Save some energy
No matter what you think about global warming, saving some energy makes sense, especially when it comes to saving money. Being a meteorology person, I’ve come up with some common sense ways of saving energy, from electricity to gasoline. Some of these I’ve heard from others.
1. Let in cool air when it’s available. Nights like tonight, when it could easily be in the 60s before 10 pm, think about letting the outside air cool your home. If you have window screens or even screen doors, and there are no issues with outside air (allergies, pollution), opening up the windows for an hour or so before going to bed can eliminate the need for air conditioning on a night like this, and if your house cools down enough, it may also reduce your need for air conditioning the next day. This works on a lot of nights in April and October.
2. On hot days, close the blinds and/or curtains on south-facing windows before you leave for work. This keeps solar radiation from heating your home like it does your car.
3. Even if you don’t have a thermostat with a timer, turn it up a little, even 2 or 3 degrees, while you’re gone to work. This will keep it from coming on for a while, and once it does, it won’t have to run as much. The heat coming into your home is proportional to the temperature difference between your home and the outside air. So, when it’s 95 outside, your air conditioning will only have to run 75% as much when your house is 80 as it does when your house is 75.
The idea that it will have to run just as much overall to catch up when you get home is not thermodynamically sound.
4. Cook outside more on hot days. All that heat produced by your oven or range has to be removed by the air conditioner.
5. Run the exhaust fan (if you have one) in the bathroom while taking a shower, and in the kitchen while cooking indoors. Moisture condenses in your air conditioner and releases latent heat, so the drier the air is in your house, the less it has to run to maintain the same temperature.
6. Use the hair dryer sparingly on hot days.
7. Close off unused rooms and close the vents. As pointed out by Don Hooks, father-in-law and engineer, closing off 25% of your house won’t reduce your cooling bill by 25%, since there is no insulation between rooms, but it will still reduce your cooling bill somewhat (maybe 15% or so).
8. Try to only run the dishwasher and clothes washer when they are fairly full.
9. Drive a little slower. The air resistance on your vehicle, which is one of the main factors that causes fuel usage once you’re at a constant speed, is proportional to the square of the air speed. So, you get 60% more air resistance at 70 mph than at 55 mph, even though you’re only going 27% faster.
10. Limit use of drive throughs at banks and fast food places. Sitting in line for 10 minutes with the engine and air conditioning running burns a significant amount of gasoline.
11. Roll the windows down and let the 150 degree air out of your car when you first get in. This limits the load on the air conditioner, and saves gasoline.
If you have any other ideas to save gasoline or energy, comment!
June 18th, 2008 at 12:39 pm
Walk, ride bikes, car pool, public transportation…slow down, meet new folks and enjoy the day instead of always having to be in control, rushing (in traffic?)…life’s too short to squander.
June 18th, 2008 at 12:39 pm
When leaving the house for more than a couple of hours, turn up the thermostat (or if you have a programmable one, program it to go up) during the day. We keep the A/C on 75 when we’re home in the daytime, and even cooler at night, but always turn it up to 80 when we leave the house for the day. By evening when we get home, it is cool enough outside that cooling the house back off doesn’t take that long.
Also, when driving your car, try anticipating and coasting to stoplights. And, there’s no need to rocket from redlight to redlight. Keeping the RPMs under a reasonable amount (in my 4-cylinder Honda Accord I do my best to stay under 2,500 RPM except when merging on the freeway) will help save fuel and your brakes!
June 18th, 2008 at 12:43 pm
Great post, Tim! At the risk of sounding eccentric I have found great benefit by doing several of these. I live in an old house that is shaded by oak trees that are over 100 years old. Since I work in the day and have been out of town a lot I have not yet had to use my air conditioner at home. Last night I was actually very comfortable. It was a little on the cool side with my window fan blowing in 58 degree air this morning. I would suggest planting some fast growing maple trees in strategic areas to provide shade to the south and west side of your home.
The driving 55 idea is really good. How many people gripe about the price of gas while driving their SUV or huge truck down the road at 80+ miles per hour? I have seen a great difference in fuel economy by leaving early and driving slower. Like many cars do these days, my vehicle has an automatic fuel economy meter. I have found that I average 28 miles per hour going 55 but only 21 if I drive 75.
