smokinshogun
Member
......
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IR Radiation and Water
- Thread starter smokinshogun
- Start date
thoughts, I would never mess with water and electricity for a hobby
you need to step down your bulb and employ techniques like LST , sog, supercrop. Or you need to cool your room down with higher rating air cooler. Or bump your light up and loose lumens.
you need to step down your bulb and employ techniques like LST , sog, supercrop. Or you need to cool your room down with higher rating air cooler. Or bump your light up and loose lumens.
hmm doesnt sound like the safest idea to be honest. The worst that could happen would be the weight of an aquarium hanging underneath ur hps could cause your lgiht to fall, smashing bulb, touching water - electrical fire. No the worst that could happen would be a small earthquake would cause it to fall. No the worst that could happen would be if an asteroid....ok i'm sorry.
Why not buy a thicker piece of glass. You would be amazed what they can cut to size for you in a glass shop. However, hot things emit IR. Really hot things emit alot of IR. Its the lamp and hood that are not being cooled enough, causing the whole thing to get really hot and blast IR down at you.
You say no amount of air stops the radiation - are you sure the air is being channeled through the bulb and hood as well as possible? IR wont pass through normal glass. It will get absorbed and you can cool it by convection and therefore its not getting reemitted.
Why not buy a thicker piece of glass. You would be amazed what they can cut to size for you in a glass shop. However, hot things emit IR. Really hot things emit alot of IR. Its the lamp and hood that are not being cooled enough, causing the whole thing to get really hot and blast IR down at you.
You say no amount of air stops the radiation - are you sure the air is being channeled through the bulb and hood as well as possible? IR wont pass through normal glass. It will get absorbed and you can cool it by convection and therefore its not getting reemitted.
Hi smokinshogun, I believe I can answer your question.
You correctly understand how convection works, but your layer will not do much if anything. I'll explain later why I think it may help, but I don't think it will noticeable.
As you can see the more air you move, the smaller the difference in between room temperature with the light on and what the temperature would be with the light off.
The air captures the IR waves heat energy through convection and then the air is moved to another location. Water and air behave the same way as they are both fluids. For this reason your water layer idea probably wouldn't do much if anything unless it would move the heated water to a somewhere else to be cooled.
IR waves do diffuse once passed through and water or glass and this can be noticed because it changes wave lengths and we can sense a change in color. This will result in a slight loss of intensity.
Convection will still take place with your layer of water and I believe it would work like a heat sink which I think could lower your temperatures theoretically. I'm not sure about this.
To get the temperature down you will simply need to add power fan out take. I think a professionally built air cooled reflector would be amazing if installed safely. Moving water around with pumps is a hell of a lot less noisy than moving air with fans.
You correctly understand how convection works, but your layer will not do much if anything. I'll explain later why I think it may help, but I don't think it will noticeable.
As you can see the more air you move, the smaller the difference in between room temperature with the light on and what the temperature would be with the light off.
The air captures the IR waves heat energy through convection and then the air is moved to another location. Water and air behave the same way as they are both fluids. For this reason your water layer idea probably wouldn't do much if anything unless it would move the heated water to a somewhere else to be cooled.
IR waves do diffuse once passed through and water or glass and this can be noticed because it changes wave lengths and we can sense a change in color. This will result in a slight loss of intensity.
Convection will still take place with your layer of water and I believe it would work like a heat sink which I think could lower your temperatures theoretically. I'm not sure about this.
To get the temperature down you will simply need to add power fan out take. I think a professionally built air cooled reflector would be amazing if installed safely. Moving water around with pumps is a hell of a lot less noisy than moving air with fans.
Here's a product that may solve the problem you are having. Just for disclosure purposed, I have no association with this product in any way.
Seems like a cool idea for cooling lights. You do have to buy a chiller for it tho.Thinking hard about buying one my self, but I'd have to get a 1/2 hp chiller to cool both of my 1K's.
