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Power ratings -- choose level VI Take a look at any external power supply (EPS) you have lying around -- you should notice, along with all the regulatory markings, a roman numeral I through VI in a circle. Here are four that I just dug up in my house: These indicate energy efficiency standards for EPS starting with the California Energy Commission in 2004 (...


5

I use a pair of wool fingerless gloves. They don't impair dexterity and even though they leave fingers exposed they cover enough that my entire hands remain comfortable.


3

Clarification of terms: Your tap is the downstream end. The City water supply is the upstream end. My understanding of your situation: City Waterline Building shutoff vale Local distribution valve Cold wall Tap you trickle. I don't know that your building valve and local distribution valve are or are not the same. You want to know if it's safe to use ...


3

Human is quite an energy-efficient, kinda. if I remember correctly - pro bicycle riding on a closed track exercise about 0.5kwatt for about an hour - those are pro guys (there was some video on youtube about that) and not pro guys they will have a hard time being even close to that. if one is just in a good shape it is not enough. the electric car spends ...


3

This is simply a fancily designed chain of cities based on the about 40 years old idea of the "compact city". The idea is to reduce urban sprawl, reduce traffic and improve living conditions. Each link of the chain in itself will be not self-sufficient, but provide all necessary (daily) needs to its inhabitants, including doctors and if not a ...


3

Having shut off many fridges and freezers for storage, I can tell you exactly what happens and why. It will quickly become contaminated with mold The interior of a freezer has some plastic "skin" to present a surface that is more aesthetic and easier-to-clean than galvanized steel. However, the freezer does not stop at the skin; behind the skin is ...


3

One way to increase the efficiency of an upright refrigerator or freezer is to fill up all of the "unused" airspace with something that won't flow out of the unit every time your open the door (as air will) nor facilitate convection heat transfer from the bottom to the top of the compartment even when the door is closed. If you have some plastic ...


2

So if you only need a small capacity and high energy efficiency, one model that is popular in the sailing community is https://engelcoolers.com/ They have a reputation for efficiency. Can be used with 12/24v DC or 110/220 AC There are cheaper brands, but whether that is the most economical in the long term is another issue.


2

Leave the faucet open at a trickle. From Consumer Reports: Let the cold water drip from a faucet served by exposed pipes. Running water through the pipe—even at a trickle—helps prevent pipes from freezing. Doing this at the two sinks is probably sufficient (no need to leave the shower or toilet running). You can use something like this to divert the ...


2

I'll assume for now the earlier answer on indoor heating systems that you linked remains correct, and address two other points. Heat pump efficiency and temperature Engineering toolbox provides a thorough explanation of heat pump performance, which includes this chart: A few definitions: COP stands for coefficient of performance, and is a measure of heat ...


2

10 CFR 430.32 - Energy and water conservation standards and their effective dates is the U.S. government standard defining (among other things) how energy consumption of refrigerators is to be tested. The standard references the test procedure AHAM HRF-1-2008, developed by the Association of Home Appliance Manufacturers, an association which "is an ANSI ...


2

According to the manual, the Kill-A-Watt is calibrated to accuracy within 2%, with 0.5% being typical. In contrast, any conventional electrical load which you might have in your house won't be calibrated at all. It will have some maximum current limit, but beyond that, even for the same product, the actual load might vary by as much as 10% -- there's simply ...


2

A properly made normal thermometer will function perfectly well in a refrigerator, as you describe. As with all mercury based thermometers be careful not to break it. Cleaning up and then dealing with the released mercury would be problematic. If that were to happen contact the waste disposal department of your local municipal council and get advise because ...


2

Although it seems logical that a refrigerator would be more efficient since it doesn't have to keep things as cold, there are a few different factors affecting real-world performance. Freezers are simpler to operate. In a freezer there's only a top end on the temperature range. From refrigerator manufacturer LG you can see the range in the refrigerator is ...


