If you’re shopping for a new furnace, take the time to explore the new and redesigned components that place high-efficiency furnaces in a class by themselves. With safer operation, greater fuel efficiency and many comfort features, you may be scratching your head finding it difficult to decide which upgraded feature you like the best. 
Safety, efficiency and comfort
“High-efficiency furnaces” are furnaces that reach or exceed 90 percent AFUE (annual fuel utilization efficiency), which is a 12- to 30-percent improvement over mid-efficiency and older furnaces. The improvements and features that new furnaces deliver go well beyond increased fuel efficiency.
Each redesigned component enhances the performance of the next, to deliver safer operation and optimal comfort for homeowners. These are the improved components and features of high-efficiency furnaces:
- A sealed combustion chamber with direct-vent intake delivers greater fuel-to-heat conversion. Also, warm household air is not wasted for combustion purposes. Sealed combustion prevents airborne household contaminants and chemicals from corroding components. Direct-vent intake is one of the features that prevent high-efficiency furnaces from back-drafting.
- A modulating gas valve enhances home comfort by automatically adjusting heat output to match the changing heating needs of a home. Heat output can be increased or reduced in one-percent increments, which significantly reduces fuel consumption.
- A variable-capacity blower provides smooth and even heating through the entire home by adapting airflow to the temperature needs in your home. Variable-capacity blowers drastically reduce electricity consumption.
- The secondary heat exchanger condenses hot exhaust gases received from the primary heat exchanger before the exhaust gases are vented out the flue (as with conventional furnaces). The secondary heat exchanger extracts nearly all latent heat, and converts it into usable heat for your home. The exhaust gases are cooled to such an extent that sealed sidewall venting is feasible, the most practical and safest option.
- Sidewall venting, sealed combustion and direct-vent intake all help eliminate back-drafting.
For more information about high-efficiency furnaces, please contact us at Marsh Heating & Air Conditioning today, and we’ll help you decide which components and features are best for your home. We’ve proudly served homeowners in the Twin Cities area for over 38 years.
Our goal is to help educate our customers in Minneapolis-St. Paul, Minnesota about energy and home comfort issues (specific to HVAC systems). For more information about high-efficiency furnaces and other HVAC topics, download our free Home Comfort Resource guide.
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