ICE BOX Water-Cooled Heat Exchanger
The Ice Box is a safe and effective way to water-cool the air leaving your reflectors without adding a/c or more fans. It uses a water to air heat exchanger to water cool the hot air your reflectors produce. Water-cooling is much more effective and efficient than air-cooling, here's some science to prove it: Water has a thermal conductivity of 0.6 W/ (m*K) which is much higher than the thermal conductivity of air which is only 0.03 W/(m*K). Water also has a much higher specific heat capacity than air. What that means is water can absorb and remove from your garden 4 times the heat nearly 20 times faster than air! We aren't just talking about air cooling your reflectors, this goes for your air conditioning system too. Once heat is released in to your room the ability to efficiently remove that heat is lost. Air is only cooled with electricity whereas water can be cooled in dozens of ways with little or no energy. Further only 30% of the energy used in air conditioning is converted into usable cooling power, the rest is wasted. It doesn't take a rocket scientist to figure out that water-cooling will reduce your electric bill ... making your grow room a much happier place for you and your plants. In addition to cooling the heat from all those miniature suns we have in our grow rooms, if the water running through the Ice Box is cold enough, it can actually add supplemental air conditioning to your room, making them great for every operation from hut to warehouse.
Here's how it works:
The Ice Box design consists of a copper heat exchanger with a molded plastic housing. One side of the housing is designed to slip over a duct flange and the other side is designed to attach to your existing air ducting to run to an inline fan. Air from your room is pulled through your reflector just as it is now, and then over the Ice Box heat exchanger before exiting right back into the room. Cold water is circulated through the Ice Box, which is what draws the heat from the air before it exits back into your room. And a little bonus for all of us, with this device there is no need for air to enter or leave the growing environment, improving CO2 efficiency and reducing the introduction of pests, fungi, etc. Increased CO2 efficiency means lower costs for CO2 production and, for those of us burning gas to create CO2, even more control over heat production since we're not having an open flame in our rooms for quite as many hours a day. To adequately cool the air flow from a 1000 watt bulb, the circulated water only needs to be 10 degrees cooler than the ambient temperature in your room. So if you want to maintain a room temperature of 75 degrees, your water temperature only needs to be 65 degrees for the air temperature entering the reflector to be the same as the air temperature exiting the reflector. If you want to add supplemental air conditioning to your room, bring the water temperature down by more than 10 degrees and when it exits your reflector it will be cooler than the room itself. To cool the water you would need 1/4 hp minimum per 1000 watt reflector-yes, chillers use energy but not as much energy as a/c! Remember how much more efficient water cooling is over air. If additional cooling is needed for harsh environments the Ice Box itself can also be easily daisy chained for cooling power that is doubled, tripled, quadrupled. You get the picture.
Features:
Ice Box Photos
Inside View Reflector Mounting Reflector Mounting
Seems like a cool idea for cooling lights. You do have to buy a chiller for it tho.Thinking hard about buying one my self, but I'd have to get a 1/2 hp chiller to cool both of my 1K's.
ICE BOX Water-Cooled Heat Exchanger
Here's how it works:
The Ice Box design consists of a copper heat exchanger with a molded plastic housing. One side of the housing is designed to slip over a duct flange and the other side is designed to attach to your existing air ducting to run to an inline fan. Air from your room is pulled through your reflector just as it is now, and then over the Ice Box heat exchanger before exiting right back into the room. Cold water is circulated through the Ice Box, which is what draws the heat from the air before it exits back into your room. And a little bonus for all of us, with this device there is no need for air to enter or leave the growing environment, improving CO2 efficiency and reducing the introduction of pests, fungi, etc. Increased CO2 efficiency means lower costs for CO2 production and, for those of us burning gas to create CO2, even more control over heat production since we're not having an open flame in our rooms for quite as many hours a day. To adequately cool the air flow from a 1000 watt bulb, the circulated water only needs to be 10 degrees cooler than the ambient temperature in your room. So if you want to maintain a room temperature of 75 degrees, your water temperature only needs to be 65 degrees for the air temperature entering the reflector to be the same as the air temperature exiting the reflector. If you want to add supplemental air conditioning to your room, bring the water temperature down by more than 10 degrees and when it exits your reflector it will be cooler than the room itself. To cool the water you would need 1/4 hp minimum per 1000 watt reflector-yes, chillers use energy but not as much energy as a/c! Remember how much more efficient water cooling is over air. If additional cooling is needed for harsh environments the Ice Box itself can also be easily daisy chained for cooling power that is doubled, tripled, quadrupled. You get the picture.
Features:
- Engineered for maximum efficiency
- Allows you to keep a sealed room which keeps your CO2 in and pests and pathogens out
- Water approximately 10 degrees cooler than the room temp will eliminate the bulb heat from a 1000 watt lamp
- Water approximately 20 degrees cooler than the room temp will reduce or even eliminate the need for a/c
- Can be connected directly to the reflector or can be wall mounted with optional wall mount kit
- For proper function the Ice Box must be installed on the exiting air duct flange, not the incoming air!
