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Central vac venting and heat recovery units

user-885167 | Posted in Mechanicals on

If one is willing to have a central vac’s filter/cartridge inside the thermal envelope, can the down stream “dirty” air be vented through a heat recovery unit, without messing up the HRU too badly or causing some other problem?

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  1. Trevor_Lambert | | #1

    This raises two concerns in my mind. The first is how much air is the central vac moving? If it's in the same order of magnitude of the HRU, you're going to have balancing problems and potentially depressurize your house. If it was say 10% of the HRU flow rate, it probably wouldn't be a big deal. I can't see that being the case, however.

    The second is the "dirty" air, that the HRU filter would then have to handle. This is probably of not much concern, assuming the vac's filter is decent.

    Why not just re-circulate the central vac air? I would have thought that was the standard practice.

  2. GBA Editor
    Martin Holladay | | #2

    Q. "Can the downstream dirty air from a central vacuum cleaner be vented through a heat recovery unit?"

    A. No. Call up the manufacturer of the HRV if you don't believe me.

  3. Expert Member

    I thought one of the main benefits of central-vacs were that they exhausted outside the house, rather than recirculate fine particulates?

    1. NormanWB | | #4

      I agree with Malcolm: vent it outside. If depressurization is an issue, crack a door or window while vacuuming.

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