What makes ac cold

The basic concept is much easier to understand when the components are broken down , as follows: The compressor runs off an engine belt that squeezes or compresses the gaseous refrigerant. Once it has been pressurized, the condenser cools it down through a series of finned tubes where it returns to a liquid state. This liquid will then pass through a dryer or receiver that removes excess water to eliminate the risk of ice crystal formations inside the AC system.

Next the liquid refrigerant enters the evaporator via a thermal expansion valve where it is then exposed to heat from the vehicle's cabin. At this point the fluid boils, reducing it to a gas form once again. During this process the heat from the surrounding air is absorbed causing the evaporator coil to chill. Finally, it is redistributed throughout the cabin by the blowing fan through the vents as cool, crisp air-conditioned air.

Here are the top 3 reasons why your car AC may not be blowing cold air : 1 Your Car's AC Needs a Recharge The most common cause of a vehicle's air conditioner not getting cold enough is that it needs to be recharged. AC cycles on and off frequently. Hissing sounds from the AC system when the engine is off. Oil residue around AC pipe fittings and hoses. We're Auto Mechanics! Without the air conditioner working properly, the inside temperature soars.

Left that way too long, clogged filters can also cause parts to wear out faster than they should. It can even affect the evaporator coil and condenser and create a much larger problem. In addition to routine cleaning, the filters should be changed every three months. If you have indoor pets, you may need to change it more often. You should be able to replace indoor air filters easily yourself. However, if you are unsure of the correct filter to use, an AC technician can help.

The filters mentioned above do their best to keep the coils clean and operating at peak performance, however, even the coils will wear out over time. Because of the constant moisture, your indoor evaporator coil can be prone to problems with mildew and even mold.

UV lights can guard against this and keep your air cleaner. Coils can also freeze up if the refrigerant is running low within the system.

Issues with the coils will cause major disruption within the air conditioning unit and should be seen by an HVAC professional as soon as possible.

The condenser can also wear out over time. When your air conditioner is not blowing cold air and no other reason is found, have this checked as well. Just like air filters that are clogged and restrict airflow, a blocked or clogged register or vent can do the same thing. A return air register takes air into the system, and supply vents blow conditioned air into the house. Clogs in either cause problems.

The ventilation system runs throughout the house and if something creates a blockage or a leak in the ductwork, it will affect the cooling. A tear or hole in the ductwork could mean your cold air may be leaking out of your attic. Rodents like mice or rats that take up residence in your attic can do a number on ductwork and create leaks that affect how your system cools.

When something is restricting air near the vent itself, only the room with that vent may feel warmer than the rest of the house. Refrigerant expands in the indoor coils, causing it to get very cold. Heat transfer then takes place between the refrigerant and the circulating air. As the refrigerant absorbs heat from the air, the air temperature gets colder.

Dirt and grime on your coils can keep this heat exchange from occurring effectively. Fortunately, cleaning your coils in this situation can make your air conditioner colder.

Low refrigerant levels can also play a part in limiting proper heat exchange and inhibiting effective cooling. Restrictions or leaks in refrigerant lines can also contribute to poor cooling. Additionally, there may be combined factors causing poor system performance, making it important to have your equipment checked thoroughly. One of the most affordable ways to deal with low air pressure and poor temperature control is to schedule preventative maintenance.

A thorough inspection is provided to evaluate system performance. Basic adjustments are made to ensure that your equipment operates at its best possible levels. For example, at 95F, my system has a high side pressure of lbs. Steve, installing AC on north Steve, installing AC on north or northeast side of house or otherwise providing shade will increase both capacity and efficiency.

Keeping sun off the condenser is a great strategy in new construction when the cost may be next to nothing often depends on location of air handler, as well as aesthetic and noise considerations. If you plant vegetation or build a shading structure, just be sure to respect the mfr recommended clearances.

For heat pumps, ideal placement would put the unit in direct sun in the AM and shaded after noon. Outstanding, you could not Outstanding, you could not have made it clearer, with the exception of the gravitational analog How do you find the time……. Kevin L. David Butler did a great job explaining why the temperatures are different in a comment below yours. Steve : I was focusing only on the thermodynamics of air conditioning in this article.

Naturally, a better building envelope and ducts inside make the home more efficient and the equipment more durable, as will right-sizing.

Improving the conditions of the condensing unit also help. Mark T. I wanted to avoid as much of the technical terminology as I could to keep this post simpler, though. Stefan : Thanks! I hope the other person finds it as understandable. David K. Thanks for mentioning it. David B. Carl C. Mike : Mike : Thanks for the info about Gorrie. He used the ammonia cycle to cool air about 30 years before Gorrie was making ice in Florida.

Donald B. The refrigerant coming out of the expansion valve does evaporate to a small degree. Mostly, though, it becomes a mist of liquid droplets at that point, with the bulk of the evaporation happening inside the evaporator coil. Did you read part 2 of this series? Otherwise, the evaporator would absorb very little heat from the home.

Bill S. Very great resource Thanks! Very great resource for those who want to know how the air conditioner or refrigeration works. I linked to this from your article about sweat , another good one.

As a culture we are more willing to pay for what we want than what we need. Thanks for the explanation, Thanks for the explanation, it was very clear. The analogy is a good way to remember and trigger the whole idea. The explanation is really The explanation is really very nice. Thank you for helping me…! I might be an outlier but it actually made all the other stuff much clearer. Michael : Michael : Thanks! In our country we decipher In our country we decipher the HVAC principle…the outdoor unit now is blowing cold air at same time in the indoor.