- Air-cooled reflector and inline fan with approximately 250 CFM for maximum efficiency
- Reflectors can be daisy chained using one fan as long as each reflector gets a minimum airflow of 250 CFM
- Pump sized at 300-500 GPH with 8-10 feet of lift/head pressure
- Chiller size per 1000 watts: 1/4HP Minimum, 1/3HP Optimal
- With properly sized chiller, reservoir size of 25 gallons is sufficient for almost any set up
- For optimal performance use one IceBox per reflector
- Designed to use with 1/2" tubing
Ice Box Photos
T.Baggins
Member
HID lamps and consequently the heat that they create cannot be physically removed from the grow room, for obvious reasons, so let’s have a look at what HID lamps produce and ponder the consequences.
Heat From the Lamp
H.I.D lamps contain a ceramic cylinder (arc tube) that encapsulates a small amount of metal under strong vacuum. When the lamp is connected to the ballast and current is allowed to flow, the metal inside the arc tube reaches extreme temperatures and becomes a conductive vapor. Under these conditions the metal atoms vibrate at extreme rates and produce a spectrum of high frequency electromagnetic radiant emissions - predominantly light.
The reaction within the arc tube is highly efficient in producing light, however the lamp as a complete unit is not. The lamps structural components restrict and transform its rudimentary emissions and allow heat to accumulate. For example, some of the radiation emitted by the metal vapor is restricted by the ceramic walls of the arc tube causing it to become hot and in turn some of the emissions from the arc tube are restricted by the lamps protective glass envelope causing it to become hot. In total the lamp emits three streams of radiation - one from the metal vapor, one from the ceramic tube and one from the glass envelope.
The metal vapors inside the arc tube reach temperatures between 1100°C to 1500°C and emit radiation that is predominantly in the visible light spectrum (350 to 750 nanometers).
The ceramic walls of the arc tube reach temperatures between 500°C to 700°C and emit radiation that is predominantly in the near to mid infrared spectrum (750 to 3500 nanometers).
The glass envelope reaches temperatures from 200°C to 300°C and emits radiation predominantly in the mid to far infrared range (3500 to 6000 + nanometers).
These three emissions are the raw produce of horticultural lighting and to be successful in the fields of energy efficiency and heat reduction one must dance intuitively with all three....
After escaping the lamp, light waves in the grow room will either,
strike reflective surfaces..
pass through transparent heat barriers..
proceed towards plants without interference...
Reflectors and transparent barriers both absorb a portion of the light they receive and may become hot over time. In other words the radiant energy associated with light is able to accumulate in these components. This is an important area to scrutinize and understand, because here lays the potential to create and store heat and also the potential to minimize its production and accumulation. The Devil may lurk where light does its’ work.
For example, an 85 per cent reflective surface absorbs 15 per cent of the light that strikes it and a 95 per cent reflective surface absorbs five per cent. In practical terms, the less reflective material accumulates three times more heat and also emits 10 per cent less light. The same theory applies for transparent barriers. Cheap, thick, heat barriers (low quality glass plate or tubes) may absorb less than 10 per cent of the light they receive and hence accumulate significant quantities of heat (another potential hot spot).
Fewer watts per area gives a significant and quantifiable heat reduction, period.So it follows that a lot of heat can be eliminated from the grow room if reflectors are made from lightweight highly reflective components and if transparent barriers are made from thin, crystal clear material. For these reasons I recommend that indoor gardeners choose top quality lighting products made from the highest grade of materials.
Having identified that reflectors and transparent barriers can vary considerably in terms of quality and efficiency, one might question why gardeners don’t simplify their setups and do away with all types of light interference? There is a simple answer to this. Most indoor gardens have size; shape or functional characteristics, which require light manipulation and or light interference for effective operation. Below are some examples to help with that explanation.
Example One
HID lamps emit light in cylindrical patterns and specialized reflectors are commonly used to transform these patterns into horizontal or flat sheets of light. Flat lighting patterns are desirable because indoor garden beds are traditionally flat in shape.
Intelligently designed reflector systems compensate for the losses associated with reflection by providing a broad even light pattern that allows lights to be placed close to plants without creating dangerous heat levels. In these “flat bed” grow room designs, light and heat levels can be adjusted by raising or lowering the lights.
Example Two
Circular shaped gardens surround their lamps with plants and do away with the need for reflectors or light footprint manipulation. However, circular gardens generally require heat barriers with air cooling (cool tubes) to function reliably.
