Close Encounters - Air Cooled Lighting Systems

Close Encounters - Air Cooled Lighting Systems

Tim
Tim
28 Aug 2011

It happens every year. Summer arrives, temperatures climb and it's tough to keep plant  healthy - especially you've got limited headroom.

If you’re growing through summer, there’s one foolproof way of removing heat – air cooled lights.

There’s no stopping them! Up and down the country they’ve made grow room temperatures more and more manageable. All while giving an even spread of light.

How They Work

Your lamps are a big source of heat.

Air cooled reflectors have a glass bottom to create an air tight tunnel. Cool air is blasted through this tunnel and over your lamps to remove heat.

Next to no light is lost through the glass panel - just make sure you keep it clean.

It's the perfect answer to your warm weather woes!

Sputnik Sputnik

Why you Need One

Removing heat in this way has some serious advantages:

  • Prevents heat build ups in summer months
  • Stops hot spots forming around your lamp
  • You can lower lights without burning plants
  • Solves heat problems in a small spaces (e.g. cellars & cupboards)
  • Reduces the ventilation rate by up to 25-30%
  • Helps you reach the optimal lighting wattage in your area
  • Stops you extracting added CO2, as you extraction less air from your grow room

The Myths

The rumour mill's been grinding - here are a few porkies you might have heard about air cooled lights.

Sputnik Sputnik

Too much light is lost through the glass panel

Some growers worry that too much light will be lost through the glass plate.

New, good quality flat glass will reduce intensity by 4-5%. However, most growers who don't use an air cooled reflector will raise their light height and dim their intensity. Doing this reduces light intensity way more than an air cooled reflector does.

To minimise light loss from the glass panel, keep it clean and keep the reflector closer to the plants. Bear in mind that lowering your light height  may also effect distribution and uniformity - particularly with Cool Shades.

You can mount air cooled reflectors much closer to your plants

There's some truth in this. You can bring your reflector much closer to your plant without burning them....BUT that doesn't mean you should.

The closer the reflector sits above the canopy, the smaller the area of illumination. Always aim for the optimal hanging height to get an even distribution at the ideal intensity - 800-950 micromoles/s.

The colder the air you blow through the reflector, the more it cools

This is true, but you don't want to cool the lamp and reduce the light output. The gasses in the arc tube for HPS lamps needs to get up to temperature to emit light at its optimum rate. Your goal is to remove excess heat - not dim the light by cooling the lamp. Air at a similar temperature to the grow room best suits air cooled lighting.

Air cooled reflectors remove all the heat generated by the bulb

Not quite. HID lamps  generate 2 types of heat: convection and radiation. Moving air past the lamp significantly reduces the convective heat, but can't remove radiated heat.

What you Need

For an air cooled lighting system, you need 3 things:

DARKSTAR DARKSTAR

1) Air Cooled Lighting System

  • Air Cooled Reflector
  • Lamp
  • Ballast

We recommend buying a complete DARKSTAR or Cool Shade Lighting System.

DARKSTAR DARKSTAR

2) Air Cooled Lighting Kit

  • Extraction Fan - blows air through the ducting and over your lamp
  • Ducting - carries the air
  • Duct Clip - connects the ducting to the reflector and fan

We recommend buying a complete 125mm Air Cooled Lighting Kit or 150mm Air Cooled Lighting Kit.

DARKSTAR DARKSTAR

3) Hanging Accessories

So you can  suspend the system from a grow tent roof pole or ceiling. We recommend some Rope RatchetsS-Hooks and Hook Plates.  

Reflector Options

There are two choices.

DARKSTAR DARKSTAR

Premium: DARKSTAR Air Cooled Lighting System

For a really sturdy system, you want a DARKSTAR. 

  • Heavy duty case to protect the lamp, reflective material & glass
  • Easy inspection & cleaning with hinged glass and safety latches
  • Arrives fully assembled -  it's ready to go as soon as you open the box
Cool Shade Cool Shade

Budget: Cool Shade Lighting Systems

The Cool Shade is one of the first air cooled lights ever made. It's still a firm favourite, and is great if you're sticking to a budget.

  • Huge bargain
  • Clip on reflector

125mm or 150mm?

The more reflectors you use in one room, the higher the air flow you need. If you need high air flow, it's best to have bigger 150mm spigots to reduce air flow resistance.

Setting Up

Setting up isn't difficult. You just need to make sure you have the right airflow, blowing in the right direction.

Suck or Blow?

To make sure you don't get any untreated, smelly air sucked into a reflector's ventilation system, you should always blow through it. This means if there's any positive air pressure, air will seep out of your system, not into it.

What Air Flow?

The air flow you need depends on how easy air can move through the reflector, the pressure loss caused by the ducting run and the wattage of the light(s).

Darkstar airflow Darkstar airflow


For a Cool Shade, air flow is quite unrestrained, due to the low resistance design. You should aim for between 100-200m
3/hour of air flow per 600W reflector.

Darkstar airflow Darkstar airflow


For a DARKSTAR, where the flow of air is slightly more turbulent because of the box shape, between 200-300m
3/hour is about right. 

Connection in Series

You can connect up to 3 together. At a stretch, you can go up to 5. More than this and the first reflector will be cooler than the last.

Darkstar airflow Darkstar airflow


Connect reflectors in a series, separating them with ducting.

Darkstar airflow Darkstar airflow


You may need to use multiple smaller fans or Y's and Tee's in large rooms with a series of air cooled lights.

Darkstar airflow Darkstar airflow


You can use the extractor fan to blow filtered grow room air through the air cooled reflectors. This suits small rooms where thermostatic fan speed control is not needed.

Tim
Tim
About the author

Tim started out in Dudley but is now the manager at Bristol! Drop by and you'll probably see him there.  

GroWell Hydroponics Bristol

Call GroWell Bristol
0117 955 8404