If your AC is running but not cooling, it is happening due to dirty filters, low gas, blocked coils or evaporator, weak airflow, compressor issues, Circuit fault, thermostat problems, or electrical fault. Professional AC servicing must improve cooling power, reduce electricity bills by about 15% to 30%, and it helps protect the compressor from long-term damage or important parts.
Introduction: Bangladesh is a dusty place in the world. Many AC users ask me during the summer time, why is my AC running but not cooling?” As a professional I can say that it is the most common ask and it is in homes, offices, and shops.
In Many cases I saw that customer mind AC fan runs and both indoor and outdoor units seem active, but the room still does not get cool. Many users think the gas is empty, but the real problem can be different.
It may occur due to high heat, humidity, dust, and long-term cooling service in homes or offices, and then your AC systems stay under heavy pressure. Without proper maintenance and correct installation, with full checking, cooling performance drops quickly.
In this article, I will explain the real reasons behind poor cooling in a simple way, based on real field experience with some troubleshooting methods.
How an AC Cooling System Works
An air conditioning system works by removing heat from indoor air and releasing it outside through the refrigeration cycle.
The major AC components include:
- Compressor.
- Evaporator coil.
- Condenser coil.
- Expansion device.
- Refrigerant.
- Indoor blower fan.
- Outdoor fan motor.
The refrigerant takes heat from inside the room through the indoor coil (evaporator). Then it carries that heat outside and releases it through the outdoor coil (condenser).
A properly functioning Cooling system should provide:
| Parameter | Normal Value |
| Air outlet temperature | 12°C to 18°C |
| Room temperature reduction | 8°C to 14°C |
| Voltage range | 200V to 240V |
| Relative humidity | 45% to 60% |
| Airflow velocity | Manufacturer specified |
If your AC one part system becomes weak, your AC may run continuously without cooling properly.
Main Reasons Why Your AC Is Running but Not Cooling
1. Dirty Air Filters
An AC Dirty filter is one of the biggest reasons behind the poor cooling. When filters become clogged with dust:
- Airflow becomes restricted.
- Heat transfer decreases.
- Cooling capacity drops.
- Compressor load increases.
- Electricity usage rises.
Bangladeshi weather is very rough because dust always flies with the wind due to dusty roads, building construction, and industrial works.
Real Field Experience
A customer in Dhaka, Uttara, Sector-1, (Kamal Ahmed) has complained over the phone to me that his AC was running all day, but the room remained warm. I reached her home, and after inspection, I found the air filter completely blocked with dust. After cleaning the filter and evaporator coil, cooling performance improved significantly within 15 minutes. And he is very happy about my work.
2. Low Refrigerant Gas
Low refrigerant is another major or the most common cause in Bangladesh, Dhaka that why an AC is running but not cooling. Refrigerant does not generally get consumed, like car fuel, but if the gas becomes low, there is May leakage problem.
Common Leakage Areas
- Flare nut joints.
- Copper pipe connections.
- Indoor evaporator coil.
- Outdoor condenser coil.
- Service valve area.
Symptoms of Low Refrigerant
- Weak cooling.
- Ice on evaporator coil.
- Low suction pressure.
- Compressor overheating.
- Long compressor running time.
Refrigeration Principle
The refrigerant absorbs heat through phase change.
Q=m×hfgQ = m \times h_{fg}Q=m×hfg
Where:
- Q = Heat absorbed
- m = Refrigerant mass flow rate
- hfg = Latent heat
If refrigerant quantity decreases, heat absorption capacity also decreases.
3. Dirty Condenser Coil
The outdoor condenser throws the indoor heat outside. If the condenser coil becomes dirty:
- Heat rejection becomes poor.
- Compressor pressure increases.
- Cooling efficiency decreases.
- Power consumption rises.
This problem is very common in Dhaka Bangladesh because outdoor units easily get covered with dust, mud, and pollution particles.