To be more specific, plants grown in circular gardens are limited by size. If they become taller than planned they could grow too close to the lamps and burn. There is very little chance for escape in this situation as the distance between lamps and plants cannot easily be increased (or decreased for that matter) in circular gardens.
I will move on quickly from light because it is heat that we are chasing. The Devil is evasive and loves to side track her pursuers.
Getting to Know Infrared (EMR 750 - 6000 + nanometers)
Just as visible light is EMR that we can see, infrared radiation IR may be described as EMR that we can feel. IR covers a wide range of frequencies, which are often split into three categories to help explain their characteristics. Up to 25 per cent of the total radiant energy emitted by HID lamps is in the IR spectrum so this is an important area for attention and understanding. Remember that a large majority of this infrared radiation is created by the arc tube casing and the lamps outer glass envelope.
Near IR (EMR 750 - 2000 nanometers) is high frequency IR radiation that has a lot in common with visible light. It will pass through glass like light but not quite as well and it will reflect like light but not quite as well, hence it transfers its energy (heat) to objects in the grow room with more vigor than light. The most interesting thing about near IR is that it is readily absorbed and transported by air.
Mid IR (EMR 2000 - 3500 nanometers) is mid frequency IR radiation. It reflects well off shiny metal surfaces and is partially absorbed by glass but what I find most interesting is that it’s readily absorbed by water and not absorbed well by air. Note: Plants are less than 90 per cent water.
Far IR (EMR 3500 - 6000 + nanometers) is low frequency IR radiation. It reflects very well off metal surfaces and glass, is absorbed by water and not by air, but what I find most interesting is that far IR has the power to penetrate biological and other solid/dense objects and create deep seated heat.
From the above information we can conclude that HID lighting is responsible for creating most of the heat in artificially illuminated grow rooms. Further we can conclude that the majority of that heat is emitted from the HID lamps and is transmitted as infrared radiation of 3 categories, Near, Mid, per cent Far IR. On top of all that we have learned that poorly designed reflectors per cent low quality transparent heat barriers can convert light to heat, store it, reemit it, and significantly increase the total amount of Mid and Far IR in the grow room.
So how do we keep our cool...
The first and most effective step in removing heat from the grow room is to reduce the amount of lamps per area, or to be more precise, the amount of lighting watts per area. Fewer watts per area gives a significant and quantifiable heat reduction, period.
Example One
If a grow room with four 1000 watt lamps is modified (without changing its size) so it requires three 1000 watt lamps to operate efficiently, the power consumption will be reduced by 25 per cent and the heat production will be reduced by 25 per cent (that’s significant).
Example Two
If a grow room with one 1000 watt lamp is modified (without changing its size) so it requires one 600 watt lamp to operate efficiently, the power consumption will be reduced by 40 per cent and the heat production will be reduced by 40 per cent (that’s massive).
By the laws of physics the above examples must achieve the power and heat reductions claimed, but what if I was to suggest that yields could be maintained or even increased in those same situations? “You’d lose light intensity and, therefore, you’d have to forfeit some yield,” I hear you say? But that’s not necessarily the case and I will explain how this can be done.
As lamps are brought closer to plants the light intensity at plant level will increase by the square of the relative distance decrease in feet (using the inverse square law in reverse). This simply means that if you bring lights two times closer you will have four times the light intensity, or if you bring lights three times closer you will have nine times the intensity.
Now if a grow light that is usually run at four feet from plants could be run (under special circumstances) at two feet, the grower who is able to utilize the two foot position would have four times the light to play with. With this amount of “free light” at his disposal he could afford to use specialized reflectors and other neat devices to spread the light and heat from the lamp all around the grow room. As a result the size of the lights useable footprint could be increased by 25 per cent to 40 per cent or even more.
This is far more than just a theory and I have proven it to work time and time again. This is an integral part of my daily business and modern growers worldwide are constantly adopting this energy efficient and heat reducing step.
The second step is to understand and work with (short wavelength) near IR. As stated previously, HID lamps produce significant quantities of near IR and near IR is readily absorbed by air. So my suggestion here would be to maintain a consistent flow of cool air around the lamp in an effort to capture most of the near IR. This would create a plume of warmed air that could be expelled from the room via exhaust fans etc or recycled (have its heat removed) via split cycle air conditioning. The main concern here is to avoid near IR absorption and its’ transformation into stored heat. Absorption and storage of near IR can be avoided using the same or similar principles as outlined above in the section.
