27

I only worked in the commercial/industrial field of steam and hot water boilers so take what I say lightly. Here is what the heating engineers told us; if you can set back the thermostat or reduce the buildings temperature for 8 hours or more then there is a cost savings and if you can't it is probably not worth anything. One of the main problems with ...


25

Since you say your backup heat is electric, I'd say that's what is using all the power. It could be that the weather is unseasonably cold and that the backup emergency heat is kicking in often. Your Nest Thermostat could be switching to AUX heat more often than your old thermostat would have. Since you say your nest thermostat is new (last summer), It is ...


25

Clamp Power Meter Buy or borrow a clamp power-meter with a "kWh" feature, that is, the ability to perform an energy measurement. Not all clamp meters have this, e.g. a "True RMS" meter performs an accurate power measurement for non-sinusoidal signals but still not an energy measurement. Open the AC unit or the electrical panel (careful, ...


23

It might be slightly more economical, but it also might be slightly worse for your health. Hot water dissolves plumbing (pipes, valves, fixtures, etc.) much faster, and what it dissolves is in the water. Lead is specifically of concern, particularly with homes prior to 1986 and with infants. There's a NY Times article that sums it up nicely with sources.


23

Do you have average temperature data for your area, so you can verify that it hasn't been "that cold". You didn't purchase any new electronics such as bitcoin miners with the latest craze did you? Have any close neighbors? Cheapest thing if you have no electrical test equipment: go to the meter, on a lot of them you can see the least significant digit ...


17

An Old Debate There are is a very old debate about whether it's better to leave the thermostat at a constant temperature or to turn the temperature down when unoccupied and up when occupied. I am in the heat-as-needed camp that believes in turning the heat up and down. One Argument From a theoretical perspective, I think about it this way: Your furnace ...


15

Economically, the difference is irrelevant. Let's say you need to boil one liter of water. The specific heat of water is about 4.2 joule per gram degree Celsius. Meaning, for every gram of water that we want to make hotter by one °C, we must supply one joule of energy. A liter is 1000 grams, and let's say the cold water starts at 15°C, and we want to go to ...


15

Mid-December through January were brutal in the midwest. Most days and nearly every night were below 10F. Normal heat pumps cannot work at such low temperatures. The heat pump was failing over to "emergency heat" This is just a big bank of electrical resistors. I have seen installations where these resistors were on dual 70A breakers and ran well over ...


15

See other answer for how to test for actual efficiency gain, but you're basically cooling your output coil with a swamp cooler. In commercial settings it's called a free cooler. Water is either misted or dripped over a porous substance that the cooling air passes through. It cools the air as it evaporates, but greatly increases humidity. The concern I ...


12

It helps for sure. There have been a ton of studies done on this and I have read at least 10-11. At one point in time I was going into a partnership for a "greening" business. Your variance is somewhere between 1-15%. There are a ton of variables. Here is an OK study I read a few weeks ago from FSEC. I personally don't like this study because they ...


12

Here is the science-based thermodynamic law that drives all this. Suppose you have 2 spaces, A and B, at different temperatures. Between them, there is some level of thermal insulation. No matter what is true about the insulation, this rule always follows: Thermal transfer is proportional to the difference in temperature. Take any random insulator (green) ...


12

Disclaimer: This question is about Air Conditioners. The "You" discussed below is an air conditioner owner. This answer is not about heat pumps, which are a different class of equipment (operating on the same scientific principle, but there the similarity ends). Well, an aircon owner would likely ruin their condenser coils* by letting water ...


11

Ceiling Fans Ceiling fans are most often installed to help keep cool in the summer but they can also help circulate the hot air in the winter. Some have adjustable blades to make them more effective for this use.


10

Okay, so I think I figured out the reason, and I learned a lot about HVAC in the process. The answer is that a ceiling fan is moving air at basically zero "static pressure." Static pressure in an HVAC context means the amount of resistance that the air has to moving. In a free environment, that's zero, or close to it, but in a tightly restricted system of ...


9

Economically, yes it costs less to start with hot water. However, you should use cold water anytime you need potable water. Hot water tanks are generally pretty filthy. If you were to drain your tank, you would probably be disgusted to see what comes out. Cleaning your hot water tank is something that every home owner should do, but very few do. Also, ...


