How Can I Minimize my Heat Signature?

Smokin Moose

Fallen Cannabis Warrior & Ex Moderator
Infrared cameras are widely used by law enforcement for border patrol, grow room confirmation, and other surveillance operations. There is legal debate as to whether this technology is intrusive or non-invasive.

Growers fear IR because it?s difficult to ?hide? invisible heat. Protecting yourself against excessive heat emissions is a good defensive measure. This FAQ focuses on masking heat emissions.

What is infrared?
Light and heat energy warm objects, which then re-radiate excess energy. Some of this excess energy is emitted as low-energy infrared. IR is invisible to the naked eye, but can be displayed and measured by specialized cameras.


What does Leo look for?
Officers are trained to look for hot spots on walls and windows, unusually warm foundations, exhaust emissions from vents and chimneys, and warming trends typical of marijuana grow operations. Leo will wait until evening or early morning (when the grow is up to full temperature and the air is cool). He will also look for light leaks, smells and other info at this time.

Note: Leo will try to image a suspected grow-op from all angles, but is only legally able to do so from public property (ie. Sidewalks, roads, public paths, etc).

Noteower companies occasionally image power pole transformers to see if they are abnormally hot (problems), and to source power theft.

Legal implications
(ExpensiveCloset) "A thermal imaging scan does not intrude in any way into the privacy and sanctity of a home?the privacy associated with a home, are (not) threatened by thermal imagery." (US supreme court ruling)

"The Supreme Court ruled 5 to 4 on June 11 [2001] that police cannot use infrared heat-detecting technology to gather evidence from a private home without a search warrant" High Times, October 2001 (Pg.20)

In Canada, IR is used in the pre-investigation phase. Positive results can then be used to obtain a search warrant.

Will Insulation help?
Conventional insulation will help block IR, but it is probably not enough by itself. A fully insulated wall (R 40) will hold heat much longer than a window (R 2). Concrete is a good conductor of heat; after hours of HID lighting, foundations will become abnormally warm.

Most growers flower at night to take advantage of the naturally cooler air; unfortunately, a warm grow house will radiate lots of thermal energy compared to the cool night air.

How do I mask my heat emissions?
Note: Small grows (under 2000w) would probably not emit enough heat to warrant the effort or expense.

Note: Reducing grow room temperature will reduce heat emissions; however, the grow room will still be warmer than surrounding basement rooms.

This technique creates a false wall to contain cold air. Interlocking rigid foam panels prevent hot grow room air from contacting and warming house walls. Cold air is blown into the gap between the foam and the walls for maximum protection. The wall?s exterior will appear ?cold? to an IR camera, indicating a negative for internal heat.

· "Partial room" (insulate exposed walls only)
· "Room in a room" (entire rooms are insulated)

*Floor. Concrete foundations absorb heat readily. Build a sub floor to raise the entire grow off the floor.

*Walls. Use interlocking 1.5 or 2? foam insulation along all exposed walls. Place the insulation 1-4? away from walls, fit foam panels from floor to ceiling (some cutting may be required), and blow cold air into the gap. Seal seams and corners with tape. Cover walls with Mylar to reflect heat back into the room.

*Windows. Windows are essentially uninsulated, so you must fill the gap with insulation. Draw the curtains/blinds, add black poly behind, then add insulation.


Drawing descriptionpartial
A ? Public property that Leo can image from

B ? Internal basement room. Grow room heat will still be noticeable, and this side needs protection.

C -- ?Safe? basement rooms. Put ballasts and reservoir outside to minimize heat

D ? Partially insulated growroom. The pink band is the interlocking foam insulation, the blue band is the cold air contained between the insulation and the house walls. The window on the bottom of the picture can be open to allow cold air to enter the air gap. Room temperature air can also be blown in from an adjacent basement room through a hole in the foam panels.

Hiding the Exhaust
Safely exhausting hot air is difficult; Leo looks for unusual heat emissions coming from opened windows, chimneys, dryer vents and other handy places. Note: running exhaust to outside sheds, barns and tree stumps is well known to Leo.


