Mars-Hydro description of their lights

[Nunyabiz]

Says it replaces an 800w HPS.
And they clearly made a mistake in saying it draws 740w.
They no doubt meant to say 540w which would fit the usual 30% less power draw for LEDs vs HPS.
It has roughly 600 PAR at 18"
If you get 600 PAR at 18" then its certainly better to only use 570w .
It's just a mistake on the current draw in your favor.
What would piss me off is if they said 540w and it actually drew 740w to get the stated PAR or if its actually 540w but only puts out 400 PAR.

In this case the mistake is in your favor

 

[JelitoKopito]

Wow, that's... about 43 square feet, so I can pretty much answer that question with a, "Yes," without even stopping to ask which light the question is in regards to. It's also four times as long as it is wide, and that is another potential issue when using ONE light - even if you have a light source that produces enough photons, you'll tend to end up in the situation where you'll be lighting up two opposing walls, insufficiently illuminating the area nearest the other two walls, or possibly both. And that kind of thing cuts into your... "lighting efficiency," or whatever you want to call it.

I was expecting this that light efficiency wont be as good as squered room but I have this so that will have to do it.7

Thats why I bought light mover for area of this proportions. I think it was good idea.



Do you pay rent by the cubic meter, lol? Otherwise, I don't see the problem. Grow sativas, problem solved . LEDs basically shine in one general direction, so as long as you haven't installed the thing upside-down, that device's (light) output is going to be aimed in the general direction of the plants. It shouldn't matter whether there's a reasonable minimum clearance above it or the grow space is in a disused 100-story elevator shaft.

To this part - I only asked cuz I read somewhere that it could cause higher temp when there is too much space above light.

 

[Dwight Monk]

I know that its possible to make extraction fan to led lights but this light have air input on top and output on sides

Heat rises so as long as you are drawing your air for extraction out of the top of your space you are removing heat. Pretty sure they just meant that and not something hooked up directly to the light.

 

[Virgin Ground]

I know that its possible to make extraction fan to led lights but this light have air input on top and output on sides

What size extraction fan are you using for this tent? Positioning fans to blow between the lights and the canopy and making sure you have enough pull from your extraction fan will help.
If your tent is already in a warm room you may have to add air conditioning to the mix.

 

[JelitoKopito]

Says it replaces an 800w HPS.
And they clearly made a mistake in saying it draws 740w.
They no doubt meant to say 540w which would fit the usual 30% less power draw for LEDs vs HPS.
It has roughly 600 PAR at 18"
If you get 600 PAR at 18" then its certainly better to only use 570w .
It's just a mistake on the current draw in your favor.
What would piss me off is if they said 540w and it actually drew 740w to get the stated PAR or if its actually 540w but only puts out 400 PAR.

In this case the mistake is in your favor

is it a lot or less 600par for 18?

 

[JelitoKopito]

What size extraction fan are you using for this tent? Positioning fans to blow between the lights and the canopy and making sure you have enough pull from your extraction fan will help.
If your tent is already in a warm room you may have to add air conditioning to the mix.

Im using big 50w fans cuz of size of the room.
fast sketch of my room
light is attached to light mover

 

[Virgin Ground]

Put your out put ducting at the top of the tent. Heat rises so you want that positioned high in the tent. I would switch the fans around to the opposite side of where they are positioned now. This should give you a nice airflow and point most of the hot air toward your extraction point.

 

[JelitoKopito]

Put your out put ducting at the top of the tent. Heat rises so you want that positioned high in the tent. I would switch the fans around to the opposite side of where they are positioned now. This should give you a nice airflow and point most of the hot air toward your extraction point.

so you say I should make those 2 fans blow air straight to wall to create airflow of whole room?

 

[JelitoKopito]

Put your out put ducting at the top of the tent. Heat rises so you want that positioned high in the tent. I would switch the fans around to the opposite side of where they are positioned now. This should give you a nice airflow and point most of the hot air toward your extraction point.

I have ducting output at bottom cuz I dont know how to hide it on top (you think that it makes a big difference?)
Hot air from top is pushed trough ducting with strong fan.

Output fan is laying so it suck hot air right from top of the room and part of fan which makes wind is connected to ducting which goes out of the room

at bottom ducting output is hidden behind my table

 

[Virgin Ground]

It make a lot of difference. My plants grew too tall and I had to put my carbon filter on the floor. I battled high heat throughout flower and my buds were not as dense as they should have been. 10-20 degrees is a huge difference.

 

[JelitoKopito]

so when you take air from bottom you got higher temp right?

I cant think why it should make big difference if you mean same thing as me.

Here is more detailed sketch of how its placed.

Fan is placed around 2m above ground (but room is like 2.8 tall)
and end of ducting which ends outside growing room is like 40cm above ground.

 

[JelitoKopito]

nothing from that company is tier one except for the con they are pulling.
240 actual watts is alot to be ripped off for

yes it is.... led light for begginers could have 200w and they ripped me off for it

 

[JelitoKopito]

It make a lot of difference. My plants grew too tall and I had to put my carbon filter on the floor. I battled high heat throughout flower and my buds were not as dense as they should have been. 10-20 degrees is a huge difference.

check the pic pls. and others tell me if there is really difference about ducting ending at top or at bottom

 

[Oldbear]

hey Jelito One thing to research with lights is the size of the 'sweet spot' on the light. This dimension helps to determine how many lights needed for the size of your space.

There may be viewable light in the corners, but its not strong enough for effective plant growth.

The height of the light above the plants also has an effect on yield and quality.

 

[Oldbear]

check the pic pls. and others tell me if there is really difference about ducting ending at top or at bottom

The key with ventilation and heat control is that the intake needs to be up high. The height of the exhaust point doesn't matter.

 

[Carcass]

Well yes but you cannot move that heat from your grow room.

but this light have air input on top and output on sides

As most of them do...fortunately,heat rises,so an exhaust fan above the light will remove
most of the heat produced by the light...even if the light moves around,the heat still ends up at the top of the tent.
Without a fan the heat will fill the tent, from the top down- so you need an exhaust fan at the top of the tent,and either an intake fan,or passive intake vents (openings) at the bottom of the tent to replace the air being sucked out at the top.
This is what works for me,it's not the only way,but it is one way that works

 

[LiberalThinker]

Yes. I'm wondering if 420mag staff should insist to its light sponsors that they only advertise watts at the wall for their lights. This issue is arising so often, it should be dealt with. It's dishonest.

 

[Oldbear]

Is there actually a direct co-relation to watts at the wall and the quality and plant useability of light produced?

On one hand I can hook up a 500 watt floodlight that wont grow a rock.

 

[LiberalThinker]

Is there actually a direct co-relation to watts at the wall and the quality and plant useability of light produced?

On one hand I can hook up a 500 watt floodlight that wont grow a rock.

No, but with specialised grow lights the watts gives you an idea of the potential as long as you know the other necessary parameters, like ppfd, spectrum etc, as well.

 

[Skunks]

The key with ventilation and heat control is that the intake needs to be up high. The height of the exhaust point doesn't matter.

So are u saying I take hose should be higher up as mines at the bottom?