The third step is to understand and work with (intermediate wavelength) Mid IR. You will remember that Mid IR is produced by the Lamp in reasonable quantities and also that Mid IR is created in places where light is absorbed and where energy can accumulate (Poor quality reflectors, transparent heat barriers, ducting etc). Since Mid IR is not well absorbed by air it is more difficult to remove from the grow room than Near IR. So the best way to deal with Mid IR is to avoid its production.
Because Mid IR is not produced by HID lamps in large quantities, the moderate amount that is emitted can be diluted or spread around the grow room evenly by reflection and other similar strategies.
If lighting systems are poorly designed and mid IR is created and or concentrated instead of eliminated and or spread, the consequences for associated plant life can be catastrophic. Remember, Mid IR is readily absorbed by water (it’s actually attracted to water) and plants are 90 per cent water, so my suggestion is to eliminate mid IR creation or concentration in your grow room at any cost!
The fourth step is to understand and work with (long wavelength) Far IR. Far IR is only produced in small quantities by the lamp (from the protective glass) and is most commonly created in areas where the energies from poorly reflected and or poorly transmitted EMR frequencies are accumulated. If objects that have high density and high mass are in close proximity to HID lamps they will inevitably absorb energy from light and from the lower wave length IR emissions. Airflow past the lamp and past these high mass objects will absorb some Near IR but it will do little to stop heat accumulating from light and Mid IR absorption. Thick glass “heat barriers” and heavy low quality reflectors are definitely the major contenders for the low level, high volume, heat accumulation that produces Far IR emissions.
So again, if lighting systems are poorly designed and Far IR is created and or concentrated instead of eliminated the consequences for associated plant life can be devastating. Far IR could be described as IR’s bass frequency. It can travel long distances without losing intensity, it can travel through air without losing energy, and when it strikes something dense or with high mass (a dense layer of flowering or fruiting plants) it will penetrate deeply before its energy is dissipated and transformed to heat... The deep seated heat that is created by Far IR will not be detected by measuring room temperature (air temperature) and is the common culprit when the temperature is “pleasant” but the plants look dull, tired or heat stressed.... Again, eliminate Far IR creation or concentration in your grow room at any costs!
The fifth step is the final step and the “coup de gra.” Harness the basic principles of conduction and convection to combat the negative effects of undesirable radiation frequencies in the grow room.
Vent cool air into the grow room from below the plants and let it rise gently through the plant mass towards the lights. The Near IR that is emitted from the lamps will heat the surrounding air. That heated air will naturally rise above the lights to where it can be removed from the room via the exhaust system. This starts a convection driven air current that continually draws cool air through the plants and past the lights absorbing per cent removing heat by conduction as it goes. As cool air passes through the warm plant mass it collects water vapor and cools the transpiring plants via evaporation. The water vapor there created rises past the lighting system, traveling with the air in the convection current, and is available for the absorption of Mid Infrared Radiation and Far Infrared Radiation along the way...
Heat From the Lamp
H.I.D lamps contain a ceramic cylinder (arc tube) that encapsulates a small amount of metal under strong vacuum. When the lamp is connected to the ballast and current is allowed to flow, the metal inside the arc tube reaches extreme temperatures and becomes a conductive vapor. Under these conditions the metal atoms vibrate at extreme rates and produce a spectrum of high frequency electromagnetic radiant emissions - predominantly light.
The reaction within the arc tube is highly efficient in producing light, however the lamp as a complete unit is not. The lamps structural components restrict and transform its rudimentary emissions and allow heat to accumulate. For example, some of the radiation emitted by the metal vapor is restricted by the ceramic walls of the arc tube causing it to become hot and in turn some of the emissions from the arc tube are restricted by the lamps protective glass envelope causing it to become hot. In total the lamp emits three streams of radiation - one from the metal vapor, one from the ceramic tube and one from the glass envelope.
The metal vapors inside the arc tube reach temperatures between 1100°C to 1500°C and emit radiation that is predominantly in the visible light spectrum (350 to 750 nanometers).
The ceramic walls of the arc tube reach temperatures between 500°C to 700°C and emit radiation that is predominantly in the near to mid infrared spectrum (750 to 3500 nanometers).
The glass envelope reaches temperatures from 200°C to 300°C and emits radiation predominantly in the mid to far infrared range (3500 to 6000 + nanometers).
