AC Infinity IONBOARD S44 Review: 2022 Heat Test Revisited

Last updated: November 2, 2026

Quick answer: The AC Infinity IONBOARD S44 I grew with in 2022 was a powerful, well-built panel with strong vegetative performance, but the heat became difficult to manage when I pushed it past 40% in my already-warm 5×5 garage tent. That was my grow, and a cooler room may treat it better.

Old-model warning: This video documents the exact S44 I received in 2022. It calls that unit a 1,024-diode Samsung LM301B fixture. AC Infinity’s current S44 page uses the same AC-IBS44 model code but advertises 1,024 Samsung LM301H diodes, 430 watts and 2.75 µmol/J. That could be a hardware revision, a listing change or my mistake in the video. Verify the label and specifications on the actual light you are buying. The State of the Indoor Grow Equipment guide explains why newer same-name equipment can perform worse than the version that earned an old recommendation.

AC Infinity savings: If you buy from AC Infinity directly, use code EVYGROWS at checkout for additional savings on eligible products.

Video chapters

1. 0:19 — Why I test lights with real grows
2. 0:38 — Build and panel design
3. 0:51 — 2022 diode and PPFD discussion
4. 1:18 — The 20% dimmer steps
5. 1:39 — Vegetative growth result
6. 2:26 — Reservoir and tent heat at higher power
7. 2:49 — My 2022 verdict

Selecting a timestamp opens the player at that moment without moving you away from this section.

What I liked about the 2022 S44

The panel felt sturdy, the hanging hardware was solid and the rubber bumpers protected the diode side when the light was placed on a rough surface. The canopy response in vegetative growth was the strongest part of the test. At lower power, the plants filled the space quickly and the panel produced the kind of even-looking growth I wanted from a 4×4-class light.

The main control limitation was simple: the onboard dimmer moved in 20% steps. If 40% was too weak and 60% was too strong, the practical adjustment was not a tiny turn of the dial. I had to raise the fixture, lower it or use a compatible controller. That is still worth remembering because AC Infinity’s current page continues to describe 20% manual increments.

What happened when I increased the power

The problems showed up after I moved the plants into a larger 5×5 tent in a warm garage. I had stayed at or below 40% during vegetative growth. At 60%, the room became much harder to control. At 80%, I recorded a roughly 20°F difference between the garage and tent even with the inline fan running at its highest setting.

That environment also contained a hydroponic reservoir. The water temperature climbed, and the grow developed root rot even though I had a chiller. I think the hot root zone contributed, though dissolved oxygen, pathogens, plumbing, water movement and sanitation can all affect root health.

Does the IONBOARD S44 overheat?

Every 430-watt fixture eventually adds roughly its electrical load to the room as heat. A panel can change where that heat is concentrated and how easily air carries it away, but it cannot make the energy disappear. My test shows that this S44 was a poor match for my warm garage, high-power setting and hydro reservoir.

If your intake air is already warm, solve the room before buying more light. Measure temperature at canopy height, compare the room with the closed tent and watch the root-zone temperature separately in hydro. An inline fan can only exhaust toward the conditions available outside the tent. The temperature and humidity guide explains the complete climate workflow.

2022 review unit versus today’s listing

Those current values are manufacturer claims. I have not opened or tested a current retail S44, so I cannot confirm whether the internal board, driver, spectrum, thermal behavior or output matches the 2022 unit. A familiar name is not enough. Ask for the current manual and model label, inspect the received hardware, and map the exact light at canopy height.

My practical verdict

The old S44 was excellent for vegetative growth and usable when the room could absorb the heat. I would not repeat the same high-power hydro setup in a hot garage without better room cooling, a thermometer and hygrometer and independent root-zone monitoring. In a cool room or winter grow, the same heat may be manageable. In a warm room, a more open bar-style layout or a lower-wattage fixture may be easier to live with—but it still has to be measured.

Before choosing any light, use the LED grow-light buying guide. After it arrives, follow the LED measurement tutorial and build a center-edge-corner PPFD map with a quantum meter instead of copying my hanging height.

Recommended measurement and setup tools

Full-spectrum quantum meterMap the exact light you receive instead of assuming an old model’s output or hanging height.View product

Thermometer and hygrometerCompare intake-room and canopy conditions with an independent sensor before blaming one piece of equipment.View product

Rated rope ratchet hangersLevel the panel and make height adjustments between the S44’s broad manual dimmer steps.View product

Affiliate disclosure: HWGrow may earn a commission from qualifying purchases at no additional cost to you. Equivalent tools can be substituted without changing the measurement method.

Need help checking a current S44?

Ask HWGrow and include the listing, model label, diode claim, wattage, tent size, room temperature and PPFD grid. The Grow With Me Masterclass demonstrates how light, airflow and environment work together without reproducing protected lessons here.

AC Infinity IONBOARD S44 FAQ

Is the current S44 identical to the 2022 review light?

I cannot say. In the video I call the 2022 light an LM301B fixture, while AC Infinity’s current page advertises LM301H diodes under the same AC-IBS44 model code. Verify the exact received hardware.

Did the S44 cause a 20-degree temperature increase?

I saw that difference in my warm-garage, 5×5-tent hydro setup at the higher power setting.

Why were the 20% dimmer steps a problem?

When one step was too weak and the next was too strong, the fixture height had to change to reach a more useful canopy intensity. A compatible controller may offer another control path.

Would you use the old S44 again?

Yes for vegetative growth or in a cool room where its heat can be managed. HWGrow would not repeat the same high-power hydro setup in a hot garage without better cooling and independent root-zone monitoring.

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