### Image Credits:

1. Alex Wilson

1.
Dec 20, 2012 11:06 AM ET

"training"
by JoeW N GA Zone 3A

Kids learn by watching and through expectations placed on them -- my dad, raised in the Depression, had two mantras, one for lights (If you can turn it on, you can turn it off) and one for doors (You opened it; you shut it). He deducted from allowance and pay (for chores) for each infraction.

In our neighborhood, outside lights provide security. But there's no reason they have to be on all night -- trigger them with motion sensors.

Shut the refrigerator door; shut off its "humidity" detector (which heats the case so condensation doesn't form) and wait to see if condensation forms, then use it for just so long as it takes.

You're running water to clean, not for a massage, nor as a water feature. Just shut it off.

If you garden, invest in drip hoses.

In my climate, adjust the ceiling fan before you turn on the A/C. Leave the windows shut to keep out the humidity. If you want fresh air, go outside.

Yes, I'm cranky, lol. Merry Christmas.

2.
Dec 20, 2012 12:24 PM ET

Math question
by Mike Collignon

Is there a math error in the 2nd paragraph of the section titled "Turn Down The Heat"? I understand 20%/3 = 7%, but where did the 20% come from? I thought the savings, per the previous sentence, was 10%.

Maybe I'm confused.

3.
Dec 20, 2012 12:37 PM ET

Response to Mike Collignon

Mike,
Here's my understanding of the underlying math:

Rule of thumb: Each degree F reduction in the thermostat setting for 24 hours a day results in a 2% savings in your heating energy bill.

A setback of 10 degrees F would therefore result in a 20% savings if the setback lasted for 24 hours a day. If the setback only lasts for 8 hours per day, then your savings are about 7% (about 1/3 of 20%).

This is rough-and-ready "napkin math." Take it with a grain of salt.

4.
Dec 20, 2012 1:16 PM ET

Set-back savings
by Alex Wilson

Yes, Martin is correct on the math--and correct that we should take that with a grain of salt. Those assumptions are for an average house. With a highly energy-efficient house, I think the effect would be quite different.

5.
Dec 20, 2012 3:14 PM ET

other suggestions
by Kathleen Mitchell

Turn the heat down a couple of degrees every month and every year - you will get used to 63 degrees pretty easily (though slowly - it might take a couple of years). Wear long underwear and a sweater all the time.

Turn the heat down to 50 degrees at night.

Keep your refrigerator and freezer full.

Slowly train yourself to get used to lower light levels indoors.

Go to bed earlier.

Turn the TV and computer off when you're not looking at them.

Use power strips for computers, TVs, etc. Keep them off when you're not using the device.

Don't shower if your hair isn't greasy: wash yourself at the sink with a washcloth.

6.
Dec 20, 2012 3:43 PM ET

Thanks
by Mike Collignon

I see where I made my error. I read the second set of numbers as 72-67, not as they were written (72-62). Sorry about that.

That's what I get for speed reading.

7.
Dec 21, 2012 12:02 AM ET

My first "super" insulated
by Richard Patterman

My first "super" insulated house twenty years ago, the clients had very high utility bills. I went to trouble shoot the problem and they had the A/C set at 70 and the heat set at 69, one or the other was running most of the time. I realized I needed to "train" clients and discuss expectations.

In a typical two story with with master bathroom up and DHW in the basement, washing your hands with hot water uses 3 plus gallons of hot water. A little bit of thought and you realize soap and cold water works just fine.

This time of year when doing my evening walk, I am amazed at the number of houses with bright lights in every room in the house. I've never seen the need to light rooms that are not in use.

8.
Dec 21, 2012 6:51 PM ET

Edited Dec 21, 2012 7:01 PM ET.

Myth busting about closing off registers and setbacks...
by Dana Dorsett

Closing off vents to unused rooms INCREASES rather than decreases energy use, as counter-intuitive as that might seem. Increased duct pressures and lower system balance driving higher whole-house infiltration rates is the culprit. Air sealing ducts & house may lower the magnitude, but not the direction of the change in energy use.

----------------------------------

According to a 2003 study by the Lawrence Berkeley National Laboratory:

"Closing registers in forced-air heating systems and leaving some rooms in a house unconditioned has been suggested as a method of quickly saving energy for California consumers. This study combined laboratory measurements of the changes in duct leakage as registers are closed together with modeling techniques to estimate the changes in energy use attributed to closing registers.

"The results of this study showed that register closing led to increased energy use for a typical California house over a wide combination of climate, duct leakage, and number of closed registers. The reduction in building thermal loads due to conditioning only a part of the house was offset by increased duct system losses, mostly due to increased duct leakage. Therefore, the register closing technique is not recommended as a viable energy saving strategy for California houses with ducts located outside conditioned space.

"The energy penalty associated with the register closing technique was found to be minimized if registers farthest from the air handler are closed first because this tends to only affect the pressures and air leakage for the closed off branch. Closing registers nearer the air handler tends to increase the pressures and air leakage for the whole system.

-----------------------------------

I couldn't find the original LBL study online ("Register Closing Effects of Forced Air Heating System Performance." Walker, I S. ) but it's out there, and widely referenced in other academic research on the topic.

