The following are common questions and detailed answers about the ERV fresh air system to help you better understand and use this device.

‌I. Basic usage issues‌

‌Q: Do I have to close the doors and windows when using ERV? ‌

A: Yes! ERV achieves energy recovery through a closed cycle. If the window is open, the outdoor air will flow directly into the room, destroying the energy exchange effect, 

resulting in increased energy consumption and failure to guarantee the filtering effect.

‌Q: Can ERV completely replace window ventilation? ‌

A: It can be replaced. ERV continuously introduces filtered fresh air through mechanical ventilation, while exhausting dirty air. It is more stable than natural ventilation, 

especially in haze, sandstorm weather or low temperatures in winter.

‌Q: Does long-term opening of ERV consume electricity? ‌

A: The power consumption is low. The power of an ordinary household ERV is about 30-80W (similar to an energy-saving lamp), and it only consumes 0.7-2 degrees of electricity 

for 24 hours. The monthly electricity bill is about 20-60 yuan, which is much lower than the energy consumption of air conditioning.

‌II. Performance and effect issues‌

‌Q: Can ERV work normally in extreme weather (such as -10℃ or 40℃)? ‌

A: Pay attention to the following situations:

‌Frosting at low temperature‌: Some models may frost below -5℃, and the automatic defrost function or auxiliary heating module needs to be activated (it is recommended that 

northern users choose the anti-freeze model).

‌High temperature and high humidity‌: When the summer is hot and humid in the south, ERV can block more than 80% of the outdoor humidity, but air conditioning is still needed to 

assist in cooling and dehumidification in extreme weather.

‌Q: When the indoor humidity is uneven (such as the bathroom is humid), can ERV solve it? ‌

A: It cannot be completely solved. ERV is responsible for the overall humidity exchange of the whole house, but local high humidity areas (such as bathrooms) still need to be installed 

separately with exhaust fans for rapid dehumidification.

‌Q: What should I do if the fresh air volume is insufficient and the room is still stuffy? ‌

A: Possible reasons:

‌Too small air volume selection‌: Calculated based on 30m³/h per person or 0.5-1 ventilation times/hour for the room area (floor height 2.8m).

‌Pipeline blockage‌: Check whether the filter is too dirty or the pipeline is dusty, and clean it in time.

‌Installation problem‌: Too many bends in the pipe lead to excessive wind resistance, and the layout needs to be optimized.

‌III. Maintenance and fault problems‌

‌Q: How often should the filter be replaced? Is it costly? ‌

A: The replacement cycle varies depending on the environment:

‌Primary filter‌ (dustproof): clean every 1-3 months, replace every 1-2 years (unit price is about 50-100 yuan).

‌High-efficiency filter‌ (PM2.5): replace every 6-12 months (unit price is about 200-500 yuan).

‌Activated carbon filter‌ (formaldehyde removal): replace every 6 months (unit price is about 300-800 yuan).

Suggestion: shorten the cycle in areas with severe pollution, and regularly check the filter pressure difference alarm prompt.

‌Q: What should I do if the heat exchange core is moldy or has an odor? ‌

A: Processing steps:

Turn off the power and remove the heat exchange core.

Use a vacuum cleaner to clean the surface dust, and brush lightly with a neutral detergent + soft brush (do not soak).

After ventilation and drying, install it back and start the machine for 1 hour to ventilate.

Prevention: Choose an antibacterial coated heat exchange core. Clean it every six months in the humid southern region.

‌Q: The noise of the machine suddenly becomes louder. What may be the reason? ‌

A: Common reasons:

‌Filter blockage‌: The increased wind resistance causes the fan load to increase. Replace the filter in time.

‌Bearing wear‌: The fan needs to be lubricated or replaced after long-term use (contact after-sales).

‌Pipeline loose‌: Check whether there is air leakage at the connection of the air duct and strengthen the seal.

‌IV. Installation and configuration issues‌ ‌Q: Can ERV be installed after decoration? Is a ceiling required? ‌ ‌A: It can be installed, but the following conditions must be met:

‌Cabinet ERV‌: No ceiling is required, and the exterior wall is punched and installed (similar to air conditioners), which is suitable for decorated families.

‌Ceiling ERV‌: Partial ceiling is required to hide the pipeline, suitable for houses with a floor height of ≥2.6m.

‌Q: How large an area can an ERV host cover? ‌

A: Depends on the air volume:

‌Small apartment (≤80㎡): Choose an air volume of 150-250m³/h.

‌Medium and large residential (100-200㎡): 300-500m³/h, or multiple units installed in different areas.

‌Q: How to layout the air supply and return vents? ‌

A: Principle:

‌Air supply vents: Preferentially set in clean areas such as bedrooms and living rooms.

‌Return vents: Close to pollution sources such as kitchens and bathrooms to form an air flow path.

‌Spacing > 1.5 meters: Avoid air flow short circuit (fresh air is discharged without circulation).

‌V. Problems with coordination with other equipment ‌

‌Q: Will ERV and air conditioning conflict when used together? ‌

A: No, they complement each other:

‌Summer‌: ERV pre-cools fresh air to reduce the cooling burden of air conditioning.

‌Winter‌: ERV pre-heats fresh air to reduce heating energy consumption.

Suggestion: The air conditioner temperature setting can be increased (in summer) or decreased (in winter) by 2-3℃, which is more energy-efficient.

‌Q: If you already have an air purifier, do you still need an ERV? ‌

A: The two have different functions:

‌Air purifier‌: Circulates and filters indoor air, but cannot reduce CO₂ concentration.

‌ERV‌: Introduces fresh air and filters it, while exhausting pollutants.

The best solution: ERV+purifier, the former is for ventilation, and the latter is for auxiliary purification.