Practical Measurement
| Condenser Condition | Current Draw | Cooling Performance |
| Clean condenser | 6.2A | Good |
| Dirty condenser | 8.7A | Weak |
A dirty condenser coil forces the compressor to work harder, as a result increased electricity bill.
4. Weak Indoor Airflow
If your Air conditioner gas pressure is correct, then weak airflow can reduces cooling power.
Causes of Weak Airflow
- Weak blower motor.
- Faulty capacitor.
- Dirty evaporator coil.
- PCB problems.
- Blocked air vents.
Weak airflow prevents cold air from spreading properly throughout the room, so you feel warm in the room.
5. Compressor Problems
The compressor is the heart of the air conditioner. If your AC compressor efficiency decreases, refrigerant circulation becomes weak, and you feel low cooling in the room.
Common Compressor Issues
- Internal valve damage.
- Overheating.
- Low insulation resistance.
- Locked rotor.
- Winding failure.
Voltage fluctuation is the major cause of compressor damage in Bangladesh, so we offer a voltage stabilizer or a power controller.
Current Analysis
| Compressor Condition | Current | Cooling |
| Healthy compressor | Normal | Strong |
| Weak compressor | High or low abnormal | Poor |
6. Low Voltage Supply
Low voltage is another common problem all over Bangladesh. If you ignore the causes of low voltage, then you feel weak cooling.
When voltage drops:
- Compressor torque decreases.
- Starting difficulty increases.
- Cooling efficiency falls.
- Current increases.
Most split AC systems work best within:
200V≤V≤240V200V \leq V \leq 240V200V≤V≤240V
I strongly recommend using a voltage stabilizer to control electric power.
7. Thermostat or Sensor Problems
Modern inverter AC systems use electronic sensors or a thermostat. If your AC sensors send incorrect signals or an error code, then you see that:
- Compressor speed becomes unstable.
- Room temperature reading becomes inaccurate.
- Cooling becomes irregular.
Common Faulty Components
- Room sensor
- Coil sensor
- Thermistor
- PCB board
8. Frozen Evaporator Coil
Sometimes AC users see ice forming on the indoor coil. It happens because of:
- Low airflow
- Low refrigerant
- Dirty evaporator
- Faulty blower motor
When you see ice form in your indoor coil or evaporator, you feel cooling drops significantly.
9. Incorrect AC Size
Improper AC sizing causes major cooling problems. This is another important problem in Bangladesh. I think many people wrongly do that for saving money, but he does not know this is a future loss, and it’s a major weak cooling issue. When you use an AC smaller than the room load, the system runs continuously without achieving proper cooling.
Cooling Load Formula
Q=UAΔTQ = U A \Delta TQ=UAΔT
Where:
- Q = Heat load
- U = Overall heat transfer coefficient
- A = Surface area
- ΔT = Temperature difference
General Room Sizing Guide
| Room Size | Recommended AC |
| 100 to 120 sq ft | 1 Ton |
| 120 to 150 sq ft | 1.5 Ton |
| 150 to 180 sq ft | 2 Ton |
Energy Consumption Before and After Servicing
A dirt AC consumes much more electricity because the compressor run over the time or the compressor gets stressed.
Real Energy Consumption Data
| AC Condition | Daily Consumption | Monthly Cost |
| Dirty non-serviced AC | 11.8 kWh/day | Higher |
| Properly serviced AC | 8.1 kWh/day | Lower |
Energy Saving Equation
Saving=E1−E2E1×100%\text{Saving} = \frac{E_1 – E_2}{E_1} \times 100\%Saving=E1E1−E2×100%
In many real cases, I saw that regular AC servicing reduces electricity consumption by 15% to 30%.
Why this problem is common in Bangladesh
Bangladesh is in the high difficulties operating conditions for AC use. Because of:
- High humidity
- Dust pollution
- Long operating hours
- High outdoor temperature
- Voltage fluctuation
Above these factors increased the compressor load and reduces cooling power faster in Bangladesh.