2

A "city" implies people. Lots of people. Those people need to eat. Food generally is purchased at (super)markets and grocery stores. It usually is delivered by trucks. No roads means no trucks means no markets means no food means no people means no city. I see a teeny, tiny problem with the plan, don't you? Of course, one can transport and ...


2

Some years ago I read of an off-grid farmstead in Australia that used a conventional chest freezer as a refrigerator. The way he did it was to use a probe and temperature controlled relay to turn the freezer on and off. He added 2" of closed cell XPS polyurethane sheet to the front, ends and top, but not the back, as the radiant grid was under the skin ...


2

I've used them. I've never been happy with them. If you do use them you need to follow these rules: If you wrap them you must have the wraps evenly spaced. You can't have 3 turns per foot at one end of the pipe and 6 turns per foot at the other end. The temperature sensor (disk on the orange blob) must be pressed tightly against the pipe. The full ...


1

If we compare the cost of solar/wind renewables vs fossil fuels, both Without subsidies, what is cheaper? You have to understand the different roles of different power sources. Coal is old-fashioned and dying. Traditional coal power plants have poor thermal efficiency, and alternatives such as integrated gasification combined cycle are expensive. Coal has ...


1

@jmk yes the Seasonal energy efficiency ratio or SEER a high number is better. The system won’t let me comment must be because I am new on this page of the SE . There are similar questions asked on DIY home improvement. Basically the outside unit is the compressor and condenser coil. The inside unit could be a very basic coil and orifice and your system ...


1

Since I ate a lot of food, I asked to myself if maybe a train (dividing cost between all passenger) was more green than me! A train typically uses electricity. The emissions of electricity on the greenest grids are typically around 50 g / kWh produced. In the near future I think we can even reach zero with hydrogen energy storage and renewables. However, a ...


1

It appears that some of these thermostats have "compressor delay protection," such as this one: https://www.amazon.com/dp/B01HXM5UAC/?th=1


1

Why not simply install trace htg to the problematic pipe? Of course that's assuming you can access it! Insulation, of itself, does not stop freezing but simply slows down the heat loss.


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I think the greatest efficiency improvement can be obtained by cleaning the condenser coils on the bottom and/back . In a home unit the coils,especially on the bottom collect a lot of lint , pet hair , etc. Vacuum them annually or more often. I have also added aluminum window screen to protect the coils from lint. If you use foam ,I think you will find ...


1

Put your hands under the laptop, laptops dispose of waste heat with their fan systems It's very warm. Another trick, microwave a mug of water til it boils then seal plastic wrap so it cant spill.......instant hand warmer


1

One problem with using such "blanket" as you describe is that it can also insulate the keyboard. If you are using a desktop computer that may be okay, but it you are using a laptop computer you risk overheating the computer through insulating it and also possibly restricting or blocking the exhaust vent for the computer. Like Jean-Paul Calderone ...


1

Since the water heater is not on an exterior wall, it is likely that the pipes you mention which do pass through the exterior wall would freeze before pipes inside the heater do. This would cause damage, of course, but might spare the heater. Addressing the issue with pipes freezing, there's an interesting discussion over on HomeImprovement.SE: "What is ...


1

My understanding is that AC-to-DC converters each have their own "sweet spot" in which they achieve their rated or advertised maximum efficiency. Any device has a "sweet spot". This does not mean the design is terribly inefficient far outside of this sweet spot. In general, you can see that a typical AC-to-DC converter is passively ...


1

At any given thermostat setting, for any given amount of time, it will be more efficient for your gas water heater to be turned off than to be turned on. As described by Newton's law of cooling, the rate of heat loss of a body is proportional to the difference in temperatures between the body and its surroundings. Comparing the two situations - heater on ...


1

tl;dr: heat pumps are widely used for swimming pools, can probably be used for hot tubs, and should work reasonably well in your climate. Swimming pool with cover I couldn't find good information on hot tubs, but I did find that the U.S. Department of Energy has this page on heat pump water heaters for swimming pools. Then, a quick search suggests that ...


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