I drove to the coast last week at 55 to 60 mph. Based on the distance I traveled round trip (about 700 miles) I estimate that I saved about $33 in gasoline cost, paying $97 instead of $130. Besides saving energy it paid for our family to eat at Lamberts and catch some of those throwed rolls!
June 18th, 2008 at 12:53 pm
Hello Tim,
Good comments. I’d like to comment on a couple of your comments.
No.1: This is a great way to pre-cool your house for the next day. It is especially good for the west and north sides of your house, that won’t see sun for several hours.
No. 2: This is somewhat true. Unless the shades are on the outside, the solar energy will still enter your house. Some of it will reflect back out through the glass, but some of it will stay in. Blinds/curtains do keep the objects in your house from heating up as much, but some of the load is still seen by the AC unit.
No. 3: This is true, but it will take a while to cool your house down from 80 to 74 or whatever you like it at, especially in a humid climate. The total run time will be less and you will save energy (money). The time of highest load in your house or a building is usually in the evenings, around 5:00 or 6:00, or even later in some cases. The mass of the structure heats up and radiates the heat hours after the “hottest” part of the day.
No. 7: Be careful that you don’t close off too much of your house, because your cooling coil will freeze up if the airflow across it gets too low. Then you have to turn it off and let it thaw.
June 18th, 2008 at 1:11 pm
Dr.Coleman,
If you don’t have an attic fan I would suggest going to somewhere like Lowe’s and buying one. Their inexpensive and on a night like last night as well as tonight you can open your windows turn the fan on and cool your house in about 10 minutes. Then you can close your windows and enjoy the fresh cool air the fan pulled in. Also in some areas where radon is high you can you use the fan to flush air out of your house and bring in fresh air in a timely manner. By the way since I mentioned radon it’s a good idea to test your home for it. You can find the test kits at Lowe’s or Home Depot. From what I understand airing out your home every so often is the best defense against radon gas if it is present in your residence.
Question: On tip #9 that you gave about driving and air resistance, does that apply to all vehicles i.e. a small car compared to a large SUV? It seems obvious the smaller car would receive much less air resistance.
As always thanks for sharing your knowledge! Take Care
June 18th, 2008 at 2:39 pm
The attic fan is a classic..many homes when I was growing up and in my early 20′s didn’t have central heat/air so the attic fan was the only means of cooling.
Today most homes are well insulated and an attic ventilator or more depending on house square footage are a great energy saver. We have two that are electric power yet thermostatically controlled. They use about like a ceiling fan watts wise and kick in when the temp in the attic reaches 90 degrees which is pretty early on hot days. Even the whirlybird types (not electrically controlled) give savings.
Ceiling fans are also a energy saver, all ours can be reveresed depending on the season. They run all the time in just about every room during the hotter times keeping the air inside moving as well as any occupants cool during the day and night. During the winter it keeps the warmer air pushed down toward the folks inside making us at least feel warmer!
Good tips one and all…stay cool!
June 18th, 2008 at 3:11 pm
Great tips. I found a few more ideas I could use. I now keep one side of my kitchen curtains closed, so the heat from the afternoon sun doesn’t heat up my kitchen and the reflection off my concrete patio. I also have my spare bedroom vent closed off since I am rarely in there, and also my spare bathroom, since nobody uses it either. I bought those magnetic placemat type things to cover the vents. I have also only had my A/C on around 78° both day when I am at work and night, and it is fairly comfortable for me. I actually turned my A/C up last night, and left a window open today to let some fresh air circulate thru the house while it is still cool. Thanks for the other tips Tim.
June 18th, 2008 at 3:34 pm
michelle m,
Make sure you read Matt Marshall’s post about 3 post up from your’s. He is a true pro on this subject. You may want to be careful about covering so many vents. Just trying to help. Have a good day and thanks for your comments.
