Cabinet Ventilation

[jstockman]

Guys,

I am building and entertainment center with upper library shelves.  In the center of the base will be my surround sound prologic receiver, DVD etc.  I am concerned about ventilation.  I am using melimine with finished stiles and rails for base and paint grade birch ply for uppers.

I was planning on using MDF doors.  Any suggestions on best way to get air to the base that holds the electronic components.  I was hope to find some MDF doors that had some sort of ventilation in them.

Thanks for any advice.

jstockman

 

[Kevcoleman]

something like this would work
Home Theater Cooling Fan or thiscooling fan at amazon
I built an AV cabinet and didn't put a fan in.  I had an AV receiver and an old Pentium 5 HT PC in it.  When I first set it up, I turned everything on and closed the doors and left for about 30 minutes. When I came back, the fan in the PC was squealing very loud and the cabinet was practically on fire it was so hot in the cabinet.  So you will definitely need a fan or two.  If its going to be in the same room as your TV definitely consider the sound level of the fan and use a thermostat so it comes on automatically.  The link i gave you is for a 120 volt version so you don't have to have a transformer.  A lot of the fans you will find are 12 volt so you need a transformer.  

 

[mhoy]

I use a radio shack 5" fan blowing air out the back of the cabinet. It runs all the time at a low rate (9 DC v feeding a 12v fan). Works well enough. My DirecTv box never 'really' shuts off so I run this all the time. The make up air comes from the edges of the door which don't fit perfectly flush.

Another possibility would be an air intake on the bottom of your cabinet with the exhaust from the upper area. I also have large holes for cabling (which I had used a 3" hole saw instead of a 2" one).

I use a smart remote control that uses radio freq to relay commands to a receiver inside the cabinet that then sends IR pulses to numerous IR emitters taped to the inside of the doors.

Mark

 

[slb]

When I built an entertainment center a couple of years ago I got a lot of advice from the high-end store where the customer bought the gear.  They told me that you ignore heat at great peril to the equipment.  They get a lot of repair calls that turn out to be due to overheating.  So, you are smart to be worrying about this.

They said that the three key factors are:
1) having a way for hot air to get out of the cabinet effectively (very often need fans)
2) having a large enough opening down low so that adequate fresh air can get in (needs a lot more area than just the crack around the doors)
3) making slots through the middle of the bottom and any shelves so that the air doesn't all just go up the edges

Of course, if you only run the equipment with the doors open, air intake isn't a problem.  You just have to do something to let hot air out the top of the back.  But if you leave things on while the doors are closed, especially if you get a radio or IR repeater for remotes so that you don't even open the doors while you run the equipment, you need to take better precautions against heat.

If the unit stands on legs, it's easy to make inconspicuous openings through the bottom.  If you have a face frame and a toe kick space, one easy way to make an air intake is to leave a gap at the top of the toe kick board behind the face frame rail (that's what I did).  Louvered doors are a possibility, though I doubt the slats could be MDF - too weak when that thin.  Failing these, you pretty much have to make an intake hole somewhere visible, and the main challenge is to keep it from being too ugly.  I saw one cabinet that covered an opening with speaker grille cloth.  Another had some kind of coarse mesh stuff, sort of like filter media.

Hope this helps.

Steve

 

[GreenGA]

I designed a couple of entertainment cabinets for a woodworking friend and what I suggested, and has turned out to be quite effective, is the following.

Along inside back top of the cabinet with the heat-generating equipment, place a series of one-inch holes drilled at the very top.  A few inches in front of these holes, install a panel (1/2 inch plywood ?), either colored black, to disappear or match it to the interior color.  This panel is installed at the top and drops down in front of the holes, kinda like a curtain.  It should be long (high/tall) enough that the holes are not visible from the front.

In the bottom of the cabinet, under the equipment, drill another series of holes, which will allow air to enter from outside the cabinet.

The heated air will rise up inside the cabinet, exiting through the holes at the top and this heated air will be replaced by the cooler air entering from the bottom.

I have a very large entertainment cabinet which implements this method of cooling and I can leave the bottom doors closed and the equipment remains cool; well, at least cool enough to not cause a concern with overheating.  In this section of the cabinet, I have four heat generating factories. 

The best way to describe the effect is to think about those images of fire one sees on televisions or in the movies.  You know?, those scenes where the fire is ?crawling? along the ceiling of the room in waves.  The heat inside the cabinet behaves much the same way.  The holes drilled in the top of the cabinet allow the heated air to escape.  The panel hides the holes from view and the holes at the bottom allow the air into the cabinet to replace the escaping, now heated, air.

Think about it.

If I may offer another suggestion...

