Monday, June 13, 2005

Tips On Saving Money While Using an AC

Courtesy of the Weather Channel online, I am posting information from their website on how to save money and use AC more efficiently during hot summer days. Us New Yorkers know how it is in the city when it's hot AND humid. This has been edited in order to provide relevant info for NYCers who live in apartments, not houses with central AC. We all know how high and expensive the electricity bill can get during hot summer months.

-S


Courtesy of the Weather Channel

Introduction

As the mercury climbs this summer, you don't have to swelter. Learn how to keep your home cool, with tips that will increase indoor comfort and minimize your energy costs.


How Air Conditioners Work

Air conditioners employ the same operating principles and basic components as your home refrigerator. An air conditioner cools your home with a cold indoor coil called the evaporator. The condenser, a hot outdoor coil, releases the collected heat outside. The evaporator and condenser coils are serpentine tubing surrounded by aluminum fins. This tubing is usually made of copper.

A pump, called the compressor, moves a heat transfer fluid (or refrigerant) between the evaporator and the condenser. The pump forces the refrigerant through the circuit of tubing and fins in the coils. The liquid refrigerant evaporates in the indoor evaporator coil, pulling heat out of indoor air and thereby cooling the home. The hot refrigerant gas is pumped outdoors into the condenser where it reverts back to a liquid giving up its heat to the air flowing over the condenser's metal tubing and fins.

Types of Air Conditioners

The basic types of air conditioners are room air conditioners, split-system central air conditioners, and packaged central air conditioners.

Room Air Conditioners
Room air conditioners cool rooms rather than the entire home. If they provide cooling only where they're needed, room air conditioners are less expensive to operate than central units, even though their efficiency is generally lower than that of central air conditioners. Smaller room air conditioners (i.e., those drawing less than 7.5 amps of electricity) can be plugged into any 15- or 20-amp, 115-volt household circuit that is not shared with any other major appliances. Larger room air conditioners (i.e., those drawing more than 7.5 amps) need their own dedicated 115-volt circuit. The largest models require a dedicated 230-volt circuit.

Keep Your Home Cool

Maintain your air conditioner

It's easy to take your air conditioner for granted... until it stops working on a miserably hot day. If possible, have an air conditioning contractor inspect your unit before you start using it each summer. Regular maintenance will not only help spot potential problems, but will also increase the life and energy efficiency of your unit.

What you can do


Clean up around your air conditioner. Outdoor condenser coils can become dirty and blocked, which makes your unit work harder and increases your cooling bill. Your dryer vents, falling leaves, and lawn mower are all potential sources of dirt and debris. Allow for adequate air flow to your unit by cleaning the area around the condenser coil, removing any debris, and trimming foliage back at least 2 feet.

Change your air filter regularly. Check your unit's air filter once a month and clean or replace filters as necessary. Keeping the filter clean can lower your air conditioner's energy consumption by 5% to 15%. Ask your service contractor to show you how to do this, if you aren't familiar with the process.

Keep your condensation line clear. Condensate lines drain away the moisture your air conditioning unit creates. A plugged condensate drain can cause water damage in the house and affect indoor humidity levels. You can help keep the line clear of mold and mildew by pouring in a small amount of household bleach. Ask your service contractor to show you how.

When you hire a service contractor (I doubt we'd ever do this.I think this is for homeowners, but I ain't an expert here.)

When you do your pre-season check, ask the technician to do the following:

- Check for correct amount of refrigerant
- Test for refrigerant leaks using a leak detector
- Capture any refrigerant that must be evacuated from the system, instead of illegally releasing it to the atmosphere
- Check for and seal duct leakage in central systems
- Measure air flow through the evaporator coil
- Verify the correct electric control sequence and make sure that the heating system and cooling system cannot operate simultaneously
- Inspect electric terminals, clean and tighten connections, and apply a non-conductive coating if necessary
- Oil motors and check belts for tightness and wear
- Check the accuracy of the thermostat

Trouble spots

Look out for these things that can compromise cooling power and energy efficiency:

Leaky ductwork. Leakage from areas such as ductwork joints, elbows, and connections can be substantial -- as much as 20% to 30%. This is especially costly if the ducts travel through unheated or uncooled spaces such as attics, basements, or crawl spaces. Use duct tape or caulk to seal ductwork.


