Summer just around the corner, huh? Is your house ready? Here are frugal tips to keep your house cooler over those summer months …

It's hot and muggy where we live during the summer. Maybe for you too!
I know that we really depend on our air conditioning to stay comfortable, but we pay for it.
Here are a bunch of frugal tips that hopefully will help you to pay a bit less to keep your house or apartment cool during those hot summer months.
1. Use nature's air conditioning
Air conditioning has only been around since the turn of the 20th century. Willis Carrier invented the first modern air conditioning system in 1902.
What did people do to cool off before air conditioning? They opened the windows!
We also can use portable or ceiling fans instead of cranking on the air conditioner.
The trick is the air movement. Even air movement as gentle as 1 mile per hour can make you feel a few degrees cooler. Make sure your ceiling fan is spinning in the correct direction. The air should blow downward so that you can take advantage of the “wind chill effect.”
One thing to bear in mind, though, if you open the windows during the hottest part of the day, you're bringing in the hottest air of the day as well, so it might actually be better to shut in the house and keep it shut in until the temperature of the air outside goes below the temperature of the air inside. This is especially true of the upper levels of multi-story houses.
2. Give your air conditioner an assist
We're in the 21st century now. We don't always have to pretend like we're in the 19th century. There's, of course, no shame in turning on that window unit.
You can, however, use another fan with your window unit to spread that cool air through your home a bit more. This supplements the one that's already in the unit. A stand-alone fan will usually be better at being a fan than the one in your unit.A helper fan supplements the one already in the air conditioner.
3. A clean filter is a happy filter
Filters filter stuff. Air filters filter stuff out of the air. (And you're thinking: “Thank you, Dr. Seuss!”)
A dirty air filter makes the compressor work harder because all of the small holes in the filter are clogged with stuff. Change the air filters every month during the summer when the air conditioner is in use. This is a good way to reduce air conditioning costs.

4. Don't turn the AC off completely
Although an air conditioner that's shut off doesn't use energy, it's probably not the best-balanced solution for saving money on cooling. It looks like one of those frugal tips, but it isn't!
Instead, bump the thermostat up seven to ten degrees when no one is in the house. (Or, use a programmable thermostat to do the same.)
This keeps the humidity inside more manageable because the AC does kick on, just not as often. That means less mold and fewer creepy crawlies.
Further, because the temperature inside gets closer to the temperature outside, it doesn't take as much energy to lower the temperature.
5. Don't psych out the thermostat
Thermostats react to temperature changes near a sensor, which is usually inside the control unit. As such, it only really “knows” about the temperature immediately around it.
Don't place electric things that put out a lot of heat near your air conditioning thermostat. The extra heat from these appliances makes the air conditioner run longer because the thermostat thinks the surrounding air is hotter than it actually is.
Though we don't have as many cathode-ray TVs and incandescent light bulbs as we used to — both of which put out a ton of heat — other appliances can still put out a lot of heat.

6. Regarding incandescent bulbs …
Incandescent light bulbs are the “old style” Thomas Edison kind of light bulb that works by passing an electric current through a metal filament.
They put out light, but they also put out a lot of heat, too. (The filament gets up to over 2,000 degrees Fahrenheit, after all!) Replacing incandescent bulbs with newer light-emitting diode (LED) bulbs will not only decrease the heat in the room but will also provide electricity savings on the bulbs themselves.
LED light bulbs were pricey ten or fifteen years ago, but not anymore. Just be sure that the bulbs are marked “dimmable” if they need to be.
7. White shades are where it's at
Quick physics lesson. If light hits something, that light does one of three things. It (a) goes through (is transmitted), (b) bounces back (is reflected), or (c) gets caught inside (is absorbed).
Installing white shades, blinds, or drapes will reflect more away from the house than equivalent black shades, blinds, or drapes. The black versions will absorb more, and will heat up more.
8. Watch those hot appliances
Some of those kitchen gadgets run hotter than others. Be more choosy when you run them.
Consider letting your dishes air-dry instead of using the drying cycle (assuming your dishwasher has one). It just takes a little longer.
Also, consider using a microwave oven instead of a conventional electric range or oven. This may mean adjusting what you prepare for meals if it's not microwave-friendly. Or, pick cooler-than-average nights to bake something. Or use a toaster oven rather than the full-size oven.

9. And hot non-appliances, too
Some of the worst offenders for putting out heat are consumer electronics. Computers especially put out a lot of heat. The chipsets that run modern computers run in the neighborhood of 80 to 100 watts. That's the same power as a bright incandescent light bulb.
Also consider plugging in other electronics like TVs, tuners, DVD players, etc., into surge protectors, and turning the power strips off when equipment is not in use. These guys aren't really “off” because you need to supply energy to the device to be able to turn it on with a remote.
10. Less hot water = less heat
Water has a very high capacity for heat. Heat it up, and it retains the heat for a long time.
Though most of the heat in your water heater stays there because of good insulation (right?) you might consider lowering the thermostat on your water heater to 115 degrees Fahrenheit. That temperature is comfortable for most uses.
Similarly, consider reducing your hot water usage by taking (reasonable-length) showers rather than baths to reduce hot water use.
Also, wash dishes only when the dishwasher is full, and only full loads of clothes. Anything to reduce the amount of steam entering the main area of the house.
11. Plug those holes up!
It's no secret that holes or cracks in your house hurt your energy efficiency. Heat flows naturally from hot to cold; the hot outside air naturally wants to come into a cooler house.
Adding weatherstripping and caulking around places where heat can get in will help to keep your house cool during the summer.
If you see separated joints or holes in ducts, though, look into professional repairs unless you really, really know what you're doing.
Consider adding insulation around air conditioning ducts that are located in crawl spaces, attics, and garages. Similarly, do this for whole-house fans in the places where they open to the outside, or to an unconditioned attic. Metal ducts are excellent conductors of heat, so you lose a lot of the benefits of the air conditioning if the air travels through uninsulated metal ducting.