Tonight I was trying to find out what dehumidifiers might be more energy efficient. (Any suggestions?) I came across a Canadian product called a "HumiVent-2000," www.onlinehere.com/humidex, which sells for $475 and is supposed to work by venting cool, humid air from the basement floor, allowing that air to be replaced with warmer, dryer air from the floor(s) above the basement. It's supposed to work better than a dehumidifier and cost much less to run.

Has anybody heard of the HumiVent-2000? Does it work? Is it a rip-off like magnetic water softeners?

 

The Humivent 2000 air exhaust system pulls warm, humid air down into the basement and exhausts the air outside the home through a wall in the side of the structure. The idea of not having to empty a dehumidifier or run a drain line for it is appealing. The theory behind this is to equalize the high pressure area upstairs with the low pressure area downstairs.

You should first address the source of the dampness and humidity in your basement before making an investment and cutting a hole in your wall. Yes, warm, humid air tends to settle into the cool basement because it migrates to an area of lower pressure. Warm, humid air tends to condense on cooler surfaces just like it does on the outside of your glass of ice tea. This problem however tends not to be the major source(s) of moisture in basements, but it can be a problem. http://www.concretenetwork.com/concr...reproblems.htm

There are many other sources of basement moisture and other issues that need to be addressed before investing in an air exhaust system.

http://www.extension.umn.edu/distrib...s/7051-04.html

Ventilating with warm, moist air in basements, especially during the summer, tends not to be recommended. I found no research or testimonials regarding the Humivent other than the info on their website where they touted the effectiveness of their product.

I recommend that you contact a forum member, F. R. Lazaro, at http://www.resercon.com/ who is an expert on ventilation, moisture, thermal boundaries and insulation in homes. His scientific and construction expertise has proved to be invaluable on the forums. I have learned a lot from this gentleman, and I look forward to hearing his professional opinion.

 

If there is a humidity problem in the basement, then treating the problem without addressing the source of the problem will not resolve your problem as twelvepole so aptly pointed out.

When it comes to product claims, in most instances the language used is there to deliberately confuse you. Many of the finding these manufacturers used in products similar to this one is partially conditioned spaces. There is no such thing, which they try so hard to rationalize. There are only conditioned or unconditioned spaces in a structure. You either heat and/or cool that space or you don't. Having a water heater, heating system and/or ducts/pipes in that space does not partially condition the space. That would imply we want our heating and cooling dollars to be spent in those areas.

This product uses the neutral pressure zone as the basis for their product. This topic is highly subjective, in fact I refrain from discussing it with experts on this subject because of it. The manufacturer assumes the basement is conditioned and rationalizes partially conditioned basement for their product applications.

If you don't deliberately heat or cool your basement, it is illogical to use conditioned air to balance the humidity problem in the basement.

If you do have a conditioned basement, any attempt to improve humidity in both spaces through forced ventilation between the 2 is highly unlikely. Equilibrium Relative Humidity (ErH%) does not only apply to air but also to materials. twelvepole's link concerning concrete and moisture illuminates this. There is a difference between rates of absorption and retention of moisture in different kinds of materials. Clearly there is a big difference in the types of materials found upstairs than in the basement. This is a major factor in determining humidity levels in both spaces.

 

Thanks for the scientific explanation! I didn't think that people should rush to cut a hole in their wall for an air exhaust.

 

Thank you for your replies; I'll have to check those links and study the information carefully.