K
KG1
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I'm afraid the conductive heat simply runs out the tent before it's energy can heat lower air molocules which again are rushing through the tent.Damn dude, that made little to no sense. I've got science, physics and real world experience behind me. What have you got, other than ill-informed, baseless claims?
It's you who doesn't understand heat transference. If you're not concerned with, or have, heat issues; you're not trying hard enough. I don't know of any growers who don't consider heat mitigation a priority. I can't even grow in the summer months where I'm at bc of excessive heat.
Again let me see you bare handed, grab hold of any lit light bulb; from an auto tail light bulb, up to a 1,000w hps. You will burn yourself. If plant matter touches that hps bulb or led driver, it will die and turn brown
There is a reason why it's important to remove any oily finger prints from hid bulbs; it's bc the bulbs get frkn hot, and finger prints can cause hot spots that can weaken and crack, or even cause the bulb to shatter. At the very least, it will make them burn hotter and shorten their lifespan.
Here's what AI says about your last statement. I said I was growing weary of this debate:
Yeah, I can see why you’re growing weary. That comment is full of misunderstandings about basic physics and heat transfer, so let’s break it down point by point in simple terms:
1. Watts In = Watts Out (Eventually as Heat)
A 600W HPS or LED pulls 600 watts of electrical power.
Almost all electrical energy ends up as heat eventually — whether directly (infrared radiation, convection) or indirectly (light absorbed by surfaces, then converted to heat).
LEDs may be slightly more efficient, but the difference is small (maybe 10–20%). The total heat load into the room from a 600W light is still roughly 600W either way.
So the claim that "10% in heat" doesn’t make sense — there’s no magic ‘extra heat’ coming from HPS. It’s all the same energy balance.
2. Why HPS Feels Hotter
HPS bulbs run very hot at the surface (arc tube temperatures can exceed 2,000°C) and emit infrared (IR) radiation.
IR travels through air and directly heats surfaces (plants, walls, your skin) before air even warms up.
LEDs emit far less IR, so air warms more evenly and less intensely; heat is mostly at the heat sinks, which can be cooled more easily.
That’s why bare HPS bulbs “feel” hotter even if the wattage is the same.
3. Cool Tubes Absolutely Work
A cool tube isolates the bulb and ducts hot air straight out before it mixes with the room air.
This prevents convective and radiant heat from accumulating in the grow space.
If they “made zero difference,” commercial growers wouldn’t spend thousands on them.
Real-world data:
A 600W HPS without cooling easily pushes temps 10–15°F higher in a small tent.
With a cool tube or air-cooled hood, you can cut that by half or more because you remove the heat before it spreads.
4. One Light Still Needs Cooling
Saying “one light in a tent doesn’t need cooling” is wrong.
Small tent + 600W light + little airflow = temperature spikes.
Many small growers actually switch to LEDs just to reduce heat load because cooling small rooms is hard.
5. Why Some People Don’t Notice Heat Problems
If someone grows in a cold basement or big drafty garage, heat might not be an issue.
But in a small, sealed tent in summer, 600W of heat quickly overwhelms ventilation.
Claiming “HPS growers never complain about heat” is false — it’s one of the most common problems on grow forums.
Bottom Line
Watts in = watts out as heat, but HPS dumps it as intense IR radiation + convection.
Cool tubes work because they prevent that heat from ever entering the grow room air.
LEDs distribute heat differently, which makes cooling easier, even at the same wattage.
Whether heat is a problem depends on room size, airflow, and ambient temps, not just watts.
It's not just the power of heat it's the air velocity which gives a final figure and that is small in both cases.
But now we talk radiation as in light, well you can't cool that till it hits a surface, I can't simply suck with air it's value out it needs to transfer into another form of energy.
Ok cool tubes removed a very small amount of heat, nothing a small tent growers can notice, I stand under any light in a wind tunnel and place a piece of glass between me and the light I feel very little if any difference. Only at low enough wind speeds that the energy held in the air round the bulb can it make the journey from the bulb to me otherwise it's moved away far too quickly.
Air is highly effective at cooling, water even more so but since in a tent I'm already running exhaust at a rate that far exceeds the wattage needed to heat the volume of air before it is exchanged.
Unfortunately the transference of enough radiation to a thin leaf surface can be enough to heat it past biological function and that we can't cool with a cool tube and in small tents is more the issue as is air temperature you suck in and through the tent.
The above about air suction shows it's efficiency in removing air from a tent, in fact the air coming in is barely heated by more than a degree or two by the time it leaves after mere seconds in there.
Don't really see any heat difference if I'm running the equivalent light radiation, 600w is certainly not heating 200 cubic feet by much in a minute you can place a 600e any light in that sized room and wait for that answer.
How is a cool tube valid and how can I see a savings on cooling and led unless I scale up my grow to a big room full really?