Thermostat placement. Don't place lamps or TV sets near your air-conditioning thermostat. The thermostat senses heat from these appliances, which can cause the air conditioner to run longer than necessary. Make sure your thermostat isn't placed in the light of a sunny window.

(I didn't know such thermostats existed! Will keep in back of my mind in case I ever buy a house someday.)

Thermostat abuse. Don't set your thermostat at a colder setting than normal when you turn on your air conditioner. It will not cool your home any faster and could result in excessive cooling and, therefore, unnecessary expense. Install a programmable thermostat so you can automatically reduce the temperatures during low-occupancy hours.


Maximize your cool

(Now, this sounds more relevant! Just what I want to know!)

Be smart about staying cool. These simple tips can help make your home more comfortable and energy-efficient when you're running your air conditioner -- and even when you're not.

Set your thermostat as high as comfortably possible in the summer. When running your air conditioner, set your thermostat at 78°F or higher. Each degree setting below 78° F will increase energy consumption by approximately 8%. The less difference between the indoor and outdoor temperatures, the lower your overall cooling bill will be.

Install programmable thermostats. These inexpensive devices can help optimize your building's heating and cooling needs by automatically reducing the temperatures during low-occupancy hours.

(Have you ever seen a ceiling fan in a real NYC apartment - in our low and middle income class apartments?)

Use a ceiling fan. Ceiling fans create enough air movement in a room to make it feel four degrees cooler or more. When used in conjunction with air conditioning, you can set your thermostat higher than you normally would. The average ceiling fan uses about the same electricity as a 100-watt light bulb (those with the Energy Star label require even less energy), so you can run one for just pennies a day. But only run the fan when you're in the room -- it does not actually make the room cooler; it just makes it feel cooler when you're in the breeze.

Set your ceiling fan for summer. Make sure the blades are turning the right way for summer -- during summertime operation, the high edge of the tilted blade should go forward first, to force air downward. You'll know it's right if you feel the fan blowing down when you stand below it while it's running on high.

Shade your air conditioner. Plant trees or shrubs to shade air-conditioning units, but be sure not to block the airflow. A unit operating in the shade uses as much as 10% less electricity than the same one operating in the sun.

I'd love to do this, but how? It's NYC!

Shade sun-exposed windows and exterior walls. In most areas of the country, direct sunlight streaming through windows during the cooling season can substantially increase your air-conditioning costs. During the cooling season, shade windows with window coverings, awnings, trees, and bushes wherever possible. Exterior shading is more effective than interior shading.

(Mmmmm... maybe we oughta get shades for our windows where the AC is. I oughta get a shade for my own bedroom window which is notorious for turning into a sauna or steamy jungleforest.)

Use bath and kitchen fans sparingly. Avoid using bath and kitchen fans when the air conditioner is operating to avoid pulling warm, moist air into your home.

(So this means not opening the bathroom window to pull in warm moist air?)

Avoid creating heat. When possible, delay heat-generating activities, such as cooking and dishwashing, until evening on hot days.

Seal off unused areas. To reduce heating and cooling bills, seal and turn off the heating or cooling in unused areas such as storage areas.

Repaint building exterior with light colors. When it is time to repaint the exterior or your building, consider using light colors, especially for the roof. Light colors reflect the sun away from the building, thus lowering air-conditioning expenses -- perhaps your largest energy expense.

(Hey, Landlord! Could you paint our brick building??? Just kidding!)

Use fans with your window a.c. unit. Consider using an interior fan in conjunction with your window air conditioner to spread the cooled air more effectively through your room without greatly increasing your power use.


(Argh! Ideal for people with NO allergies. What about folks with allergies? This is a nightmare for people with pollen allergies.)


Sources: U.S. Department of Energy, U.S. Environmental Protection Agency, California Energy Commission