If you would like to hide the equipment, but still need to operate it remotely, consider placing an IR pickup in a ?rail or stile? frame member then run the lead wire of the pickup towards the interior and then split off the pickup signal and feed leads to all your equipment.

If you go this far, consider placing a surge protector inside the cabinet along with some A/V ?cables? that are easily accessible from the rear.

 

[Jay Knoll]

What is on the other side of the wall which abbuts to the base cabinet where all the components will live?  If it is an inside wall, and the other side is inconspicious, then you might consider cutting through the dry wall and putting in a couple of air return grates so you'll have plenty of air moving though that area.

I did this when we remodeled our kitchen and the fridge was "built in" with an end panel and cabinet above it.  Lots of good air flow and now problems with the unit.

Jay

 

[peter halle]

My cabinet was designed to work with convection - holes in bottom as well as at top.  I also have an 4" fan inside to circulate the air inside.  It has an integral thermostat that varies the speed of the fan based on temp.  Very quiet too.  Usually used with aquariums.

Peter

 

[GPowers]

It has an integral thermostat that varies the speed of the fan based on temp.  Very quiet too. 

Peter

sounds like a cool fan where did you get it?

 

[peter halle]

I will get you some links.  There are name brands and then some knock offs that are excellent quality.

Peter

 

[GPowers]

Thanks, I found some but when it comes to being quire I would rather get a reference for some one. Instead of just picking one off the net.

 

[peter halle]

Go for the CoralVue fans.  You can't hear them.  One half to two thirds of the cost of the "industry standard".

I checked mine just before posting.  I breathed on the thermo resister to increase the temperature and was rewarded by an increase in RPMS.  That unit is over two years old.

Do a google search for CoralVue fans.  Figure out your cabinet size and then go from there.

Peter

 

[GPowers]

Thanks found several links, lowers price around $29.99.

 

[jstockman]

What is on the other side of the wall which abbuts to the base cabinet where all the components will live?  If it is an inside wall, and the other side is inconspicious, then you might consider cutting through the dry wall and putting in a couple of air return grates so you'll have plenty of air moving though that area.

I did this when we remodeled our kitchen and the fridge was "built in" with an end panel and cabinet above it.  Lots of good air flow and now problems with the unit.

Jay

Jay,

It is an inside wall.  The other side is our utility room.

Jim

 

[J.C.]

Another good place for cabinet ventilation stuff is www.coolcomponents.com  I bought a few of there things a couple years ago for my entertainment center and so far so good. 

 

[westom]

.  Any suggestions on best way to get air to the base that holds the electronic components.

 Any fan that just blows air around inside the cabinet is wasted energy - adds more heat to the cabinet.  Your fan must be either blowing out or in.  Makes no difference which direction.  As long as air moves across the cabinet.  Massive cooling is traditionally air moving so slow that you cannot feel it.

 Your concern is two numbers.  CFM and dBs.  The first is the amount of air moved per minute.  That determines the delta temperature difference between outside and inside temperatures.  For example, one 60 mm fan in a computer means 250 watts cause but a few degrees temperature difference inside and outside the chassis.  dB is the amount of noise.  Generally (but not always) a larger fan moving same CFM is quieter.  The better (more reliable) fans tend to provide these numbers.  Cheap fans do not.

 Dust is determined by CFM.  Those who foolishly install too many fans (more too much CFM) are constantly cleaning dust.  Your CFMs should be low enough that dust need not be removed for many years.

 Obviously, nobody can answer your fan question without numbers.   First determine wattage (heat) inside that cabinet.

 

[jstockman]

These are all great ideas.  Obviously most entertainment centers need air circultion.

What about cutting slotvents about 8 inches long about 1/2 wide in the melamine bottom and and top board.  If I go this route what woud be the best way to cut them so they look good?  Any thoughts?

Also,  what is the best way to cut out the electrical outlets and the low voltage gang boxes for the various wires that are needed for surround sound?  I can see two problems for me.  1.  Chipping the melamine and 2 not lining up the cuts to the junction boxes.

Is there a simple way to do this.

I can't thank you guys enough for you help.

Jim

 

[peter halle]

Do you have  a Festool router, a guide rail, and the necessary attachment?  If so, it is easy if you set up stops at both ends.

 

[jstockman]

I have a festool ts55 and MFT3, two 55 inch guide rails, and  a Black and Decker router that a friend did not need.  If I set up some sort of jig to keep the router on track, what kind of router bit will do the trick?

Jim

 

[harry_]

1/4" mortising/dado bit

 

[MarkF]

I use a solid Carbide spiral down cutting bit to get the cleanest cuts on Melamine.  You can use a hole saw for cable passages and dress it with a grommet.

Check:
http://cableorganizer.com/grommets/  The lip on the bigger grommets will cover any chipping.

If they don't have what you need you can probably do without it.