Ask Umbra’s video advice on beating the heat 8

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1. 

   Bill Hewitt Posted 11:34 am
   29 Jul 2009

   How Uncool is AC?

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2. 

   sindark Posted 2:42 pm
   29 Jul 2009

   Are the ice cubes really a good idea? How much energy gets used in freezing them, compared with getting the same amount of cooling with air conditioning? Thermodynamically, may take more energy to cool room temperature water towards zero degrees than it takes to cool air from the ambient temperature outside to an acceptable one inside, though the ice-air current might be a lot more targeted than universal AC...

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   1. 

      infernoii Posted 4:55 pm
      29 Jul 2009

      Isn't your freezer on anyway???

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3. 

   Louie Posted 6:37 pm
   29 Jul 2009

   Well. I guess those are pretty good tips if you live in a mild-weather area, like San Francisco Bay Area. I live in Texas, though, and today and tomorrow it's going to be a cool 104 degrees. At night it certainly cools off, to the high 80s. There's no way you can do without AC in your home, your car, your workplace. You could use all the ice cubes in the world, and you'd still be heat struck. There's really no alternative, and the summer lasts from late April/May to mid-November, though I've had to have the AC on around Christmas many years because of the awful humidity.

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   1. 

      mtvyfan Posted 9:22 am
      30 Jul 2009

      As a former Houston resident (ewww, don't miss it) and also former Austin resident (HOOK 'EM HORNS!, Austin ROCKS!) I totally agree with you Louie. Summer is pretty much the only season in Texas. I remember living in the winter in Houston and the humidity made it feel colder than where I live currently, in Montana. AC is a requirement. Without it, I remember growing up and everyone having their drapes drawn so that it felt like you were underground. Remember that, Louie? Then dying with a wet wool blanket on when you left home. Ahhh memories.....

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4. 

   llime Posted 11:35 am
   01 Aug 2009

   I don't know how using a rigged up air conditioner with ice cubes and a fan could be more efficient than using an actual air conditioner. The ice cubes will increase the humidity of the air in the room. An essential component of an air conditioner is a drier to remove moisture from the air. As for the question of isn't the freezer already on : no, the freezer cycles on and off to cool the warm things put in to it. If there was such a thing as free ice, we wouldn't be having this conversation.Running a fan in a relatively cool room will increase the rate at which it is heated by the surrounding warmer air. Air movement increases the rate of heat transfer. If air is blown across an interior wall this will increase the rate of heat conduction through the wall. In still air, the warmer air will be at the top or next to the ceiling of a room. A ceiling fan is good if you want to move warm air down to where you are but a bad idea if you want to stay cool. If there is a hot attic above the ceiling, a ceiling fan will help cool the attic at the expense of the room. During the day, a fan is only useful if the room is already at the same temperature as the outside and you want the air movement to evaporate perspiration from your body (which will increase the humidity of the room).At night, fans should be used to move the relatively warm air in the room to the outside. A fan has an inlet and an outlet and should be thoughtfully placed to move air from one place to another. The exhaust fans that are used in kitchens and bathrooms can be used to cool a living space at night. Fans are available that move more air with less noise than standard, low cost fans. The hot roof will cause air to rise, facilitating the exhaust of air from the roof vent. The fan's inlet is on the ceiling where the warmest air is. This air will be replaced be the cooler air coming in through open windows. To maximize the air flow through the living space, the open window should not be in the same room as the fan.

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5. 

   ohiopapa Posted 4:54 am
   04 Aug 2009

   I've tried to keep the whole house cool by heeding Steven Chu's advice, and painted the back-facing roof with some left-over white paint (I imagine exterior would work best). It has dropped the inside temperature a few degrees, and I look forward to a drop in our electric bill. Why not try it yourself?

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6. 

   sanseref Posted 8:44 pm
   04 Aug 2009

   Even if you need to have the AC on, closing curtains and having fans on can help so that you can have a higher temperature on your AC. Many times, I will use the AC only to help dehumidify the air.I have window units and can therefore only turn the AC on in the rooms I am hanging out in. I also buy AC units that have energy conservation and will turn all the way off once they reach the set temp.

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