9

A dehumidifier is about the same as a window AC unit with both parts in the house, for most purposes. They draw just as much power as an A/C unit of similar size (or more if they happen to be old and inefficient.) Given that the required energy labeling on A/C units tends to promote a degree of of paying attention to that, and it's much less clear on ...


9

The first problem here is the "100W" claim, which you here treat as the reference standard from which to compare. Actually, it's the most dubious claim of the bunch, and has never been reliable. I suspect it's a common mistake for people to fixate on the "100W" number since it's a unit they're familiar with, and that's why manufacturers toss it on the box. ...


9

If you gather and archive a local source of weather data, and operate the mist system on alternate days for a while, you should be able to gather a pretty good sense of the effect on power use, despite variations in internal and external temperatures & dewpoints. Over time, your data set will have "directly comparable days" as well as "...


8

Say your electrical bill is $100 a month. Now say you have a refrigerator, a computer, a window fan and your light bulbs in your house as your only electrical devices. Everything but your light bulbs are on 24/7. Fridge: 725W **NOTE MOST FRIDGES DON'T ACTUALLY RUN 24/7 THIS IS JUST FOR EXAMPLE PURPOSES* Computer : 125W Fan: 150W Lights (on 8 hours a day,...


8

A 0.0025 inch thick sheet of any solid has negligible R-value in-and-of-itself (for purposes of home insulation). The (relatively) calm air next to it does have some R-value, on the order of R 0.7. Heat flow is calculated using conductivity (U-value). U-value is the inverse of R-value. R-value has units of (square foot)(hour)(Fahrenheit degree)/(British ...


8

Disclaimer: I am located in central europe, so this may or may not apply for you. In our region, typically every energy company and several environmental NGOs offer a service to borrow an energy meter for free or with a very small fee. Like this one: https://www.swm.de/privatkunden/kundenservice/energieberatung/strommesskoffer.html (it's in german, but ...


8

Setting back your thermostat to any reasonable temperature for any reason amount of time will only save 5-10% over the course of a season. Apples to apples You can't simply compare your bill to your neighbor's bill. There are very numerous reasons why this is impractical. Different construction, exposure, consumption, equipment and more. Even two houses ...


7

Before I remodeled my house to have vents and radiant barriers and lots of insulation, I did put a water misting system on my roof using PVC pipes and drip mist emitters. The mist emitter was helpful because it broke up the water into a fine mist and sent it into the air, giving me evaporative cooling before the water even touched the roof. Also I had some ...


7

I think unplugging the refrigerators will both save electricity and reduce wear on the compressors, although I agree with others that if possible you should measure the usage, in part to decide whether any (possibly small) savings is worth the effort. Energy Savings Empty refrigerators are less efficient, since the compressor needs to cycle on and off more ...


7

Most forced-air HVAC systems in Residential are both heating and cooling. What might be efficient in the summer will not be efficient in the winter. So, where do you live and which do you use more? If you live in Arizona you optimize for cooling but if you live in Minnesota you optimize for heating. Then you just deal with a less efficient system in the ...


7

This is actually a very good thing for the future of the grid. It's just off to an awkward start (and a very late one). This particular awkward start could do this during peak power-demand times, mainly the hottest afternoons when everybody is running their A/C: Reduce the duty-cycle on A/C and electric heat to about 50%, which only matters if its duty ...


7

Your assumption is incorrect. More heat is lost when the difference between inside and outside temperatures is greater. So, if you keep the house at 72F (22C) it will lose heat faster than if you kept it at 62F (17C). Thus, your heater will need to run more often and/or for longer to maintain your desired temperature. It therefore uses more energy to ...


7

In a LOT of cases I've seen like this, it's turns out a problem with your water heater, assuming that if you have electric heat, you likely have an electric water heater. If the element is damaged, it leaks current into the water and immediately to ground, but because it's a high resistance ground fault, the breaker never trips. The fault in the element ...


7

It all depends how do you set up your not-smart thermostat VS how do you plan to set up your smart thermostat. They don't just save energy for the same use. If you set up non-smart thermostat for 'comfort always' you will pay more. If you will set up it as 'discomfort always' you will pay less. For the same level of comfort you need different temperature at ...


6

Everyone is saying, one way or another, that residential lighting is not a significant part of your electric bill. More efficient bulbs will eventually save you money, but depending on usage patterns and energy costs, this can take many years. If you want to see significant change in your electric bill, you need to address the major consumers of power. The ...


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