Every house has a sewer vent standpipe. By venting down the sewer, the exhaust will be chilled and smell is distributed amongst you and your neighbors. The sewer cleanout access is often a 3-way 4? abs ?T? with a threaded cap somewhere in the basement. Remove cap, and hook your blower to the T (A 4? to 3? adapter funnel may be required) and run blower 24/7. This will not affect normal use of the sewer

Cool exhaust with water
Place a wet towel (wicking water from a tray underneath) partially over the end of the exhaust. Spraying water inside the exhaust pipe works as well.

Underground exhaust
Running the exhaust through a long, buried pipe helps to cool the air. Perimeter drains can be used for this.

Water-cooled lights
Running water cooled lights is very effective; IR heat from the lights are washed down the drain. Water cooled light systems are currently difficult to source, and have drawbacks including cost, condensation and leaks.

Tools for the grower:
Note: most ?night vision? devices use UV (ultraviolet) and not longwave IR detection.

Engine heat ?guns?. +/- 1F. Numerical readout, laser pointer.
"Night Vision" scopes, cameras and camcorders.
Infrared film (Kodak High Speed Infrared Film 2481)
 
My first house I vented out the flu. I had all gas, so there was a reason for the the heat. After a few years we went to all electric. So I vented the heat from my grow room to a dark part of my yard. I had to dig a trench for the draining of my yard, so one night I dug a 2x2 square hole and filled with 1/2 inch aggregate. The vent emptied in there and then would be dispersed into the earth. Was easy to do when they was doing the yard drainage. May be hard to do if you decide to do it and have no reason. Plus I went and purchased 4 IR illuminators and some IR security cameras. After it was all installed NightVision and Ir cameras are useless as the whole area is awash in IR light. I got the idea after the company installed my home alarm system had installed the IR illuminator and IR cameras at the doors. Plus I live next to the presiding Judge.
 
My first house I vented out the flu. I had all gas, so there was a reason for the the heat. After a few years we went to all electric. So I vented the heat from my grow room to a dark part of my yard. I had to dig a trench for the draining of my yard, so one night I dug a 2x2 square hole and filled with 1/2 inch aggregate. The vent emptied in there and then would be dispersed into the earth. Was easy to do when they was doing the yard drainage. May be hard to do if you decide to do it and have no reason. Plus I went and purchased 4 IR illuminators and some IR security cameras. After it was all installed NightVision and Ir cameras are useless as the whole area is awash in IR light. I got the idea after the company installed my home alarm system had installed the IR illuminator and IR cameras at the doors. Plus I live next to the presiding Judge.

That's hilarious! You've got balls!

I'm wondering if heat and IR would be a problem with a grow tent... Say I have a grow tent in a closet in my apartment and the exhaust is sucked through a carbon filter (smell is not a factor here) and is blown out the back directly into my closet.

Should I be moving air from my closet to a window with a house and window fan?
Would there be any heat or IR worries? or would the heat disperse by the time it reached my window with this method?
If this method is an inappropriate application, what would be more suitable?

Thanks for reading.
 
If your tent is in your closet and you're venting it into the (same) closet, wouldn't you just be moving the heated air in a circle (adding more heat each time)?
 
Well hot air rises and I plan on having the closet open to circulate using the entire room... but I would like to draw air from a window as well as exhaust out a window (possibly the same window unless the room has 2). In this case (exhausting from the closet to the window) I'm wondering if the heat would dissipate by the time it reaches the window, if not what can I do about the heat signature?
 
I have a sliding window so im kinda in the same boat as u agile. I been looking into an ice box but thats about a 1000 solution that i will possibly be able to afford in the future. I have a closet thats 8X6 and the room is 11X16 was thinkin of puttin grow tent in closet and just vent hot air into the room and leave the room open so air can circulate.

Finally, someone on the same page as me. haha

I'm thinking if the air were circulated around the room before exhausting out the window it would be okay. I suppose the best way to determine the temperature of your exhaust (from the window) would be to gauge it with a thermometer. Does anyone know what the temperature would have to be to be viewed as suspicious by IR?

This thought just came to me: How about A/C that faces outside instead of inside? You would pump out cold air instead of hot. Just a thought. I think I'll be doing a lot of tests with temperature, humidity, and circulation before starting a grow. Conditions will be fine tuned and perfected before I decide to raise some seedlings into some delicious bud. Thanks for reading. Peace.
 
