LED vs HPS grow lights

High-pressure sodium lamps made a generation of indoor flower rooms possible. They put out a lot of light in the yellow and red, and they put out a lot of heat with it. A modern LED bar is what BAVAGREEN quotes first for a new tent, because more of each watt becomes photons, the spectrum can be shaped, and a dimmer replaces the old habit of raising the lamp until it hits the ceiling.

This is a buying comparison. It is not a wiring guide, and it is not a schedule for any one crop. Match voltage, mounting, and ventilation to the fixture datasheet before you power anything.

What the watts are doing

An HPS lamp turns a share of its electricity into visible light and a large share into heat at the bulb, the reflector, and the ballast. The tent then needs enough exhaust to hold leaf temperature in a range the plants can use. In a small tent that often means a strong fan, a lot of duct, and a room that can accept the warm air.

An LED bar still makes heat. Drivers and diodes warm up, and a closed tent will climb if the air does not move. The difference buyers feel is that a larger share of the wall power shows up as light, so the same photon target often needs less exhaust than the sodium lamp it replaces. Many tents can then run a smaller fan, or run the same fan slower. "Smaller" is not a promise. Measure the room. The 80×80 kit publishes a 4-inch EC inline fan at 212 CFM and a 6-inch clip-on fan with its 240W bar. The 2×2 kit publishes a 4-inch EC inline fan and a 6-inch clip-on fan. The 3×3 kit and the 4×4 kit publish a 6-inch EC inline fan at 410 CFM and a 6-inch clip-on fan.

If you are leaving HPS, plan the fan with the new lamp instead of assuming the old exhaust is now too big or still too small. Tell sales the tent size and the ambient temperature.

Spectrum you can switch

HPS is a broad yellow-red lamp. Growers learned to flower under it, and many still do, because that spectrum is strong in the bands plants use heavily in flower. It is a weak lamp for judging leaf color. The room looks orange. Early growth under HPS alone is often stretched unless the lamp is far away or the photoperiod and temperature are managed carefully.

A BAVAGREEN LM301H EVO bar starts with white diodes, then adds 660 nm red. The white base is usable from seedling through flower, and you can see the plants. Far-red at 730 nm and UV are extra channels with their own switches on the Pro bars. They can stay off while the canopy is young and come on later. That is a different idea from a single sodium bulb that is either on or off.

The published 600W sheet lists 3000K, 5000K, 660 nm, 730 nm, and 385 nm UV. The 240W bar is listed as mint-white LM301H EVO plus red, far-red, and UV. Read the LM301H EVO page and the UV and far-red page before you treat those extra diodes as the main light. The white and red base is the lamp. The extra channels are supplemental.

Efficacy is a fixture number

Diode efficacy and fixture efficacy are different. BAVAGREEN's published bars quote about 3.14 µmol/J at the LM301H EVO diode and about 2.90 µmol/J for the whole fixture. The fixture figure is lower because the driver, the red, the UV, and the far-red are inside the measurement. Use it when you compare lamps.

On BA-600W-PLUS that fixture figure is 1740 µmol/s at 600 W, listed for a 120×120×200 cm tent. On the 240W PLUS it is 696 µmol/s at 240 W. Those are manufacturer figures for those models. Confirm the datasheet. They do not transfer to a different wattage, and they are not a claim about how an HPS lamp of the same wattage behaves.

A 600W LED and a 600W HPS can share a number on the box and deliver different amounts of light and very different amounts of heat. When you replace sodium, compare photon output and the heat you have to remove, not the wattage sticker alone. The 4×4 watts guide walks through why a 600W efficient bar sits in the middle of the usual planning range for that floor.

Dimming and day-to-day use

HPS dimming, where it exists, is often coarse, and many rooms simply run the lamp at full power and change the hanging height. In a tent with a low ceiling, height runs out. Seedlings end up too close, or the lamp ends up in the roof poles.

The published BAVAGREEN bars dim from 0–100%. You can drop intensity for seedlings and raise it as the canopy fills, then use height as a second adjustment. The distance chart gives generic starting ranges for a modern LED bar. It is not a PPFD map, and it is not a clearance for an HPS bulb. Sodium lamps have their own heat pattern. The distances in that lamp's manual are the ones that matter if you are still running one.

There is no calendar lamp swap on a fixed LED bar. Drivers and diodes still age. Ask for the warranty on the model you order, and ask what "wattage" means on the label: wall draw, or a marketing equivalent of an older lamp. BAVAGREEN's published sheets use real draw, 240 W and 600 W.

When each one still fits

For a new tent, a dimmable LED bar is the default quote, because the tent, the light, and the fan can be sized together. Use the bar range and the kit index. A 2×2 stays in the 240W class. A 4×4 starts from BA-600W-PLUS. A 3×3 is confirmed between those two published bars.

HPS can still be the right tool in a room that is already built around it: the ballasts are mounted, the reflectors are aimed, the exhaust is sized for that heat, and the crop program is written for that spectrum. Replacing one lamp in a row of sodium with one LED bar changes the light and the heat in that bay only. A whole room is a project. The commercial page is for repeating a published fixture. The OEM page is for a private-label bar or a layout that has to match an existing controller.

What to ask before you switch

Send four facts: the tent or room size, the lamp you have now and its true wall draw, the exhaust you already own, and the mains voltage. Input on the published bars is AC 85–265 V, and the plug still has to be confirmed for your country.

Ask for the PPFD map of the exact model, the hanging method, and whether UV and far-red ship enabled. If you want the tent as well, name the footprint: 2×2, 3×3, 4×4, or the 80×80 set. Sales replies with a packing list. This website does not take payment and does not tell you how to wire a ballast.