A gas furnace does not directly remove humidity from the air, but its operation can lead to a reduction in indoor humidity levels due to several factors. The mechanism of humidity reduction, the impact on indoor air quality, and the tools and products to enhance or mitigate humidity removal are discussed in this article.
How Does a Gas Furnace Affect Humidity?
What is the Mechanism of Humidity Reduction?
- Air Draw and Replacement:
- Standard gas furnaces, also known as atmosphere furnaces, draw air from inside the house for combustion. This process creates a deficit of air inside the house, which is then replaced by colder, drier air from outside. This replacement air is typically drier than the indoor air, leading to a decrease in relative humidity.
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High-efficiency furnaces, or sealed combustion furnaces, draw combustion air from outside through a PVC pipe and do not use indoor air. These furnaces do not contribute to the reduction of indoor humidity levels.
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Combustion Process:
- The combustion process itself does not remove moisture from the air. However, the continuous use of air for combustion in standard furnaces can lead to the introduction of drier air from outside, which reduces the overall humidity inside the house.
How Does the Reduced Humidity Affect Indoor Air Quality?
- Dry Air: The reduction in humidity can lead to dry air, which can cause discomfort such as dry skin, cracked lips, and increased susceptibility to illnesses. It also contributes to static electricity and can damage wooden surfaces by drawing moisture out of them.
- Health and Comfort: Low humidity levels can exacerbate cold and flu symptoms, worsen dry skin conditions like eczema, and disrupt sleep due to dryness in the throat and nose.
What are the Technical Specifications and Efficiency Ratings?
- Standard vs. High-Efficiency Furnaces:
- Standard furnaces are more likely to reduce indoor humidity because they draw air from inside the house. High-efficiency furnaces, which draw air from outside, do not have this effect.
- High-efficiency furnaces are generally more energy-efficient and can save up to 40% on heating costs compared to older standard furnaces.
What Tools and Products Can Help Enhance or Mitigate Humidity Removal?
- Humidifiers: To counteract the dry air caused by standard gas furnaces, whole-house humidifiers can be installed. These humidifiers can maintain a comfortable humidity level throughout the house, alleviating the negative effects of dry air.
- Two-Stage Furnaces: While not directly addressing humidity removal, two-stage gas furnaces can provide more consistent temperature and humidity levels by operating at lower capacities for longer periods, which can help in maintaining a more stable indoor environment.
Conclusion
In summary, running a gas furnace, particularly a standard one, can lead to a reduction in indoor humidity levels due to the replacement of indoor air with drier outdoor air. However, this effect is not inherent to the furnace’s combustion process but rather a result of the air draw and replacement mechanism. High-efficiency furnaces mitigate this issue by drawing combustion air from outside. To counteract the dry air caused by standard gas furnaces, whole-house humidifiers can be installed, and two-stage furnaces can provide more consistent temperature and humidity levels.
Reference:
1. Do You Need a Humidifier in Winter Because of the Furnace?
2. Does a Gas Furnace Dry Out the Air in Your Home?
3. Two-stage Gas Furnace: The Unveiling of its Humidity Control Magic.
