I have an old house which has been updated but it doesn't have great ventilation in the finished basement and often smells a bit musty and damp

There are no leaks and the drainage system has recently been updated

I have used a dehumidifier and that helped

I have considered getting a hunidex system Or putting in an hvac but that would mean holes and ducts and dust

Then I renembered we have a built in vacuum which had openings on every floor and which we never use

How about taking the central vacuum out and just replacing it with a system to gently suck out air which I could then pump out through a pipe out if the house

Does that make sense ? Does such a device exist ?

Thanks +++ for any advice

  • I have long wished for a central vacuum system in our 50 yo house, but retrofitting is so far down on my list that I will never get to it. If you ever put your house up for sale, I think a central vac would be a selling point. But maybe I don't realize the limitations of these systems. Why don't you use yours? Do you prefer a broom and dustpan, a canister vac, a cordless vac, a damp mop, . . . ? Jun 24, 2018 at 9:35
  • 1
    @JimStewart most people that don’t use their central vacs don’t because they have trouble managing the 30 foot hose, especially those with multi-story houses that don’t have a hose and accessories for each level. We bought a foreclosure 5 years ago that has a central vac, it has more power, doesn’t recirculate dust etc. Being a foreclosure the tools/accessories were long gone, after buying first set we quickly bought a second set, we also noticed the inlets on one level of the house had zero signs of wear.
    – Tyson
    Jun 24, 2018 at 11:52
  • How many connections are there on each story? I presume that the sound level is much lower than a basic canister vac so one could listen to the TV or radio while vacuuming, right? Jun 24, 2018 at 15:07
  • Darren, as a test, if you have a hose, plug it in the basement and let it run for 24 hrs and see if this, reduces the musty smell. More likely you would need a pair of ducts between the basement and the floor above to circulate air. One the ducts would have a fan on it pulling air into the basement from the floor above. Another possibility would be to adjust the restrictors in the duct system to direct more central HVAC into the basement. If you did that then maybe all that would be required would be a vent in the door leading to the basement. Jun 24, 2018 at 15:19
  • If air exchange doesn't eliminate the musty smell, then that might indicate that the musty smell is coming through the walls of the finished basement. Jun 24, 2018 at 15:21

3 Answers 3


Taking air out of the house like that would mean getting more fresh air into the house. A little would be good. A lot could result in drafts in strange places as the air would come in from wherever it can. The effect would likely be uneven as some areas, perhaps with leaky doors/windows, would get a lot of fresh air and others would get almost none.

In addition, the air coming in would be as hot/cold and humid as the outside. That would help feel less musty but not necessarily less damp or feel "good".

A quick search finds that central vacuum typically uses 2" ductwork where HVAC typically 6" or larger. That being said, perhaps an inventive HVAC tech. could come up with a solution to use the central vacuum ductwork for an HVAC system. Or possibly a mixture - use traditional HVAC ductwork for the easiest runs (and/or the rooms that need it the most, like the kitchen) and use the central vacuum ductwork for the rest.


I wouldn’t see why you couldn’t, the duct diameter doesn’t mean it can’t work, it would just diminish your cubic feet intake. I’m not certain the capabilities of the system but if you have suction from all rooms at once and the esc/vacuum device is expelling air and intaking air from outside. If no external air it would be like vacuuming inside a closet If you’re expelling the air outside through something like a dryer vent to the window or even an old dryer vent, but if your vacuum’s intake module is inside it’s gonna create drafts. Ex:blow up mattresses with integrated pumps, when it gets to that point when the pump starts making a higher pitch as it’s sucking the air out. If you open all of the valves or switches for each room that has a hose hookup, turn the vacuum on, open a window in each room with a hose hookup that you opened the switch at. If the room where the esc is located is inside, close the valve for that room if it has one (not the hook up from the whole house) and open a window an set a fan in front of the window facing inside the room to draw air in. Should be able to determine flow. Windows do not have to be opened much, the more flow, the more open you make it.


You can use a bathroom exhaust fan to blow air into ducting but there should be a fresh air intake to be effective.

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