Does Running Your Car's Air Conditioner Really Affect Gas Mileage

When it gets warm outside, your air conditioner becomes your best friend. This is most definitely true in your car, where temperatures can sky rocket to 170 degrees under direct sunlight. But most people these days are under the impression that the more you run your air conditioner the more gas your car will guzzle. Now that gas prices are higher than the cost to eat at McDonald's, people are starting to take precautions and do what they can to help with their cars fuel economy. The assumption that running your air conditioner burns way more gas is somewhat untrue. Leaving your air conditioner off makes barely any difference in the amount of gas you burn. With the advent of modern, more fuel efficient cars, this myth is busted!

The air conditioner draws its power from the engine which uses some gas, but with today's cars, this use of gas is minute. The air conditioner can decrease the fuel economy of your car up to 20% in some vehicles, but it depends on the type. Driving with the air conditioner is more fuel efficient than driving with the windows down. Driving with the windows down creates drag which means that your engine has to work harder to keep your car at the current speed; this burns more gas than if you just ran your air conditioner.

In the long run, using your air conditioner is far better than any other means of cooling yourself off in the car, unless you're driving in traffic. When you drive in traffic you aren't going very fast so the drag on the car is minimal. In these cases, you burn more fuel running the air conditioner than having the windows down. That makes sense. When you drive on the highway you can use either the air conditioner or the "window down" method to cool yourself, because, honestly, there is no noticeable difference in gas usage at those speeds.

Here are some tips about you and the heat in your car. Before you get into a hot car, roll down the windows and let it air out. There is nothing worse than getting into a hot car, sitting on a lava hot seat, touching a super hot steering wheel, and breathing stuffy super heated air. Your car needs some time to cool down for itself and for you. Once you believe it is cool enough to actually sit on the seat, turn on the car and run the air conditioner on recirculation. This will help the car cool down much quicker, and you can be on the road fast without sacrificing a layer of your precious skin.

So now that you know the air conditioner can be your fuel efficient friend, maybe you won't be so quick to turn it off or ignore it in favor off putting the windows down and choking on bugs. The air conditioner in your car burns much less gas than your window method, so give your air conditioner a chance and be cool in the heat.

Gregg Hall is an author living in Navarre Beach, Florida. Find more about this as well as a car wax at www.carcarewizards.com

Updating Your HVAC System

The shock of skyrocketing utilities bills may have you thinking about upgrading your HVAC system?. and rightly so, because there is no chance the fuel costs are going to go down.

The newer heating and air conditioner systems are much more efficient than older units and offer significant long-term energy savings. The Government has mandated that any cooling units should have a SEER rating of at least 13 starting in 2006 and this is good, because a twenty-year unit may have a SEER rating of only 7 or 8. However, for real savings you should look at your whole home as an energy eating beast that needs to be put on a diet. This includes repairing air leaking windows and door seals

It does little good to replace an older HVAC system and expect great reduction in utility bills, if you don?t attend to the areas where you are losing energy. New HVAC systems are expensive and the temptation may be to just install a new high efficiency furnace and air-conditioning system and hope for the best. The fact is, the reduction in utility bills may be disappointing because you may have overlooked a major player in the whole HVAC system?. like the ductwork.

A poorly designed, leaking and under insulated ductwork system can waste 30 percent or more of the money you pay to run your heating and cooling system.and nullify any gain you might realize by installing a new high efficiency system. Many duct systems are poorly insulated and leak conditioned air into un-conditioned attics and crawl spaces. I commonly find disconnected ductwork during my home inspections.

When ducts leak, conditioned air can be forced out unsealed joints and lost. In addition, also un-conditioned air can also be drawn into return ducts through unsealed joints. Attic temperature can be very high in the summer and cold in the winter?so, any attic air that enters your system through un-sealed duct joints will have to be cooled in the summer and heated in the winter, this increases the load on your system and increases your energy bill.

Surprisingly an older home may have a much better designed duct system than a new home and may only need a leak check and insulation upgrade. Newer homes on the other hand may be victim of cost cutting measures and poorly designed duct systems. The use of flex duct has grown in popularity because ease of installation and the high cost of shop made sheet metal ducts. Flex ducts even installed properly are a poor substitute for well designed properly insulated sheet metal ducts. It is common practice to make plenums and coil boxes out of taped together duct board.

Be sure to include an evaluation of your ductwork system in your plans to upgrade your HVAC system. There is no use in exhausting valuable conditioned air to the great outdoors through leaks and worn-out duct insulation. If your duct system needs an overhaul, you might want to consider a high velocity delivery system that uses smaller PVC pipe ducts. These high velocity systems are much easier to install and insulate. The bottom line on a HVAC system upgrade for maximum efficiency must include more than just the new equipment. Don?t forget about the duct work and include it into your budget.

Jim McDonald is a retired contractor and a licensed home inspector

jim@getinfoweb.com