The overnight thermostat setback issue is also not universal. With modulating heating systems such as ductless mini-splits or modulating condensing boilers under "outdoor reset" control, overnight setbacks force the systems to run at dramatically lower efficiency during the recovery ramp periods, erasing any savings, and sometimes significantly increasing total energy use. (This is not the case with most condensing gas furnaces or non-condensing hydronic boiler systems.)

Only with setback periods much longer than 8-10hours would any energy be saved with a mini-split air source heat pumps, since running at max-power during a recovery period they only run at 50-70% the efficiency as when modulating with load. This varies with outdoor temp and actual overnight load, but a 30-50% hit in efficiency is a reasonable approximation for most real-world installations. See figure 5 on p.10 (p.18 in pdf pagination) of this document:

http://www.nrel.gov/docs/fy11osti/52175.pdf

The lower heat loss due to the lower temperature in the house over night is nowhere near as big a gain as the hit in recovery efficiency when warming it back up- it's a net loss. "Set and forget" is a much better strategy with these systems unless you're taking off for the weekend.

9.
Dec 21, 2012 7:56 PM ET

Response to Dana Doresett

Dana,
I agree with you. GBA already reported on that study in a previous article: More Energy Myths.

10.
Dec 21, 2012 9:26 PM ET

Edited Dec 21, 2012 9:39 PM ET.

Fill dead air space in freezers/refrigerators
by Jonathan Teller-Elsberg

A comment above recommended keeping a full refrigerator or freezer. If you find you often have a fair bit of free space, consider downsizing your fridge/freezer. In the meantime, you can fill empty space with either jugs of water, empty shoe boxes or similar, or bags full of styrofoam peanuts that you otherwise have no use for. All of them help by preventing large volumes of chilled air from falling out of the appliance (assuming an upright model) when you open the door, so that the appliance doesn't have to chill new, warm air. It's possible that the jugs of water help the most by adding a thermal mass advantage.

We have a second freezer in the basement which gets loaded up in autumn with garden surplus. As the winter goes by and it starts to empty out, in go the shoe boxes to take the place of the veggies.

UPDATE: oops. I just followed Martin's link and (re)read his More Energy Myths post from a year ago. It lists filling up refrigerators as one of those energy saving myths. Alas.

11.
Dec 21, 2012 9:33 PM ET

Use winter to pre-cool leftovers
by Jonathan Teller-Elsberg

Another thought... before putting leftovers into the refrigerator, let them cool down. We are in the happy situation of living in a quiet, small town, so we will put a pot of hot leftovers on the stoop in cooler weather to chill it before moving it to the refrigerator. (I wouldn't have done that when I used to live in Washington DC, even assuming I had the get-up-and-go to walk down 5 floors to the apartment building front door.) When the food in question has been cooked and is still in our pressure cooker (which has a locking lid), we'll just leave it on the stoop all night in winter. The basically air-tight lid prevents odors from attracting animals--at least, we've never seen evidence of animals trying to get in.

Pressure cookers! If you have one and don't use it, then that there is a great behavior change to aim for. They'll save you energy while you cook, and as we've learned with the trick above, save you more when the food is finished and ready to store.

12.
Dec 22, 2012 10:27 AM ET

by JoeW N GA Zone 3A

Letting the weather be your friend when it's as cool outdoors as it is in your refrig makes good sense but the notion of pre-cooling when warm food is brought down to room temp on the kitchen counter can become a medical issue, as once the food holds a temp that will allow bacteria, etc to flourish, you may create intestinal issues, maybe serious!

I once had a neighbor raccoon decide the goodies cooling on my porch were really appetizing .... but that's another story.

13.
Dec 22, 2012 11:38 PM ET

Thermostat setback math, dishwashers, clothes dryers
by Curt Kinder

I agree with Dana's comments as to the efficiency of various types of heating systems operating at higher outputs during recovery periods. Some systems are more efficient if this is avoided, others, particularly constant output systems, do better with long on-cycles, somewhat like highway driving.

Then there is the issue of savings from the setback itself. Setback only saves after the home has partly or wholly cooled down to the setback temperature, reducing the temperature gradient across windows, doors, and exterior walls. A tight house may not cool much during the first few hours of a setback, so will not deliver much savings.

A note on dishwashers - many have a "quick wash" cycle that takes just 30-40 minutes and uses far less energy than a full 90+ minute cycle. Ours delivers satisfactory results with the quick cycle if the machine is 2/3 - 3/4 full. In other words, it'll clean a half load for 1/3 energy, so we come out ahead using that mode.

OTOH, clothes dryers seem to work differently. I'm gathering experimental data on loads of laundry - I have a TED monitoring channel on our clothes dryer and I'm using a refrigerant cylinder scale to weigh wash loads before and after drying so as to calculate pounds of moisture removed per kiloWatthour.

Preliminary data suggests the dryer runs most efficiently (upwards of 2.0 lbs / kWh) with fairly heavy loads using the "casual" (between "normal" and "delicate" temperature profiles). A couple of times I've combined two medium sized wash loads in a single dryer cycle, which has yielded best efficiency without significantly lengthening drying time or lint production.

14.
Jan 1, 2013 7:31 PM ET