How much does a car’s AC affect fuel efficiency and performance?
How Much Does the AC Affect Fuel MileageYour car’s air conditioner is an important accessory – it helps keep you and your passengers comfortable and safe during hot weather. However, it’s operated by your engine and places an additional load on your engine when it’s running. That means it increases your fuel cost (decreases your fuel economy). How much does it affect your fuel mileage? The answer is: a lot.How much will my fuel mileage be affected?Note that there is no single answer to this question, as there are a number of different factors in play. The actual temperature outside will have an effect, as will the size of your engine, the make and model of your car, the condition of your air conditioning system and many others. Running the air conditioner in very hot weather can increase your fuel consumption by up to 25%, and that the effect of using the AC in a hybrid or electric vehicle can be even greater.The best defense against decreasing fuel economy is actually pretty simple –Use your windows at lower speeds, and turn on the air when you hit the highway. Of course, open windows increase drag, which also reduces fuel economybut the impact isn’t as high as running the AC at lower speeds in the city conditions.
2006 Subaru Outback - AC performance problem - Hot Air Comes in periodically when running AC in Max-Cold Recl?
Air Conditioner is Not Cooling Properly - Specifics: Driving Conditions: ALL (local 35-45 mph avg. and Hwy 65-70 mph normal speeds – Note: Issue does NOT just occur under severe engine load conditions it occurs under all conditions) Settings: A/C: – ON Recirc: - ON Fan Speed: All (1-4) Symptoms are more obvious at 2, 3 & 4 Vent Settings: Dash & Dash/Floor Symptoms: A/C blows very cold air for 10-20 seconds alternating with Very Warm to Hot air for 5-10 seconds - Warm Air temp is much hotter than ambient in-car air indicating that Outside Air is being blown thru the system. There does not appear to be a change in the engine RPM’s or Audible evidence that the compressor clutch is disengaging. Also when in the Dash/Floor setting there is low flow to the passenger floorboard. Cause???– air-flow obstruction or errant signal that is causing a damper/actuator to periodically open a valve - Dealer replaced clogged cabin air-filter - problem still occuring! Similar prob?
Does heat index affect air conditioner performance?
Yes, it is about the humidity and yes the more humidity the harder your a/c has to work until it lowers the humidity in the house. Besides the water in the air (in the house) being more mass that requires cooling, when the moisture is condensed it releases heat. Trying to cool more humid air can lower the efficiency of the a/c as much as 15%. The good news is that the a/c will lower the humidity in the house when working so then it only needs to remove the moisture that may come in to the house. Where you would likely notice it the most is if you turned it off during the day. Then when you turned it on, the more humid the air is in the house the longer it would take until the air started to cool down because it will be working to remove that moisture first. If it is on all the time, you likely won't notice it, and it will only affect the a/c a little because you are not trying to cool the humid outside air unless the house is real drafty. Good Luck.
Does the air filter in your car affect the performance of the air conditioner?
Depends on which filter you're talking about. Some cars have "cabin filters" which purifies the air for your a/c & heat system. If this is clogged/dirty then yeah sure it can affect the air conditioner because you would have less airflow going through it. The engine air filter will have nothing to do with performace of your air conditioner.
Does running the AC in your car use additional fuel?
Yes it does. (That’s your short answer, I love cars and engineering so the following is a nice long answer)A vehicles air conditioning system removes heat from air through a phase change. The entire system is sealed under vacuum, and in these conditions, the liquid coolant in the AC system will boil at a very low temperature. When the liquid boils it expands rapidly and pulls heat from the system.Experiment: place your hand in front of your mouth, open your mouth really wide and breath a heavy lung full of air into your hand. Notice how hot the air feels? Now make a very tight “o” with your lips and blow onto your hand, almost like you’re whistling. Try to breathe out at rate where the gust of air coming from your mouth is moving about the same speed as it was in the first part of the experiment so you can rule out velocity. Notice this is cool? The air is coming from your lungs both times so why does it behave in this way? The science is that when you leave your mouth open and puff the air out, it travels as one big mass carrying the heat of your body. When you make a small opening, the air comes out into the atmosphere and starts to spread out dissipating heat.Now back to your car. The AC uses an evaporator, a condenser, and a compressor. The evaporator is inside the cabin of the car, and it is where the liquid refrigerant becomes a gas before a fan inside your car blows the hot air through and removes heat making you feel cold air. The gas moves back through the system where it is brought back to a liquid phase in the condenser. In order to condense more easily, the gas is compressed by the compressor. Compressing this gas requires quite a bit of energy and this energy comes from a belt running off of an accessory pulley on your engine. When you turn in the AC, a compressor clutch engages the compressor to he engine and put an extra load on the engine. The engine must burn more gas to overcome this load and it is being less efficient. It also takes in slightly more load from the alternator to pull the current to run the blower fan motor in the dash board that the AC uses, but this loss is negligible in comparison to what the compressor needs.