Does anyone know what the temperature would have to be to be viewed as suspicious by IR?

General statement: Noticeably warmer than the other areas. IOW, a high temperature coming out of a fan in an upstairs window would be less noticeable than a somewhat cooler temperature in the Winter. Not to mention that an open window with a fan (or even just an open window) is kind of suspicious when it's snowing anyway, lol.

UNLESS, that is, you have a kerosene heater parked by the window. In that case, you open a window to keep from being asphyxiated. And so that everything in the room doesn't reek of kerosene fumes (it doesn't really help that; it doesn't do much to keep the airborne crap coming from the heater from degrading your electronics, either).

I'm not saying that a kerosene heater inside, exhausting hot stinky fumes through an open window, coupled with a five-gallon kero tank and hand-pump on the front porch would make a workable blind.

I'm not saying...
 
I'd be more likely to take the Summer off, lol. With a sealed reflector and using air to cool it that does NOT come from the grow room, in the Winter you don't have hot air to get rid of, you've got "free" supplemental heat for your home. Win/win.
 
A decent sized home theater with plasma TV , 5.1 surround and Media/gaming PC puts out more heat than the average closet grow.
 
I'd be more likely to take the Summer off, lol. With a sealed reflector and using air to cool it that does NOT come from the grow room, in the Winter you don't have hot air to get rid of, you've got "free" supplemental heat for your home. Win/win.

Good point, what about intake? Would that be warmer than if you were venting to the outdoors?
 
All the information you will ever need is from an ex-Drug Enforcement Agent for 17+ years by the name of Barry Cooper that is extremely knowledgeable in this subject matter. Here is his official website.

NeverGetBusted
 
Infrared cameras are widely used by law enforcement for border patrol, grow room confirmation, and other surveillance operations. There is legal debate as to whether this technology is intrusive or non-invasive.

Growers fear IR because it?s difficult to ?hide? invisible heat. Protecting yourself against excessive heat emissions is a good defensive measure. This FAQ focuses on masking heat emissions.

What is infrared?
Light and heat energy warm objects, which then re-radiate excess energy. Some of this excess energy is emitted as low-energy infrared. IR is invisible to the naked eye, but can be displayed and measured by specialized cameras.


What does Leo look for?
Officers are trained to look for hot spots on walls and windows, unusually warm foundations, exhaust emissions from vents and chimneys, and warming trends typical of marijuana grow operations. Leo will wait until evening or early morning (when the grow is up to full temperature and the air is cool). He will also look for light leaks, smells and other info at this time.

Note: Leo will try to image a suspected grow-op from all angles, but is only legally able to do so from public property (ie. Sidewalks, roads, public paths, etc).

Noteower companies occasionally image power pole transformers to see if they are abnormally hot (problems), and to source power theft.

Legal implications
(ExpensiveCloset) "A thermal imaging scan does not intrude in any way into the privacy and sanctity of a home?the privacy associated with a home, are (not) threatened by thermal imagery." (US supreme court ruling)

"The Supreme Court ruled 5 to 4 on June 11 [2001] that police cannot use infrared heat-detecting technology to gather evidence from a private home without a search warrant" High Times, October 2001 (Pg.20)

In Canada, IR is used in the pre-investigation phase. Positive results can then be used to obtain a search warrant.

Will Insulation help?
Conventional insulation will help block IR, but it is probably not enough by itself. A fully insulated wall (R 40) will hold heat much longer than a window (R 2). Concrete is a good conductor of heat; after hours of HID lighting, foundations will become abnormally warm.

Most growers flower at night to take advantage of the naturally cooler air; unfortunately, a warm grow house will radiate lots of thermal energy compared to the cool night air.

How do I mask my heat emissions?
Note: Small grows (under 2000w) would probably not emit enough heat to warrant the effort or expense.

Note: Reducing grow room temperature will reduce heat emissions; however, the grow room will still be warmer than surrounding basement rooms.

