I’m wondering how to increase the humidity in my home. I have a venmar constructo HRV system and have looked at the manual and many videos and can’t find the answer. I’d like my humidity to be 35% for winter as we have triple pane windows. It seems that no matter where I set the dial, it never gets higher than 32% and seems to fluctuate between 30-32% regardless of the setting. Does this mean that my newer 2015 system is broken already or is something else going on? I’ve had the dial set between -4F to 23F and even higher and the actual humidity doesn’t seem to change. Right now the outdoor temp is around 23F (-5C) so I’m worried that it’s only going to become dryer as it gets colder. Any thoughts/ideas to help me please?

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    Hello, and welcome to Home Improvement. The Venmar is an air-to-air exchanger; do you have a humidifier? Dec 4, 2018 at 11:37
  • I thought it was a heat recovery system , unless it has an internal humidifier I agree with Daniel. If it has a humidifier it is probably plugged up they require more maintenance than most folks realize.
    – Ed Beal
    Dec 4, 2018 at 23:36

1 Answer 1


You cannot actively increase humidity with an HRV, at least during the cold months. The dial control allows you to run the unit as needed to reduce humidity by exchanging more moist indoor air with dry outdoor air. If you'd like to raise humidity you need to actually introduce moisture into your home.

A standalone humidifier in an appropriate location has done well for me in the past if you wish to avoid the expense of a whole-house unit. Place it where the air movement won't create discomfort and where the HVAC system will help circulate and distribute moisture.

By the way, you should not settle on a fixed RH for the entire winter season. You want to vary it depending on the outdoor temperature to avoid excessive moisture buildup and to prevent discomfort. 35% is quite low if it's 50 degrees F. outside, and may be high if it's -30F.

  • Outdoor temperature over 50˚F, indoor humidity levels shouldn’t exceed 50%
  • Outdoor temperature over 20˚F, indoor humidity levels shouldn’t exceed 40%
  • Outdoor temperature between 10˚F and 20˚F, indoor humidity levels shouldn’t exceed 35%
  • Outdoor temperature between 0˚F and 10˚F, indoor humidity levels shouldn’t exceed 30%
  • Outdoor temperature between -10˚F and 0˚F, indoor humidity levels shouldn’t exceed 25%
  • Outdoor temperature between -20˚F and -10˚F, indoor humidity levels shouldn’t exceed 20%
  • Outdoor temperature at -20˚F or lower, indoor humidity levels shouldn’t exceed 15%


  • I like portables for several reasons but the first is easier to clean and a malfunction won't flood the duct work if central air/ heat. I did not realize at the much colder levels the humidity needed to be lowered that much but where I am it rarely gets in to the nasty minus territory. +
    – Ed Beal
    Dec 4, 2018 at 23:33
  • Thank you, very helpful! I’ll invest in a portable humidifier!
    – user93835
    Dec 4, 2018 at 23:58
  • You're welcome. Please take the tour to be sure you know what's expected of you when you ask a question.
    – isherwood
    Dec 5, 2018 at 13:36

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