Heat build-up in a cabinet for video components

[David Thompson 27577]

I'll soon be building a cabinet that will house some video components -- a cable/satelite box, a DVR, a DVD player........

I'm assuming that I need to allow for some heat dissipation. I plan to use some saw-kerf slots near the bottom, and in the top. In addition, I'll back-cut the shelves so that both wires and air can have free passage/movement.

I'm worried that the slots might not be enough to dissipate heat. Do any of you have experience with such a problem? Am I overkilling the worry, of should I add plans to vent this cabinet through an outside wall, and include a powered fan with thermostat control?

[Van Huskey]

I'll soon be building a cabinet that will house some video components -- a cable/satelite box, a DVR, a DVD player........

I'm assuming that I need to allow for some heat dissipation. I plan to use some saw-kerf slots near the bottom, and in the top. In addition, I'll back-cut the shelves so that both wires and air can have free passage/movement.

I'm worried that the slots might not be enough to dissipate heat. Do any of you have experience with such a problem? Am I overkilling the worry, of should I add plans to vent this cabinet through an outside wall, and include a powered fan with thermostat control?

Of the components you list the DVR will probably produce the most heat, you shouldn't have any issues as long as the front is open and you are not stacking the components on each other. Where you run into the biggest problem is amplifiers and receivers.

[hank dekeyser]

david, you didnt mention if the cabinet was to have a glass door, open face, or ??? Assuming it will be open to air movement in the front, MOST times you will be OK. It will depend on how close the components are to the sides and back of cabinet, and in which "order" they are stacked. What I mean is, don't put the unit that produces the most heat on the bottom (put it on top) heat rises and in some cases the unit that doesnt produce much heat will not fare well on top of a hot unit. (If you only have a couple 3 components, dont sweat it, pile 'em up so they fit) I've been stacking components for many years as both an avid stereophile and a home theatre / stereo installer. I have never had an issue where a componnent failed due to excessive heat. I have had customers with "close calls" IE: most components have a thermal shut off inside that will power the unit OFF due to excessive heat. Use your head when stacking and you'll be fine. Personally I like to leave an inch on the sides and as much as possible in the back . Be sure to design the cabinet shelves with ai rmovement and cable routing in mind. I make my shelves at least an inch or two shorter than overall depth.

In short - for the average dvd, dvr, sat TV box, etc. installation you will be just fine with no neeed to add venting (if the front is open)

IF however you are adding a huge subwoofer amplifier or multi channel proccessor and amp, that is a different story. Most receivers / amps will be fine. Big subwoofer amplifiers likely will need a little help w/ cooling. It all depends on how you use the system (and how BIG the amp) Then again, the monsters usually have a fan built in to them.

[David Thompson 27577]

{Hank -- you said a bunch of stuff, then you said:}

In short - for the average dvd, dvr, sat TV box, etc. installation you will be just fine with no neeed to add venting (if the front is open)

IF however you are adding a huge subwoofer amplifier or multi channel proccessor and amp, that is a different story. Most receivers / amps will be fine. Big subwoofer amplifiers likely will need a little help w/ cooling. It all depends on how you use the system (and how BIG the amp) Then again, the monsters usually have a fan built in to them.

Thanks for the quick response.

The cabinet is to have a glass door on the front, and is to be installed -- screwed to the wall. There is no amplifier, no big speakers. Just the cable box, the DVR, and the DVD.

[Lee Schierer]

Years ago we did some testing on a surgical light to use convection air flow for cooling. What we found is that openings less than 1/4" x 1 we got little if any air flow. You can make some pretty large slots in the back of the cabinet and they will not show through the front with the components in the way. You are going to need a slot to get the wires out the back of the cabinet anyway. If the cabinet is to be tight to the wall then make the slot in the bottom and design in a gap across the top of the door in front.

Your amplifier will create the most heat followed by the DVR. Make sure you leave space between them. Any component with slots or openings in the case needs to have air flow to prevent overheating.