ASHRAE Recommendations
ASHRAE recommends:
- Correct refrigerant charging
- Proper vacuuming
- Airflow testing
- Leak inspection
- Coil cleaning
These practices must improve the cooling performance and protect the all internal important parts..
IEA on Cooling Efficiency
The International Energy Agency (IEA) states that efficient cooling systems can extensively reduce electricity require in the worldwide. So, poor AC servicing and maintenance is the waste of energy and money.
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WHO and Indoor Comfort
The World Health Organization (WHO) says that keeping indoor air comfortable and clean is very important, especially in hot and humid countries like Bangladesh and India.
If any air conditioner (AC) does not cool properly in room or cannot control the humidity of the indoor weather, then you feel uncomfortable in the room. It can also affect sleep, work performance, and overall health.
Pros and Cons of Regular AC Servicing
| Pros | Cons |
| Better cooling | Requires service cost |
| Lower electricity bill | Needs regular scheduling |
| Longer compressor life | Poor servicing can create issues |
| Better air quality | |
| Reduced breakdown risk |
Comparison between Serviced and Non-Serviced AC
| Feature | Serviced AC | Non-Serviced AC |
| Cooling efficiency | High | Low |
| Electricity usage | Lower | Higher |
| Compressor stress | Lower | Higher |
| Air quality | Better | Poor |
| System lifespan | Longer | Shorter |
Real Case Study from Field Experience
A customer in Rampuram Banasree, C-Block (Abdul Kalam Miah) reported that his 1.5 Ton AC was running continuously but not cooling the room or weak cooling. I reached her home, and I asked him about the air conditioner, and then he said that:
Initial Problems
- Weak airflow
- High electricity bill
- Hot discharge air
- Indoor humidity remained high
I Inspection Findings:
- Dirty evaporator coil
- Refrigerant leakage from flare nut
- Condenser heavily blocked with dust
My Service Procedure was:
- Leak repair
- Nitrogen pressure testing
- Vacuuming
- Accurate refrigerant charging
- Full coil cleaning
Final Results
| Parameter | Before Service | After Service |
| Room temperature | 33°C | 24°C |
| Compressor current | 8.9A | 6.3A |
| Cooling time | 85 minutes | 30 minutes |
After 3 months, my customer later reported that lower electricity bills and much better cooling comfort.
FAQs.
Why is my AC running but not cooling after gas refill?
It is the most common problem in Bangladesh. It may occur when the gas is wrongly refilled without a leak check, or gas pressure, airflow problems, dirty coils, compressor weakness, or sensor faults. Only an unskilled technician does it.
Can low refrigerant damage the compressor?
Yes. Low refrigerant overheats the compressor and reduces lubrication. As a result, the compressor gets stressed and the pressure increases. After some time, your compressor may be damaged at any time.
How often should AC servicing be done in Bangladesh?
Bangladesh is a dirty place in the world, here are huge dust flying in the wind, and your AC catches this dust in her inside, so you need to servicing every 3 to 6 months.
Does dirty AC increase electricity bills?
Yes. Dirty coils and blocked airflow can increase electricity consumption significantly.
Why does my AC run continuously without cooling?
It has happened cause of low refrigerant, dirty coils, incorrect AC size, electrical fault, circuit problem, or compressor inefficiency.
Final Verdict
If your AC is running but not cooling, it is caused by airflow blockage, low refrigerant gas, dirty coils, compressor issues, voltage fluctuation, or poor maintenance by an unskilled technician. I saw in Bangladesh that many AC users want to select a low-cost technician for the best servicing, but professional servicing costs more. Professional AC servicing is the best way to keep cooling strong, reduce electricity costs, and protect the important parts of your AC.
A well-maintained AC cools faster, uses less power, improves comfort level, and helps prevent major
Hi, this is Khaled from AIRCONcare. I have been working in multi-brand Air Conditioner Sales and Service for about 18 years. I have many top-most efficient technicians and engineers.