(19)Fresh off Patent
(45) Week of Oct 5, 2026 No. 5 3,852 lapsed 197 picks
Energy & batteries · expired at full term Oct 7, 2026

Solar air heater with channeled partitions creating isolated flow sections

A roof- or wall-mounted solar air heater that divides its cavity into multiple largely isolated sections using parallel partitions that contain many parallel channels. Air is forced through the heater by fans and passes sequentially through the sections via the channels in the partitions; a temperature controller cycles the fans. Intended users are homeowners or installers adding supplemental space heating or preheating ventilation air.

Sheet 1 of the patent drawingsSheet 2 of the patent drawingsSheet 3 of the patent drawings

(57) What the patent covered

The principal independent claim covered a housing with a light-transmitting front, two or more essentially parallel partitions that create essentially isolated sections, each partition including a plurality of parallel channels that allow fluid communication between adjacent sections along a route perpendicular to both the partition’s normal and longitudinal axes, one or more air inlets/outlets, fans to move air through the housing, and a temperature controller to switch the fans at set temperatures.

The distinctive part: The partitions themselves contain parallel channels that pass air between otherwise isolated chambers, producing step-wise heating and reducing mixing of cold inlet air with already-heated air.

Novelty 3/5. At filing time the basic solar box/greenhouse heater and multiple-slat absorbers were common; the invention’s novelty was using multi-chamber flow with channeled partition walls to stage heating and limit mixing rather than simply increasing surface area.

Making it

stamped or folded sheet-metal housing and divider panels (or injection-molded/chambered polymer partitions), cut/transparant glazing installed by sealant or gasket, off-the-shelf fans fitted and wired to a basic thermostat controller; final assembly likely manual or semi-automated.

Materials: sheet metal or extruded aluminum housing, polycarbonate or tempered glass light-transmitting panel, thin-formed metal or plastic partitions with molded/pressed channels, axial or blower fans (steel/plastic impellers)

Manufacturability 4/5. Requires several stamped/folded panels and channeled partitions but uses common fabrication (sheet metal work, molding) and off-the-shelf fans and controllers; moderate part count and hand assembly for seals and controls.

Is anyone buying?

We haven't run a demand check on this one yet. Shoppers would likely search for solar air heater multi-chamber, solar forced-air wall heater, solar ventilation preheater; the links on the right open those searches.

Who buys it: homeowners and installers wanting supplemental or preheated ventilation air

Before you make it

We didn't find any related continuation or divisional patents still in force, although that doesn't rule out design patents, trademarks or unrelated patents covering the same product.

Practical considerations include weatherproofing and glazing standards, fan and controller electrical safety/clearances, and a crowded, low-margin market for DIY and commercial solar air heaters; the patent has lapsed so no active protection remains.

This patent reached the end of its full term, so it can't be revived, but this page is still a research lead rather than legal advice, so get a freedom-to-operate opinion before you manufacture anything.

Claim 1, as granted

1. A solar air heater providing heating of air in a step-wise manner, comprising: a housing, said housing comprising a front panel of light-transmitting material, one or more air inlets and one or more air outlets for establishing a flow path for the air to be heated, two or more partitions, said partitions being essentially parallel to each other creating essentially isolated sections within said housing between said partitions, wherein each partition has a longitudinal axis and a normal axis, said normal axis being perpendicular to a face of said partition, wherein each partition comprises a plurality of parallel channels permitting adjacent essentially isolated sections to be in fluid communication and wherein said fluid communication is through said partitions, such that said fluid communication between said adjacent essentially isolated sections and through said partitions is along a route perpendicular to the normal axis of each of said partitions and perpendicular to the longitudinal axis of each of said partitions; and b. one or more fans for moving air through said housing by way of said air inlets and said air outlets, and c. a temperature controller for turning said fans on and off at preset temperatures.