrade.
The same is true in reverse, It takes a tremendous amount of energy just to get the liquid water from 1°C to 0°C.
Personally, I’d like to keep my carbon footprint tiny, and not wasting resources keeps me greener to the world. I’ll make sure anything that goes into my fridge is at its coolest and driest, including the air exchanged by opening the door. Unless you have a pavilion nuclear power plant, filling ice-cube trays with boiling water and then placing them into the freezer uncovered is moronic on three levels.
1. Boiling water up you are about to freeze is a waste of energy. Save energy by letting anything hot you place in the fridge/freezer cool down to room temperature first.
2. Making your freezer work three times harder because you just skyrocketed the humidity up is a waste of energy.
3. Freezing water down you just boiled is a waste of energy and time. Save energy by letting anything hot you place in the fridge/freezer cool down to room temperature first and let the room do the freezers work for free. Trim freezing time by filling the trays in the morning when the cold water pipes are their coldest, or fill the trays from water chilled in the fridge for the quickest ice at home.
If your party needs several pounds of ice quickly, ask one of your guests to stop by the gas station/convenience-store/supermarket and pick up a bag of ice or two on the way in. When they bring it through the entrance, PRESTO! there you have instant ice. Petrol isn’t wasted, because trips are combined, and your kitchen stays cooler because you pay someone else to shed the heat elsewhere.
— better to learn by mistakes of others, — Wiz.
— erroneous examples as provided, — Wiz.
— than to learn by mistakes made for oneself. — Wiz.
— A bakers dozen out of 12 Wizards agree: “And far less painful. — Wiz.”