I bought a GL60 tent, which measures 24"x24"x53". I plan on separating it into a small veg chamber on bottom and larger flowering chamber on top. Obviously, being a small space, heat is a concern -- in my current tiny homemade cab my 150W HPS will raise temps to 105 in a couple of minutes without my fan on. CMH bulbs are appealing to me because my understanding is that they emit less heat. Can anybody attest to how much less? How does, say, a 150W HPS compare to a 250W CMH?
How much cooler is a CMH?
- Thread starter Vache123
- Start date
sixteenounces
Well-Known Member
Vache, a CMH isn't going to put out much less heat than a normal MH maybe 2 - 5 degrees at most.
I Use a 400W CMH and a 400W HPS and i get lower temps inside my vented hood with the HPS! i believe this is because the bulb is more aerodynamic, and allows for slightly better cooling inside the hood.
I Use a 400W CMH and a 400W HPS and i get lower temps inside my vented hood with the HPS! i believe this is because the bulb is more aerodynamic, and allows for slightly better cooling inside the hood.
8deez8
Active Member
im going to have to disagree. Traditional metal halides throw a LOT of heat, way more than HPS. My CMH, with no cool tube, can be placed 8 in from tops no problem, and is the coolest operating HID Ive ever seen.
Im not familiar with the smaller wattage HPS bulbs, but it goes something like this
MH heat>HPS heat>CMH heat
I would be willing to say that with a remote ballast you could go from 150w HPS to 250w CMH with only marginal increase in heat. CMH's have much lower convective heat, but about the same radiant heat. In other words, if you are using cool tubes then you will not notice too big of a change. If your bulbs are not air cooled, you will notice a big difference in the heat. They are a great bulb to reduce heat, you WILL notice a major drop in unwanted heat if you do not use cool tubes.
Im not familiar with the smaller wattage HPS bulbs, but it goes something like this
MH heat>HPS heat>CMH heat
I would be willing to say that with a remote ballast you could go from 150w HPS to 250w CMH with only marginal increase in heat. CMH's have much lower convective heat, but about the same radiant heat. In other words, if you are using cool tubes then you will not notice too big of a change. If your bulbs are not air cooled, you will notice a big difference in the heat. They are a great bulb to reduce heat, you WILL notice a major drop in unwanted heat if you do not use cool tubes.