Central vac installation questions.

November 26, 2012 8:19 AM

Questions about installing the tubes for central vac.

We have some walls open in our house and I'm taking the opportunity to pull some wires, etc. to support potential future upgrades. I want to put in the tubes for central vac, so that the next time the vacuum cleaner needs replacing, opting for central vac is (almost) as easy as installing the unit.

I've looked up manufacturers' installation instructions and have some questions.

1) They say not to install the vacuum unit in the same room as the furnace. How important is this? We have sort of an odd-shaped house and installing the vac unit anywhere else would be reducing the living space, which would probably mean I won't bother. Are there precautions I can take which resolve in another way the issue being addressed by this recommendation? Our furnace room does not get very hot, for what it's worth.

2) The recommendations for installing the tubing recommend one vertical tube near the central unit with tubing running horizontally along each level of the house. Because it is walls that I have open, it would be simplest for me to run one horizontal tube in the basement ceiling and then several vertical tubes that have outlets on each level. Is there a reason this would affect the performance of the system?

posted by winston to Home & Garden (5 answers total)

Best answer: No clue on #1. But for #2, I would imagine that it is because the horizontal trunk line would tend to collect dust, where a vertical one would let gravity assist in getting the dust down to the collector.
posted by gjc at 8:38 AM on November 26, 2012

Best answer: Re #1: Combustion furnaces are designed based on certain assumptions like amount of available fresh air. I'm guessing that the central vac unit may muck with these assumptions.

You don't want to mess about with fire and harmful gases. I'd heed this requirement carefully.
posted by humboldt32 at 9:46 AM on November 26, 2012 [2 favorites]

Best answer: Given your constraints it sounds like central vac may not be for you. The unit would exhaust into the furnace room which I would think would not be ideal from a whole house health perspective. As for the vertical pipes rather than horizontal pipes, I presume its a matter of suction loss or performance but you may need to contact the company directly to get the air flow measurements or an installer. It is also possible that a different unit may have different venting needs that could work with a furnace installation. More research here could help.
posted by saradarlin at 2:04 PM on November 26, 2012

Best answer: For #1 - Our central vac is in the garage, right next to the furnace. Installed w/ the house, so circa 1990. Don't cause any problems w/ furnace. Do instructions specify room vs garage ?

It may be possible via a self-closing vent (think dryer vent hoods, or soffit vent covers) to pipe the vacuum's waste air outside, depending on your room/house layout.
posted by k5.user at 2:06 PM on November 26, 2012

Best answer: Maybe you should have a look at some other brands of central vaccuum. When I installed ours there was no warning about furnace rooms, it is designed to exhaust to outdoors much like a dryer or the furnace itself.

I also went with a layout similar to what you are suggesting (verticals to each level with horizontal runs to the central unit in the unfinished basement), haven't had any issues with it. My understanding is that it was more of a guideline to minimize the length of pipe to each outlet; if you have enough power in the central unit for the length of the runs then it will work either way.
posted by N-stoff at 2:19 PM on November 26, 2012