How to: add simple, inexpensive feet to your electronics tower for improved passive ventilation

I’ve often wondered if there was an easier way to improve the ventilation of the consumer electronics in our family room entertainment system.  We have a couple of pieces in a cabinet under our family room television (tuner, Replay TV DVR, DVD recorder, Xbox 360 and other equipment).  Often with these devices, manufacturers often recommend that units be no closer than an inch from another piece of electronic gear to provide adequate ventilation.  In fact, our DVR has an added whisper fan unit I installed to help cool the PCB and hard drive, and needs some clearance to operate efficiently.

I thought apart from building bulky shelves or adding noisy cooling, there must be an inexpensive way to provide acceptable passive cooling.

I originally thought to purchase a small shelving unit (glass or metal) that would support the gear as well as fit nicely within the AV cabinet.  But I wanted to reduce the amount of stuff in the cabinet as it seems we’re often putting new stuff in, adding a cable or making new connections. 

I remember various systems that audiophile friends have installed to rack and support their direct-drive analogue turntables, which I’ve seen suspended in mid air, levitated and dampened to reduce the chance of a needle skip on the classic copy of Einstein on the Beach.  I’ve seen that audiophiles often rely on isolation feet (some are $10-20 a foot, and can run into the $100s as noted here).  These are shaped like cones, squares and hockey pucks, often constructed out of different materials, providing not only elevation absorbing the shock of a knock to the cabinet or walking across the floor. Some are quite attractive as the one at left, the Tara Labs Vanishing Points, and is easily added to a system.

But, I’m not looking for complete turntable vibration isolation.  I’d like the air to circulate around the gear and decrease the close proximity of to pieces of gear that could be hot enough to fry an egg.  Well, not really, but you get the idea.  High tech components being what they are, heat is on of those things that can contribute to a drop in the life span of a favourite piece of gear.  We also have a lot of gear, so the cost for the Vanishing Points (although quite lovely and will have a place in our home theatre one day) is higher than I’d like to spend on the gear in the family room and the kid’s play room. 

Last fall, I was working on my son’s Halloween costume, walking through Lowe’s Hardware with my six year old son. We were looking for pieces to make a light sabre thingamajig for his older brother’s red imperial guard costume, and we stumbled upon a solution.

PVC pipe caps.

The Lasco branded 1 1/2 inch PVC Cap to be specific works quite nicely, either cupped/ slipped over the feet of many CE devices, or (upside down) permanently mounted to the bottom in place of existing feet. Available at many hardware stores (and certainly available from different manufacturers), these are inexpensive pieces that probably will find more uses than the one I’ve outlined here.  

Permanent mounting takes a little longer as there is drilling involved, and a possible trip to the hardware store to get the right hardware that’s sometimes needed (see below).

For items in our home, I first dry run the fitting by placing the cap over the existing feet upside down (as pictured at left), allowing me to verify the fit and placement.  You can use a dab of hot glue melt to hold them in place, but gravity works fine for smaller stack of one to two units. 

Prior to use, these caps can be spray painted to match your consumer electronic system with just the right paint (I have successfully used Krylon Fusion spray paint for plastics on past PVC projects for the kids) or left industrial white.

I find that the 1-1/2″ is fine for retrofit replacement feet. Just unscrew the existing foot from your electronics, drill a hole in the centre of the top of the closed end of the cap and reattach the cap in place of the foot. You could use grade school geometry to find the center of a circle, or you can eyeball it with these caps, as the raised logo has a nice little rectangle directly over the middle of the cap’s top. 

Most existing screws will accommodate the thickness of the PVC cap… if not, take the screw in to Lowe’s and they’ll most likely be able to find hardware that fits the bill.  

For permanent feet, you may also add adhesive felt or rubber cut to the shape of the cap, if you’re concerned about marring the tops of your gear.  I found no scratching or blemishes as a result of the caps, but your mileage may vary depending upon the composition of the case of your electronics.  For an industrial sprayed metal chassis, so far no effects have been seen.

All up, the cost for the four caps was under $3 as I was able to use the existing screws.

If you are fitting the caps over a electronic device that has the now popular adhesive mounted rubber feet, use the cupping approach and lightly glue them into place.  You could also use them as a makeshift isolation foot by setting them in between your electronics and place a small, inexpensive adhesive rubber foot (also available in hardware stores and at Radio Shack) on the top of the cap.

Lasco Fittings makes several different diameters — from half inch all the way up to eight inches — just measure the diameter of the feet on your electronics to find the right fit for a slip-cover approach. Then do an advanced search in the Schedule 40 product category for “cap.”  Lowe’s seems to carry a selection of diameters up to two inches.

Tags: How to, DIY, hardware.

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