June 18th, 2008 at 5:32 pm
Well I want to say something about turning your A/C up when you leave during the day. If you leave your unit on 75 when that temperature is reached it will hold it there. and the A/C will cycle off and on I know this is true because my brother has his on 75 and he never changes it it stayes on that temperature. If you turn the unit up to 80 or so well the house get’s hot so when you come home the A/C has to work hard to pull the temperature down and that means the walls the floor it has to cool that stuff down before the air get’s cool. Why do you think when someones A/C goes out in the summer and the don’t get it back on untill late and the unit runs for ever before it shuts off? well that is because everything in the house is hot and it has to cool that stuff off before it can turn off. So I would just leave the thing set and don’t touch it thermostats are made to be set and not touched if the unit is running great it will keep the temperature where you set it.
June 18th, 2008 at 10:08 pm
michael, the reason you turn the A/C temp up is this …. you save energy for say 8 hours while your away, and it takes maybe a no hour or two to cool it off the two degrees you raised it.. You don’t shut it off completely or yes, you would run into the issue of having to cool down a stifling house. We’re talking at highest turn it to 80 degrees .. That’s still 10-15 maybe 20 degrees cooler than the outside ..’ve done this myself and shaved $30 off my monthly power bill.
June 19th, 2008 at 7:34 am
Here some other tips on saving energy:
1. Move your thermostat to the warmest part of the house. You can turn it up a good bit, and the rest of your house stays cooler for the most part. When the air is off for a while, the other rooms might get 2 or 3 degrees above your thermostat before the air comes on. Otherwise, all the other rooms are cooler than where the thermostat is. It seems to not come on a whole lot at night, even in the warmest of night.
2. Put a ridge vent in the roof. Hot air that normally would be trapped in the attic rises out the vent and out of your home. However, you need to make sure that the builder that puts a ridge vent in an old roof does it right, or you may have issues with the roof.
July 20th, 2008 at 4:15 am
[...] Remember to drink plenty of water, and limit time outdoors between noon and 4 pm. For tips on lowering energy costs during these hot days, click here. [...]
July 20th, 2008 at 5:37 am
another thing I’ve started doing is using the old line to hang wet clothes on outside …. they dry fairly quickly on the toasty days, feel better when u wear um, and that dern clothes dryer heats up my house as well as eats up the power like there’s no tomorrow ..
few other things:
reinsulate around the door frames after a few years the insulation get old and doesnt work as well….
get thick dark curtains .. and use them!
try using a few window units versus a central unit if you’re not going to be using the entire span of your building for a while
use the fluoroescent bulbs …ive had these for a long time and they’ve yet to go out, and they dont make hardly any heat at all like incandescants do.
if u live in a trailer, and ive done this to amazing success in the past, on hot summer days run a soaker hose along the roof and turn it on so that the water completely evaporates just before it falls off .. no more no less…i dunno if this will work on a house, but Im tempted to try it … if you have a tin roof I’d almost bet it would work ..
If its not too hot, crack a window and shut the AC off in your vehicle … (no the drag the open window causes is not enough to make up for the ac being off)
Turn off any appliances or what not that have a standby mode or a digital display of sorts …. these items can cumulatively eat up alot of energy …like computers etc, they may be saving energy in comparison to running full sprint, but not like they would if they were shut off … I’ve also heard that the newer LCD screens use alot less power than old school CRT, which makes darn good sense so let’s upgrade those monitors! lol
October 22nd, 2009 at 3:10 am
[...] generally a good thing. It reduces pollution and saves me money. I have written on saving energy (click here.). I plan to do the same for winter. Also, do you really need a giant SUV to tote your kids around [...]
November 1st, 2009 at 9:44 pm
Excellent common sense advice . . . but some of which I hadn’t thought of. The only thing I’d add has already been said, and that’s the idea of actually walking to places instead of always driving – within reason, of course. I loved how Lewis Grizzard wrote in one of his books that if more people walked like they did when he was a kid, it wouldn’t be such a big deal when some “sheik of the burning sand” decided to cause a ruckus over the oil. He was being funny, but it was a good point I thought. Modern technology/conveniences are nice – but they’re even nicer when used wisely. Anyway just have to give kudos to a Ph.D. who is obviously just as strong in the “good ole’ horse sense” department.