These three emissions are the raw produce of horticultural lighting and to be successful in the fields of energy efficiency and heat reduction one must dance intuitively with all three....
After escaping the lamp, light waves in the grow room will either,
strike reflective surfaces..
pass through transparent heat barriers..
proceed towards plants without interference...
Reflectors and transparent barriers both absorb a portion of the light they receive and may become hot over time. In other words the radiant energy associated with light is able to accumulate in these components. This is an important area to scrutinize and understand, because here lays the potential to create and store heat and also the potential to minimize its production and accumulation. The Devil may lurk where light does its’ work.
For example, an 85 per cent reflective surface absorbs 15 per cent of the light that strikes it and a 95 per cent reflective surface absorbs five per cent. In practical terms, the less reflective material accumulates three times more heat and also emits 10 per cent less light. The same theory applies for transparent barriers. Cheap, thick, heat barriers (low quality glass plate or tubes) may absorb less than 10 per cent of the light they receive and hence accumulate significant quantities of heat (another potential hot spot).
Fewer watts per area gives a significant and quantifiable heat reduction, period.So it follows that a lot of heat can be eliminated from the grow room if reflectors are made from lightweight highly reflective components and if transparent barriers are made from thin, crystal clear material. For these reasons I recommend that indoor gardeners choose top quality lighting products made from the highest grade of materials.
Having identified that reflectors and transparent barriers can vary considerably in terms of quality and efficiency, one might question why gardeners don’t simplify their setups and do away with all types of light interference? There is a simple answer to this. Most indoor gardens have size; shape or functional characteristics, which require light manipulation and or light interference for effective operation. Below are some examples to help with that explanation.
Example One
HID lamps emit light in cylindrical patterns and specialized reflectors are commonly used to transform these patterns into horizontal or flat sheets of light. Flat lighting patterns are desirable because indoor garden beds are traditionally flat in shape.
Intelligently designed reflector systems compensate for the losses associated with reflection by providing a broad even light pattern that allows lights to be placed close to plants without creating dangerous heat levels. In these “flat bed” grow room designs, light and heat levels can be adjusted by raising or lowering the lights.
Example Two
Circular shaped gardens surround their lamps with plants and do away with the need for reflectors or light footprint manipulation. However, circular gardens generally require heat barriers with air cooling (cool tubes) to function reliably.
To be more specific, plants grown in circular gardens are limited by size. If they become taller than planned they could grow too close to the lamps and burn. There is very little chance for escape in this situation as the distance between lamps and plants cannot easily be increased (or decreased for that matter) in circular gardens.
I will move on quickly from light because it is heat that we are chasing. The Devil is evasive and loves to side track her pursuers.
Getting to Know Infrared (EMR 750 - 6000 + nanometers)
Just as visible light is EMR that we can see, infrared radiation IR may be described as EMR that we can feel. IR covers a wide range of frequencies, which are often split into three categories to help explain their characteristics. Up to 25 per cent of the total radiant energy emitted by HID lamps is in the IR spectrum so this is an important area for attention and understanding. Remember that a large majority of this infrared radiation is created by the arc tube casing and the lamps outer glass envelope.
Near IR (EMR 750 - 2000 nanometers) is high frequency IR radiation that has a lot in common with visible light. It will pass through glass like light but not quite as well and it will reflect like light but not quite as well, hence it transfers its energy (heat) to objects in the grow room with more vigor than light. The most interesting thing about near IR is that it is readily absorbed and transported by air.
Mid IR (EMR 2000 - 3500 nanometers) is mid frequency IR radiation. It reflects well off shiny metal surfaces and is partially absorbed by glass but what I find most interesting is that it’s readily absorbed by water and not absorbed well by air. Note: Plants are less than 90 per cent water.
Far IR (EMR 3500 - 6000 + nanometers) is low frequency IR radiation. It reflects very well off metal surfaces and glass, is absorbed by water and not by air, but what I find most interesting is that far IR has the power to penetrate biological and other solid/dense objects and create deep seated heat.
From the above information we can conclude that HID lighting is responsible for creating most of the heat in artificially illuminated grow rooms. Further we can conclude that the majority of that heat is emitted from the HID lamps and is transmitted as infrared radiation of 3 categories, Near, Mid, per cent Far IR. On top of all that we have learned that poorly designed reflectors per cent low quality transparent heat barriers can convert light to heat, store it, reemit it, and significantly increase the total amount of Mid and Far IR in the grow room.
So how do we keep our cool...
