Finvest
LII HVAC & Building Products · HVAC · Residential · Commercial · Thesis updated July 19, 2026

Commercial strength masks a weak home market

01 Running thesis

Commercial is carrying the load

Lennox looks like two different businesses right now. The commercial side is strong. In Q1 2026, Building Climate Solutions grew sales 38% and segment profit 63%, helped by higher volumes, acquisitions, and better price and mix.

The home side is the problem. Home Comfort Solutions sales fell 10% in Q1 2026, and underlying volumes were down 21%. That is still a deep drop, but management said it improved from a 32% volume decline in Q4 2025. The bull case starts with that change: residential demand may be finding a floor.

The biggest near-term test is pricing. Management now expects cost inflation of about 5%, up from 2%, because of tariffs and input costs for aluminum, steel, copper, and fuel. Lennox announced price increases to protect margins. If those increases stick and residential volumes keep getting less bad, earnings can recover in the second half.

The bear case is simple: the home market may stay weak, and price increases may make demand worse. If customers push back on higher prices, Lennox could face both lower volumes and higher costs. That is why the stock deserves a balanced view rather than a clean growth story.

Apr 2026Q1 2026 sharpened the split in the business. Commercial results were very strong, while residential volumes were still down 21%, but management said that was better than the 32% drop in Q4 2025.
Apr 2026The earnings call added a new cost concern. Section 232 tariffs and input costs pushed expected inflation to about 5%, so the next test is whether new price increases stick.
Feb 2026The 2025 10-K confirmed a deep residential slowdown, with Home Comfort Solutions full-year volumes down 17%. It also showed commercial profit growth and added context on new acquisitions and joint ventures.
Oct 2025Q3 2025 flipped the story toward commercial strength and residential weakness. Home Comfort Solutions sales fell 12% on a 23% volume drop, while Building Climate Solutions sales rose 10%.
Jul 2025Q2 2025 showed that price and mix were doing most of the work while volumes fell in both segments. The bear case became more focused on volume declines and product cost inflation.
Feb 2025The 2024 10-K showed strong revenue growth and margin expansion, but it also flagged demand pulled forward by refrigerant regulation changes and factory inefficiencies in Mexico.
Oct 2024Q3 2024 showed broad strength, with both key segments growing sales 15%. The update also put a clearer number around factory ramp costs that pressured margins.
Jul 2024The first thesis set Lennox up as a two-segment HVACR company with strong Building Climate Solutions momentum. Main risks were weather, housing cycles, and raw material costs.
02 Business model

Selling comfort through cycles

Lennox makes HVACR products, which means heating, ventilation, air conditioning, and refrigeration equipment. It sells through direct sales, distributors, and company-owned stores.

A large part of demand comes from replacing old systems. The rest is tied to new construction. That mix helps because broken equipment must often be replaced, but it does not remove cycle risk. Higher rates, weak housing, and lower consumer confidence can still hurt sales.

Weather matters. Hot summers and cold winters can pull demand forward, while mild weather can delay purchases. Raw materials also matter. Steel, aluminum, copper, and fuel are major costs, so Lennox relies on pricing actions and hedging to defend margins.

The company is also adding products around the core HVAC system. In October 2025, it bought Duro Dyne and Supco, which sell HVAC parts and supplies. It also has joint ventures with Ariston Group for water heaters and Samsung for ductless AC and heat pump products.

03 Product portfolio

What Lennox sells

Cash cow

Residential heating and cooling systems

This is the core Home Comfort Solutions business. It sells home air conditioners, heating systems, and related equipment for replacement and new construction.

Growth engine

Commercial heating and cooling equipment

This is the Building Climate Solutions business. It is the current earnings driver after Q1 2026 sales rose 38% and profit rose 63%.

Steady

Refrigeration products

Lennox sells refrigeration equipment and related services for commercial uses. This gives the company exposure beyond home HVAC cycles.

Option

HVAC parts and supplies

Duro Dyne and Supco added parts and supplies for residential and commercial customers. These bolt-on deals broaden the product shelf.

Option

Ductless AC and heat pump products

The Samsung joint venture expands Lennox into ductless air conditioning and heat pump products. This could help it serve homes and buildings where ducted systems are less practical.

Option

Water heaters

The Ariston Group joint venture gives Lennox a path into water heaters. It is an adjacent product area rather than the main profit engine today.

04 Business segments

Two segments, opposite trends

Home Comfort Solutions57%declining
Building Climate Solutions43%growing fast

Segment mix uses Q1 2026 net sales: $650.0 million for Home Comfort Solutions and $485.1 million for Building Climate Solutions. The residential segment is still larger, but commercial produced more segment profit in the quarter.

05 Risk factors

What could break the thesis

Residential volume slump

High impact · High odds

Home Comfort Solutions underlying volumes fell 21% in Q1 2026. That was better than the 32% decline in Q4 2025, but it still shows weak housing and a cautious consumer. If the summer season does not improve, the stabilization case weakens.

We watchQuarterly Home Comfort Solutions underlying volume change.

Tariff and commodity squeeze

High impact · Medium odds

Management raised expected cost inflation to about 5% from 2% after new Section 232 tariffs and higher input costs. Lennox is using price increases to offset that pressure. If price increases fail, margins could compress.

We watchManagement updates on cost inflation, tariffs, and price realization.

Price increases hurt demand

Medium impact · Medium odds

Higher prices can protect profit per unit, but they can also push buyers to wait or choose cheaper options. This is most important in residential HVAC, where demand is already weak. Lennox needs price to stick without causing another leg down in volume.

We watchHome Comfort Solutions price and mix versus unit volume in the next two quarters.

Commercial growth cools off

High impact · Medium odds

Building Climate Solutions offset the residential downturn in Q1 2026. Sales rose 38%, including 17% underlying volume growth. If that strength fades, Lennox loses the main support for the bull case.

We watchBuilding Climate Solutions organic volume growth and segment profit growth.

Factory under-absorption lasts longer

Medium impact · Medium odds

Home Comfort Solutions segment profit was hurt by about $15 million of manufacturing under-absorption in Q1 2026 as Lennox managed inventory. Under-absorption means factories make fewer units than planned, so fixed costs are spread over fewer products. If production stays low, this drag can last.

We watchManagement comments on inventory normalization and factory utilization.

AI catch-up risk

Low impact · Medium odds

The 2025 10-K says artificial intelligence can create opportunity and risk. Competitors could use AI to serve customers better, improve internal efficiency, or build better products. This is not the core issue today, but it can affect long-term competitiveness.

We watchNew digital tools, service automation, and product features from Lennox and peers.
06 Quick answers

In one breath

What does Lennox International do?

Lennox makes heating, cooling, ventilation, and refrigeration equipment. It serves both homes and commercial buildings through direct sales, distributors, and company-owned stores.

Why are Lennox residential sales weak?

Home Comfort Solutions is tied to the housing cycle, consumer spending, and replacement demand. In Q1 2026, underlying residential volumes fell 21%, which shows buyers are still cautious.

What is the main bull case for Lennox?

The bull case is that commercial strength stays high while residential demand stabilizes. If price increases offset 5% cost inflation, margins could improve as factory under-absorption fades.

What should investors watch next?

Watch whether price increases stick and whether Home Comfort Solutions volumes keep improving from the Q4 2025 low. Also watch if Building Climate Solutions can keep double-digit organic volume growth.