If you’re researching Lennox high-efficiency furnaces, two models likely stand out:
- Lennox EL296V
- Lennox SLP99V
Both are highly efficient. Both are reliable. But they serve different types of homeowners and comfort expectations.
At Marsh Heating & Air Conditioning, we’ve installed Lennox systems throughout the northwest metro since 1974. Here’s how these two models compare — and how to determine which is right for your home.
Efficiency Comparison
🔹 Lennox EL296V
- Up to 96% AFUE
- Two-stage heating
- High efficiency for most homes
🔹 Lennox SLP99V
- Up to 99% AFUE
- Variable-capacity heating
- Premium-tier efficiency
What Does That 3% Difference Mean?
In Minnesota’s long heating season, the 99% AFUE SLP99V converts slightly more gas into usable heat.
For larger homes or long-term homeowners, that difference may create noticeable long-term savings.
For smaller homes, the EL296V may already provide excellent efficiency.
Comfort Performance
EL296V (Two-Stage)
- Operates at low or high output
- Improved comfort over single-stage systems
- Reduced temperature swings
- Good balance of cost and performance
SLP99V (Variable-Capacity)
- Adjusts heat output in small increments
- Maintains highly consistent temperature
- Superior comfort control
- Better humidity balance in winter
If comfort consistency is a top priority, the SLP99V leads.
Noise Levels
Both systems are quiet compared to older furnaces.
However:
- The SLP99V’s variable operation often results in smoother, quieter airflow.
- The EL296V remains very quiet but operates in two defined stages.
In most homes, either option will be noticeably quieter than older equipment.
Ideal Applications
Lennox EL296V Is Ideal For:
- Budget-conscious homeowners
- Smaller or mid-sized homes
- Homeowners wanting strong efficiency without premium pricing
- Replacement of older 80% furnaces
Lennox SLP99V Is Ideal For:
- Larger homes
- Two-story homes
- Homes with comfort imbalance issues
- Long-term homeowners
- Energy-focused buyers
- Zoning system integration
System Pairing Considerations
Both furnaces pair well with:
- Lennox variable-speed air conditioners
- Lennox communicating thermostats
- Zoned duct systems
However, the SLP99V integrates more fully with advanced communicating controls for maximum performance.
Proper pairing matters more than model choice alone.
Installation Matters More Than the Model
Even the best furnace performs poorly if:
- It is improperly sized
- Airflow is not balanced
- Ductwork is restricted
- Gas pressure is incorrectly set
Since 1974, Marsh Heating has emphasized:
- Manual J load calculations
- Airflow design
- Combustion testing
- Proper commissioning
The right installation ensures the furnace performs to manufacturer specifications.
Cost vs Long-Term Value
The EL296V has a lower upfront investment.
The SLP99V has a higher upfront cost but may offer:
- Increased comfort
- Greater energy savings
- Longer-term value
- Premium system integration
Choosing between them depends on:
- Budget
- Home size
- Length of ownership
- Comfort expectations
Frequently Asked Questions
Is 96% AFUE enough in Minnesota?
Yes. 96% is highly efficient and suitable for most homes.
Does 99% AFUE justify the upgrade?
For larger homes and long-term ownership, often yes.
Is the SLP99V more reliable?
Both are reliable when installed properly. Installation quality matters most.
Which furnace lasts longer?
With proper maintenance, both can provide 15–20+ years of service.
Lennox Furnace Installation Since 1974
Choosing between the EL296V and SLP99V requires more than comparing numbers.
Marsh Heating & Air Conditioning has installed Lennox furnace systems throughout the northwest metro since 1974, helping homeowners select equipment that matches their comfort goals and home design.
If you’re deciding between these two Lennox furnaces, call 763.536.0667 for a professional consultation.
Proper sizing and airflow design determine long-term performance.