- Brand
- Lennox
- Efficiency
- 99% AFUE
- Heating control
- Modulating
- Purchase check
- Full model + written scope
Lennox SLP99V
SLP99V is the useful premium benchmark when the homeowner is paying for fine heat-output control. Compare it with the EL297V before deciding the additional control is worth the installed premium. The decision should identify a real comfort objective, such as reducing temperature swings during long periods of moderate demand, rather than assume a higher AFUE alone will recover every extra dollar. A room that stays cold because of an inadequate branch duct still needs that distribution problem investigated.
Size, efficiency & equipment
| Brand | Lennox |
|---|---|
| Model family | SLP99V |
| Fuel / equipment class | Natural gas; propane conversion only where explicitly approved for the exact model and kit |
| Efficiency | 99% AFUE |
| Burner stages / control | Modulating |
| Blower | Variable-speed |
| Input capacity, BTU/h | Not verified — obtain the exact model specification |
| Rated output, BTU/h | Not verified — obtain the exact model specification |
| Cabinet dimensions | Not verified — obtain the exact model specification |
| Canadian availability | Brand has Canadian-market evidence; exact model, orientation, certification and current local stock require confirmation. |
Manufacturer family headline / up to; confirm selected model.
Family maxima and ranges are not the specification of every size. Obtain the complete model suffix, current output rating and dimensional drawing. Cabinet dimensions do not include all service clearances.
Manufacturer pictures & technical drawings
Manufacturer picture and original source ↗ · Manufacturer-hosted; availability may change.
View manufacturer document on this page
Use the document’s dimensions or technical-data section. On a phone, the original PDF link may be easier to read. This is a manufacturer document, not an installation instruction from this guide.
What makes SLP99V worth comparing
SLP99V is the useful premium benchmark when the homeowner is paying for fine heat-output control. Compare it with the EL297V before deciding the additional control is worth the installed premium. The decision should identify a real comfort objective, such as reducing temperature swings during long periods of moderate demand, rather than assume a higher AFUE alone will recover every extra dollar. A room that stays cold because of an inadequate branch duct still needs that distribution problem investigated.
Capacity and physical fit
A complete model-specific input value is required; this family overview does not substitute a guessed capacity. Obtain the manufacturer-rated output for that same model; this guide does not calculate it by multiplying input by seasonal AFUE. Exact cabinet dimensions were not established in this overview; require the current full-model drawing before accepting fit.
Review the proposed installation
Build the SLP99V quotation around the actual mechanical space. Include a photograph showing the existing furnace, coil, return connection and available access. Ask the installer to mark which components remain and which change. A cabinet dimension is not a service-clearance requirement: the final layout also needs room for filters, drain connections, access panels and safe maintenance. A small advertised furnace can still be an expensive replacement if the surrounding arrangement requires substantial work.
The question that resolves the choice
The specific question to put to the installer is: Which thermostat and accessories are required to obtain the quoted modulation and diagnostic functions? Ask for the answer in writing, linked to the quoted SLP99V model and the work included. If the explanation changes after the visit, retain both versions and identify the newly observed condition. This gives a second reviewer useful evidence and avoids comparing an early allowance with a final assessed price as though they were the same promise.
Read the efficiency number in context
The published 99% figure for SLP99V is a family comparison point. Ask for the selected model’s own rating and keep that record with the proposal. It does not include every household energy expense, determine the price of fuel or establish the condition of the ducts. An operating-cost estimate should disclose its fuel-price and usage assumptions so a reviewer can reproduce the calculation rather than accept an unexplained saving.
Cost, reliability & alternatives
No universal Canadian installed price is asserted. Obtain dated CAD equipment and installed-scope amounts, tax treatment and local assessment; compare like-for-like written proposals.
No defensible comparative Canadian failure-rate ranking established.
Read the Lennox brand assessment · Installed-price context · Compare this model
Sources & verification
Research snapshot: 11 October 2026. Confirm the current complete model, Canadian supply and warranty before purchase.