New Grower More Heat From 150 HPS With Internal Ballast or 250 HPS With External?

[cooldm]

Hey guys,

Had a great discussion with my last thread so I'm hoping you guys can help me out with another problem.

I currently use the Floralux 150w HPS and it works great for my grows. The only downside is that it has an internal, non detachable ballast which gets pretty hot. I've heard of some people disassembling the unit to make the ballast external but I'd rather not go down that route. I've looked at some 250-400 Watt systems with an external ballast that might help me with the problem.

Has anyone out there upgraded from 150 to 250-400 with an external ballast and noticed a change in temperature? Would appreciate any input :smoke:.

 

[late]

What's the size of the grow space?

You will get more heat with the internal. My external 400w ballast gets quite warm.
A rule of thumb is 50watts/sq foot. I have 8 sq feet and 400 watts. I started with a lot
less, and more makes sense if you are maxxing out the plant's metabolism.

Sounds like you will need better ventilation. I have a good ventilation set up, and I am going
to shut it down for the summer. It will get too hot in there.

 

[A4]

I haven't ran anything that small but any time you can get the ballast out of the grow room it is going to help. I would recommeng going to a digital 600W that can be turned down to 400 or less. I have a lumatek 600 that i turn down all the time and it still has the power to use if you decide to expand. Keeps from buying a lot of extra equipment. You can buy 1 600W bulb and use it for all wattages. Just a thought.

 

[dirty budster]

From what I read the power loss in the ballast is between 10 and 20%. In your case with a 150W bulb that would be between 15 and 30W. Worst case you will have a total power of 180W with the 150W HPS+ballast. The temperature will increase if you switch to a 250W bulb even if the ballast is external.

 

[cooldm]

What's the size of the grow space?

You will get more heat with the internal. My external 400w ballast gets quite warm.
A rule of thumb is 50watts/sq foot. I have 8 sq feet and 400 watts. I started with a lot
less, and more makes sense if you are maxxing out the plant's metabolism.

Sounds like you will need better ventilation. I have a good ventilation set up, and I am going
to shut it down for the summer. It will get too hot in there.

Thanks for the reply.

Grow space is 2.5' by 2.5' tent inside a 4' by 4' closet. I also supplement with about 150 watts of CFLs. Ventilation is a bit of a problem (as this is also stealth) but the closet has an attic crawl space so I have a box fan over that space exhausting the air up. Putting the ballast right below that I feel would help immensely instead of keeping one in a tent.

- - - Updated - - -

I haven't ran anything that small but any time you can get the ballast out of the grow room it is going to help. I would recommeng going to a digital 600W that can be turned down to 400 or less. I have a lumatek 600 that i turn down all the time and it still has the power to use if you decide to expand. Keeps from buying a lot of extra equipment. You can buy 1 600W bulb and use it for all wattages. Just a thought.

Yeah, I figured getting an external would make it cooler but would it be enough to justify getting a new unit. I've pointed an IR Thermometer at my 150 while it's on and the ballast was hitting 150 while the light seemed to be around 120. I've thought about getting a 400 that can turn down to 250. Anything above 400 for my 2.5 by 2.5 tent seems overkill for now and I don't think I'll ever expand out of it.

- - - Updated - - -

From what I read the power loss in the ballast is between 10 and 20%. In your case with a 150W bulb that would be between 15 and 30W. Worst case you will have a total power of 180W with the 150W HPS+ballast. The temperature will increase if you switch to a 250W bulb even if the ballast is external.

So you're saying the overall temperature would go up with an upgrade even if an external ballast was placed outside the tent? I took temperatures of my 150 with an IR thermometer and noticed the ballast runs around 150 and around the bulb stays around 120. I'm not sure what a 250 bulb on it's own would run at, any idea?

 

[Taviddude]

Thanks for the reply.

I took temperatures of my 150 with an IR thermometer and noticed the ballast runs around 150 and around the bulb stays around 120. I'm not sure what a 250 bulb on it's own would run at, any idea?

If that a HPS bulb, it isn't running at 120. Wrap your hand around that puppy once, lol.
Move up to a 400 with dimmable external ballast. Run it at 50% and see if you can work your way up.
Get a cooltube hood, and run the exhaust up into your attic. With a fan cooling your light, and pulling in fresh air constantly I don't see that small of a space heating up even with 400 watts unless your house isn't air conditioned.

 

[cooldm]

If that a HPS bulb, it isn't running at 120. Wrap your hand around that puppy once, lol.
Move up to a 400 with dimmable external ballast. Run it at 50% and see if you can work your way up.
Get a cooltube hood, and run the exhaust up into your attic. With a fan cooling your light, and pulling in fresh air constantly I don't see that small of a space heating up even with 400 watts unless your house isn't air conditioned.

Yes, I am aware the bulb isn't running at 120 which is why I said, "around the bulb". Just like the 150 temperature isn't of the ballast itself, just the metal casing around it. Unfortunately, a cooltube hood isn't much of an option as this is a fairly stealth setup and inline fans can run pretty loud. Would be nice to run that into the attic as I feel that would solve the majority of the problems but the noise from the fan and the airflow noise itself would just be too much.

 

[dirty budster]

So you're saying the overall temperature would go up with an upgrade even if an external ballast was placed outside the tent? I took temperatures of my 150 with an IR thermometer and noticed the ballast runs around 150 and around the bulb stays around 120. I'm not sure what a 250 bulb on it's own would run at, any idea?

In short, yes. The longer answer is that HPS bulbs turn about 70% of the input power into heat. In your case comparing a 250W bulb with a 150W+ballast, assuming 15% power loss in the ballast would give:

250W*0.7 = 175W of heat
150W*0.7 + 22.5W from ballast = 127.5W of heat

Physics says the temperature will increase and I would be very surprised if that weren't the case.

 

[cooldm]

In short, yes. The longer answer is that HPS bulbs turn about 70% of the input power into heat. In your case comparing a 250W bulb with a 150W+ballast, assuming 15% power loss in the ballast would give:

250W*0.7 = 175W of heat
150W*0.7 + 22.5W from ballast = 127.5W of heat

Physics says the temperature will increase and I would be very surprised if that weren't the case.

I appreciate the explanation but there are a couple of things off with this calculation.

First, the 150 watts is just the power drawn by the bulb. The whole unit itself pulls about 200. The specs for the ballast states 1.65 amps at 120V.

Second, the loss in the ballast doesn't necessarily translate to a loss in heat, just lumens. The inductors and capacitors that account for the loss in the ballast will still produce heat.

 

[Gadgetguy]

Careful ventilating into an attic that has wild temp swings, especially in the winter. If the attic isn't ventilated or you don't vent up through the roof you can have mold issues, ask me how I know lol. Condensation is no fun.....