Does a car consume more fuel with the fan on?
Modern automobiles have two or more fans:* Radiator Fan* Interior heat and cooling fan(s)The fan that pushes air over the radiator (water) oil (oil) and AC coils (refrigerant) can be driven either by the vehicles electric system or via belts (a.k.a. fan belts). Sometimes we see both electric and belt driven, but that’s really rare.Electric and belt-driven radiator fans do consume energy, thus fuel, but at levels that are so low, even good scientific equipment will not always show the impact.Ditto for the electric fans that move heated or cooled air around inside the vehicle.So no. Do not avoid using interior fans - especially defrost - nor disconnect belt-driven engine fans for economy purposes. Your gains will be very hard to measure and if you can measure something, the gains will be counted in fractions of pennies.The main reason someone would ask this question is if they wanted to squeeze out a fraction of a horsepower for some sort of amateur racing. Pro’s already know this answer to three or four decimal places.Good question, my answer is: Don’t bother.
Car Air Conditioning and Refrigerant Question?
1) AC Systems are sealed, service (system being evacuated) is only necessary when a component is being replaced (Orifice tube, TXV thermal expansion valve, compressor, condensor, accumulator etc) If the system is low it is topped off. 2) Yes topping off a system is easy, however if you are a novice you might want to leave this to a professional. Yes Walmart sells a low side (vacuum) gauge and a charging hose, however the high side is also critical to knowing overall system performance. In essence a Manifold at the minimum is required to properly service any AC system, a charging station is optimum. 3) Yes you need R-134, the question is how much do you need AC systems typically hold between 2 and 3 pounds. If you only have one car to charge then cans are fine, the cans are generally 12 ounces and run $6 at wal-mart. I have never seen a 37 lb canister, just 30 lbs the can and outer box weighs about 6lbs There are also 50LB canisters and 20 LB canisters but they are rare. 4) You need at least a low pressure (vacuum) side gauge. The way your question reads does not instill me with confidence in your abilities... but... you should also examine all hoses, fittings and the manifold on the back of the compressor for signs of oil, this would indicate a leak. EPA states that under their service guidelines that a 1lb leak over a 12 month period is permissible, seems excessive to me but hey I don't write policy for them. If you have a minor leak recharging the system is what I would reccomend.
Does car air conditioner have anything to do with engine oil change?
I have 2004 Toyota Highlander v6 model. My wife usually drives this car and about 3 weeks ago, she told me the hot air would come out for a bit once in a while when she turns on the A/C. And sometimes the hot air comes out for very long. She knows her car well enough to know how to turn on A/C and set it so that cold air comes out, so it's not a user error. However, when I tried a few times, I didn't notice the problem. I did notice the warm air once when I tested but it was only for very short time. She also told me that she notices the problem more often when the car had been out in the sun for long that the car is hot. My engine oil changing date was bit passed (I change every 3000 miles, but it's gotten to 3500), so I changed it. Since then my wife hadn't noticed the warm air problem with A/C. And she's been using the car almost everyday for past 2 weeks now and during that time we even drove for about 2 hours straight and didn't notice the problem. So I actually have 2 questions. 1. Does the car's A/C have anything to do with engine oil change? 2. My guess something is starting to go bad with my A/C unit. Is it something that I can wait until the problem shows definitely or would it be better to take it to mechanic now when problem is mild and fix whatever is the issue (i.e. would it damage more and cost me more if I wait and fix it later?)