[Rod Sheridan]

Years ago we did some testing on a surgical light to use convection air flow for cooling. What we found is that openings less than 1/4" x 1 we got little if any air flow. You can make some pretty large slots in the back of the cabinet and they will not show through the front with the components in the way. You are going to need a slot to get the wires out the back of the cabinet anyway. If the cabinet is to be tight to the wall then make the slot in the bottom and design in a gap across the top of the door in front.

Your amplifier will create the most heat followed by the DVR. Make sure you leave space between them. Any component with slots or openings in the case needs to have air flow to prevent overheating.


My exact thoughts, very small openings will have no airflow.

When I made my audio cabinet I used a 12" X2" opening in the back door (at the top of course) and the same size opening in the front bottom to encourage air flow through the cabinet.

Regards, Rod.

[Floyd Mah]

Here's something to consider. http://www.silentpcreview.com/forums/viewtopic.php?f=8&t=2359 Read the link, but the basic concept was that Apple didn't want to use a noisy fan in their computers and instead designed the architecture of the case to promote airflow using convection cooling. Some Mac owners decided that that was insufficient and constructed chimneys which they placed on the top of their computers. The idea was that the physics of hot air movement would draw the interior air out of the case and bring cold air in from the bottom. The additional height of the auxiliary chimney would cause a greater volume of air to be pulled through the case, compared to the volume of the small chimney created by the case of the Mac. Anyway, I tried to put this into effect into use on a built-in cabinet in my family room once. I can't really say that this was totally effective since I did not take measurements, but since you are considering a de novo audio cabinet, it might be possible to conceal a hollow area in the interior or back of a cabinet that will draw air out using this effect. It would be completely free of noisy fans and might be esthetically cool as well as be physically cooling.

[Greg Portland]

The DVR is a computer and puts out quite a bit of heat. Also, you have no idea what components will be added to the cabinet in the future. I would bite the bullet and install some 4"-6" near-silent fans in the top of the cabinet to pull the hot air out.

[Peter Quinn]

I can't tell you what needs to be vented and what doesn't , but I can tell you my wife cooked the DVR that had all my David Marls' Woodworks recordings on it. Every episode, I keep meaning to save them to disk, all lost, and now its off the air. She stacked the DVR on top of the DVD player, all on top of the old cathode TV, cable guy declared it DOA! I cried a little that day, even though the DVR had insurance and cost us nothing to replace. No more woodworks!

Anyway, I helped a guy on a side job recently that involved a large media cabinet for a family room. It was a wall to wall unit with he AV component cabinets on each side, one side to house amplifiers for a whole house sound system and the other handling DVD, TV, movie projector controls, ect. Both were vented. The designer, with the AV company, had designed a cabinet with an open "toe kick" that drew air up and in through a gap between the toe kick and FF. It formed basically a 3" X width of cabinet interior air intake. Hot air was pulled out with a small fan to be added on installation. One side vented to the side near the cabinets top, the other up the back and out through a grill built into the back of the top made of wood with punched out aluminum beneath. I didn't see them installed, just helped making the unit in the shop, but it looked like it would be pretty much invisible, and wasn't much trouble to accommodate. The shelves had gaps to the backs for air flow, each device was to have its own shelf, all shelves were adjustable, some of the shelves at the top and bottom were pull outs on slides IIR. Seems it wouldn't be hard to build a basic venting scheme into the cabinet to allow convection cooling, or at least allow the hot air to rise out, and perhaps decide later if power venting seemed necessary. You could throw a thermometer in there to check the ambient temp during operation.

[Van Huskey]

This really should be rather simple. First, I HATE active cooling with sound equipment first I can usually hear them and they can fail. I will not buy an amp or receiver with a fan, if you are too cheap to build your amp section without a proper heat sink then I will go somewhere else Mr. Manufacturer!

Like I said given the components you have the DVR is the critical one. Plan a shelf for it at the top, leave an inch or so minimum on the ides and 2.5-3 inches free space on top, then leave the back of that shelf COMPLETELY open. In normal situations, especially with glass on the front, it won't be visible. My current den setup is completely open behind the components and it just looks like a black hole behind them, no different than if it had a back.

No fan to clean, fail or hear.