The first and most effective step in removing heat from the grow room is to reduce the amount of lamps per area, or to be more precise, the amount of lighting watts per area. Fewer watts per area gives a significant and quantifiable heat reduction, period.
Example One
If a grow room with four 1000 watt lamps is modified (without changing its size) so it requires three 1000 watt lamps to operate efficiently, the power consumption will be reduced by 25 per cent and the heat production will be reduced by 25 per cent (that’s significant).
Example Two
If a grow room with one 1000 watt lamp is modified (without changing its size) so it requires one 600 watt lamp to operate efficiently, the power consumption will be reduced by 40 per cent and the heat production will be reduced by 40 per cent (that’s massive).
By the laws of physics the above examples must achieve the power and heat reductions claimed, but what if I was to suggest that yields could be maintained or even increased in those same situations? “You’d lose light intensity and, therefore, you’d have to forfeit some yield,” I hear you say? But that’s not necessarily the case and I will explain how this can be done.
As lamps are brought closer to plants the light intensity at plant level will increase by the square of the relative distance decrease in feet (using the inverse square law in reverse). This simply means that if you bring lights two times closer you will have four times the light intensity, or if you bring lights three times closer you will have nine times the intensity.
Now if a grow light that is usually run at four feet from plants could be run (under special circumstances) at two feet, the grower who is able to utilize the two foot position would have four times the light to play with. With this amount of “free light” at his disposal he could afford to use specialized reflectors and other neat devices to spread the light and heat from the lamp all around the grow room. As a result the size of the lights useable footprint could be increased by 25 per cent to 40 per cent or even more.
This is far more than just a theory and I have proven it to work time and time again. This is an integral part of my daily business and modern growers worldwide are constantly adopting this energy efficient and heat reducing step.
The second step is to understand and work with (short wavelength) near IR. As stated previously, HID lamps produce significant quantities of near IR and near IR is readily absorbed by air. So my suggestion here would be to maintain a consistent flow of cool air around the lamp in an effort to capture most of the near IR. This would create a plume of warmed air that could be expelled from the room via exhaust fans etc or recycled (have its heat removed) via split cycle air conditioning. The main concern here is to avoid near IR absorption and its’ transformation into stored heat. Absorption and storage of near IR can be avoided using the same or similar principles as outlined above in the section.
The third step is to understand and work with (intermediate wavelength) Mid IR. You will remember that Mid IR is produced by the Lamp in reasonable quantities and also that Mid IR is created in places where light is absorbed and where energy can accumulate (Poor quality reflectors, transparent heat barriers, ducting etc). Since Mid IR is not well absorbed by air it is more difficult to remove from the grow room than Near IR. So the best way to deal with Mid IR is to avoid its production.
Because Mid IR is not produced by HID lamps in large quantities, the moderate amount that is emitted can be diluted or spread around the grow room evenly by reflection and other similar strategies.
If lighting systems are poorly designed and mid IR is created and or concentrated instead of eliminated and or spread, the consequences for associated plant life can be catastrophic. Remember, Mid IR is readily absorbed by water (it’s actually attracted to water) and plants are 90 per cent water, so my suggestion is to eliminate mid IR creation or concentration in your grow room at any cost!
The fourth step is to understand and work with (long wavelength) Far IR. Far IR is only produced in small quantities by the lamp (from the protective glass) and is most commonly created in areas where the energies from poorly reflected and or poorly transmitted EMR frequencies are accumulated. If objects that have high density and high mass are in close proximity to HID lamps they will inevitably absorb energy from light and from the lower wave length IR emissions. Airflow past the lamp and past these high mass objects will absorb some Near IR but it will do little to stop heat accumulating from light and Mid IR absorption. Thick glass “heat barriers” and heavy low quality reflectors are definitely the major contenders for the low level, high volume, heat accumulation that produces Far IR emissions.
So again, if lighting systems are poorly designed and Far IR is created and or concentrated instead of eliminated the consequences for associated plant life can be devastating. Far IR could be described as IR’s bass frequency. It can travel long distances without losing intensity, it can travel through air without losing energy, and when it strikes something dense or with high mass (a dense layer of flowering or fruiting plants) it will penetrate deeply before its energy is dissipated and transformed to heat... The deep seated heat that is created by Far IR will not be detected by measuring room temperature (air temperature) and is the common culprit when the temperature is “pleasant” but the plants look dull, tired or heat stressed.... Again, eliminate Far IR creation or concentration in your grow room at any costs!