This technique creates a false wall to contain cold air. Interlocking rigid foam panels prevent hot grow room air from contacting and warming house walls. Cold air is blown into the gap between the foam and the walls for maximum protection. The wall?s exterior will appear ?cold? to an IR camera, indicating a negative for internal heat.

· "Partial room" (insulate exposed walls only)
· "Room in a room" (entire rooms are insulated)

*Floor. Concrete foundations absorb heat readily. Build a sub floor to raise the entire grow off the floor.

*Walls. Use interlocking 1.5 or 2? foam insulation along all exposed walls. Place the insulation 1-4? away from walls, fit foam panels from floor to ceiling (some cutting may be required), and blow cold air into the gap. Seal seams and corners with tape. Cover walls with Mylar to reflect heat back into the room.

*Windows. Windows are essentially uninsulated, so you must fill the gap with insulation. Draw the curtains/blinds, add black poly behind, then add insulation.


Drawing descriptionpartial
A ? Public property that Leo can image from

B ? Internal basement room. Grow room heat will still be noticeable, and this side needs protection.

C -- ?Safe? basement rooms. Put ballasts and reservoir outside to minimize heat

D ? Partially insulated growroom. The pink band is the interlocking foam insulation, the blue band is the cold air contained between the insulation and the house walls. The window on the bottom of the picture can be open to allow cold air to enter the air gap. Room temperature air can also be blown in from an adjacent basement room through a hole in the foam panels.

Hiding the Exhaust
Safely exhausting hot air is difficult; Leo looks for unusual heat emissions coming from opened windows, chimneys, dryer vents and other handy places. Note: running exhaust to outside sheds, barns and tree stumps is well known to Leo.


Every house has a sewer vent standpipe. By venting down the sewer, the exhaust will be chilled and smell is distributed amongst you and your neighbors. The sewer cleanout access is often a 3-way 4? abs ?T? with a threaded cap somewhere in the basement. Remove cap, and hook your blower to the T (A 4? to 3? adapter funnel may be required) and run blower 24/7. This will not affect normal use of the sewer

Cool exhaust with water
Place a wet towel (wicking water from a tray underneath) partially over the end of the exhaust. Spraying water inside the exhaust pipe works as well.

Underground exhaust
Running the exhaust through a long, buried pipe helps to cool the air. Perimeter drains can be used for this.

Water-cooled lights
Running water cooled lights is very effective; IR heat from the lights are washed down the drain. Water cooled light systems are currently difficult to source, and have drawbacks including cost, condensation and leaks.

Tools for the grower:
Note: most ?night vision? devices use UV (ultraviolet) and not longwave IR detection.

Engine heat ?guns?. +/- 1F. Numerical readout, laser pointer.
"Night Vision" scopes, cameras and camcorders.
Infrared film (Kodak High Speed Infrared Film 2481)

Yes law enforcement do use such devices. Heres the thruth. To use such devices it costs a lot of money. So, if no ones that you have a small grow in your house than no one is going to look. If you keep your mouth shut, grow for yourself, I feel that you'll be ok.
 
Has anyone used IR-blocker? I don't think it would help with exhaust though.

EIS Optics UV/IR-Blocker effectively remove damaging ultraviolet and unwanted infrared radiation produced by broadband light sources. A dielectric oxide coating design provides excellent transmission over the entire visible spectrum, without distorting the spectral emission of the light source. Filters are optimized for metal halide lamps and are particularly well suited for use in applications where high thermal loads exist. Where infrared radiation is not critical use the EIS Optics UV-Blocker.
 
i got a pir attached to light iff light comes on too much heat from exhaust i then got fan that blows cooler air into garage hence cooling air emitted
 
Out in the sticks we use a couple of methods. First totally sealed pole barns with a separate electric meter. This means that when your bill comes it clearly says "barn" on it. Farmers commonly use heat lamps and other devices to keep animals warm. But the biggest thing that I have helped people with is in using low cost non-functioning coolers. There are alot of these on the market because so many restaurant and store are out of business. They are perfect! You can get them from 4x4 up to gargantuan. 12x10 and 10x10 are commonly used. Here is the best part they are 8 to 9 feet high and most have lockabe latches on the doors. I'm not saying they are foolproof but they sure have to help and i know they are like miniature factories!
 
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