Record temperatures are creating uncomfortable conditions all over. Here in Pennsylvania, we’re expecting near 100F temperatures for much of this week, while Chicago just suffered through a heat index of 115F!
Along with high temperatures come big utility bills because of all the air conditioner usage. In this post, I’ll give you some tips for how you can “beat the heat” without breaking the bank!
Why Things Get Hot
If you’ve read any of my posts, you know that I like explaining things because I want you to understand WHY things occur. Once you know why, you can figure out solutions yourself.
Why do we use umbrellas to block the Sun? We all know that it’s cooler in the shade because the sun radiates heat. So if you can block the solar radiation, you can block a lot of the heat that it brings.
Even if you’re in the shade, it can get darned hot! If you’re sitting in your house, you’re being shaded by the roof – no direct sun is hitting you yet you’re still hot. Why? Because there’s still a lot of heat coming in – from the hot roof, the walls, sun shining through the windows and hot air entering the house.
There are other things that heat your house in the summer. Some obvious, some unexpected. You probably know that conventional light bulbs put out a lot of heat. In fact, each light bulb acts like a little space heater. But did you know that every appliance in your home, from your television to your refrigerator, is also pumping heat into the house 24-hours a day? And your water heater, especially if you have an oil boiler for your hot water – those throw off a ton of heat!
Quick recap -houses get hot in the summer because:
- Solar radiation heats objects in direct sunlight, like your roof
- Hot air carries heat directly into your house
- Hot air and solar radiation heat your walls
- Solar radiation enters through windows and skylights
- Appliances and lights produce waste heat that enters your home
Beat the Heat!
Now that you know what causes your house to get hot, let’s see what you can do about it. I’ll start with the easy ones and work up to ideas that require more changes or greater investments.
- Wear light clothes. Ok, this one is so obvious that I’m embarrassed to write it! But simple things like shorts, a lightweight shirt and no socks make a big difference to your comfort level.
- Drink ice water or other no-calorie drinks. Cold drinks help reduce your body core temperature, that’s good. But don’t drink beer or soda or eat ice-cream and expect to stay cold. Anything with calories adds energy to your body, and that energy makes you less comfortable in hot weather.
- Use fans to circulate air around you, but only when you’re in the room. Fans cool you by speeding the evaporation of sweat and by carrying heat away from your body. But when you leave the room, turn off the fans or you’ll be wasting electricity AND adding heat to the air because the fan motor gets hot. Remember – fans do not cool the air!
- Turn up the temperature on your air conditioner. A slight increase in the temperature setting of your AC results in a significant reduction in the amount it runs. For example, raising the setting from 72 to 76 can reduce the energy use by 25%. Use a fan and turn up the temperature and you’ll see the savings on your next utility bill.
- Raise the temperature on your AC when you’re not at home. There’s a lot of debate on this one, but let me put it to rest – you save considerable energy by turning up your AC when you’re not at home. Yes, you have to crank the AC when you get home, but there is definitely a savings – you will save much more energy doing this than leaving the AC at a constant temperature all the time.
- Open the windows at night only if it’s cool and dry. Natural cooling at night is a great way to cool the house only when the air is dry. A big use of air conditioning is to remove moisture from the air so if you open your windows at night or in the morning when it’s really humid out, you’re filling your home with water. After that, your air conditioner has to work overtime to remove that moisture. So resist the temptation to open up the house when the humidity is high.
- Turn off lights when you’re not in the room. This is always good advice, but it makes even more sense when it’s hot out. Remember, those lights are little space heaters. The longer they burn, the more your air conditioner has to run to remove the heat that the lights put out.
- Replace lights with high-efficiency bulbs. This requires a little investment but it pays off year round. Compact fluorescent and LED bulbs are much more efficient than conventional bulbs mostly because they convert more of the electricity into light. I’ve written more than enough about the direct energy savings from these bulbs. Stop making excuses and replace those bulbs!
- Install a new fridge. And recycle your old refrigerator. The old energy hogs throw off an amazing amount of heat. A new, super-efficient fridge can pay for itself in a few years and it will heat your house less.
- Add insulation to your attic. If you don’t have at least a foot of insulation in your attic, you’re probably under-insulated. If you have a house from before the 1980’s, chances are, you only have a few inches of insulation. Going from 3 inches to the recommended 14″ of insulation (maybe R-9 to R-42) will reduce the amount of heat moving from your attic into your home by about 80%. A good insulation job is something you’ll appreciate year round.
- Shade your windows. Remember, a big reason things get hot is because of sunlight. Ideally, you don’t want direct sunlight entering the windows. The best way is by using trees or bushes to shade the windows. If that’s not possible, exterior awnings do a great job, though many people object to the aesthetics. If that’s you, then get interior cellular shades to block the direct light.
- Get windows with heat reflective coatings. In recent years, window coatings have gotten truly amazing. A good window can block 90% of the heat from entering from the sunlight. This also protects your carpets from damaging UV radiation. An added benefit is that these same windows will hold in more heat during the winter and they’ll be less drafty. So replacing old, leaky, single-glazed windows with tight, low-e, double or triple-glazed windows can make a big difference in your comfort year round.
- Install a white-roof. Depending on your climate and your current insulation, this may or may not make sense. If you have lots of insulation, than the amount of heat coming in from your roof can make very little difference. But if you’re changing your roof anyway, get a reflective roof. This can substantially reduce attic temperatures and therefore the heat entering your home.
- Install a more efficient air conditioner. New air conditioning is usually my last recommendation. You’ll spend thousands of dollars and depending on where you live, you’ll may only use it a few months per year. However, if you have an old unit, it’s probably operating at less than SEER 10, so switching to a new SEER 18 unit can cut your AC bills nearly in half.