The fifth step is the final step and the “coup de gra.” Harness the basic principles of conduction and convection to combat the negative effects of undesirable radiation frequencies in the grow room.
Vent cool air into the grow room from below the plants and let it rise gently through the plant mass towards the lights. The Near IR that is emitted from the lamps will heat the surrounding air. That heated air will naturally rise above the lights to where it can be removed from the room via the exhaust system. This starts a convection driven air current that continually draws cool air through the plants and past the lights absorbing per cent removing heat by conduction as it goes. As cool air passes through the warm plant mass it collects water vapor and cools the transpiring plants via evaporation. The water vapor there created rises past the lighting system, traveling with the air in the convection current, and is available for the absorption of Mid Infrared Radiation and Far Infrared Radiation along the way...
So TWO layers of glass AND water?
I think you're pushing in the wrong direction here friend.
If you're looking to go stealth you should seriously look into CFLs.
The easiest way to deal with most of the IR from HPS is by using flat white paint. Any dark colored material is going to absorb a lot more IR and emit heat.
Personally, if I had an HPS that was 400w or less I would buy a CMH bulb first. If that didn't cut the heat enough for my particular situation, I would look into CFLs.
You're going to find CFLs a lot easier to keep cool than HPS since there's a crapload less IR being emitted by CFLs. (I've run 150w HPS to 1000K HPS and am currently using CFLs in a stealth setup. I won't use HID for stealth without a big budget.)
It sounds like what you are looking for is an section of double glazing, with 2 holes drilled into the pvc, one for water intake and one for water output. How you'd keep the water intake flowing quickly enough or the out take slowly enough to keep the unit filled with water is one issue, whether it would be worth while is the other.
I'm still stuck on the two panes of glass reduction. Even one is a bit much and is only compensated for by being able to bring the lamp closer. Two pieces of glass and, well.... ya can't really get it any closer than right on the plants.
You really need to look at solving this with airflow and a standard cool-tube. Any money, and time, that you spend on this could be put to much better use with those technologies. Especially if you have any kind of a budget.
You really need to look at solving this with airflow and a standard cool-tube. Any money, and time, that you spend on this could be put to much better use with those technologies. Especially if you have any kind of a budget.
where did you get your glass? did you make the reflector yourself? I am sure ordinary window glass is not transparent to IR because it basically blocks all the heat when I used to have a 150w hps and now when i use cfl. Go to the glass shop and ask for 3mm window glass and see if that makes a difference.
Maybe the reflector is not diffusing the light but creating a spot beam on your hand. Light is absorbed and turned to heat on your hand.
Maybe the reflector is not diffusing the light but creating a spot beam on your hand. Light is absorbed and turned to heat on your hand.
maybe your air is too dry and theres too much airflow and this is why they are transpiring excessively: and your plants, though you dont say it are drying up? looking like heat stress?
If uve too much ventilation over the canopy with dry air you can get windburn. I almost never see people talk about this phenomenon on forums but before i took a 2yr break from growing I was using a 150W hps in 3/4 sq ft loudspeaker! I had ridiculous aparatus coming out of it, like a large acoustic duct fan and silencer - it was all a pretty hilarious setup. However, If too much ventilation went through the plants even with that light cooled excellently, the plants would frazzle. It was Real! I had to replace MUCH less air from around the plants to keep exposed leaves from drying out, whilst channelling the air flow largely through the light with glass.
If uve too much ventilation over the canopy with dry air you can get windburn. I almost never see people talk about this phenomenon on forums but before i took a 2yr break from growing I was using a 150W hps in 3/4 sq ft loudspeaker! I had ridiculous aparatus coming out of it, like a large acoustic duct fan and silencer - it was all a pretty hilarious setup. However, If too much ventilation went through the plants even with that light cooled excellently, the plants would frazzle. It was Real! I had to replace MUCH less air from around the plants to keep exposed leaves from drying out, whilst channelling the air flow largely through the light with glass.
smokingshogun, where did you get with this? Glass does not block all IR which i think i claimed.
I found a link concerning IR and plant growth- well actually its a product. Its called HEAT MIRROR™ glass. I really want to try it. http://www.alpeninc.com/features/plant/index.html
where can we get the bloody stuff?
I found a link concerning IR and plant growth- well actually its a product. Its called HEAT MIRROR™ glass. I really want to try it. http://www.alpeninc.com/features/plant/index.html
where can we get the bloody stuff?
