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njlou
Re: wave ventilation

Here is a picture. They dont give much space but you may be able to see it (sideways).

njlou
Re: wave ventilation

Your concerns for negative air pressure are valid. Let me further explain. The purpose of any exhaust fan is to provide negative pressure, if it doesn't, it's not working. You need an open end somewhere to create the flow.
My "Hatch" open area is like an open window.
It relieves the "confinement" issue so all suction is neutralized. It is the same as using a vacuum pump outside vs in a closed chamber. My oil burner has the same or more air available and in reality is not in competition with the fan. If i seal up the hatch door i may have an issue, however in the winter (dry time)i intend to shut down the unit and close the door via installation of the glass.

canuk
Re: wave ventilation

Nice & neat install .... that fan looks identical to the central exhaust fan I installed for my bathroom.

Quote:

My "Hatch" open area is like an open window.
It relieves the "confinement" issue so all suction is neutralized

While this does relieve some of the confinement you can't be sure the amount of air entering the "hatch" is identical to the amount of air being exhausted ..... afterall wouldn't that be the way it would become neutral?

Quote:

My oil burner has the same or more air available and in reality is not in competition with the fan

Unless you have measured the CFM's being exhaused versus the CFM's being introduced from the "hatch" as make up air .... you have to be cautious the exhaust isn't more than the make up .... the air being exhausted has to come from somewhere.
This is more important in those spaces that contain combustion equipment.

Personally I prefer the air/air exchangers or the HRV/ERV which are a balanced exhaust system....... meaning there isn't negative pressure since they replace the same amount of fresh air as exhauted air from the home.

jdonajko
Re: wave ventilation

Thanks for the pictures and ideas.

My basement has a sub-slab vent. I guess it would be for passive radon mitigation. I was thinking I could T off of the PVC vent pipe and add the radon fan and get some ventilation for the basement and make the radon mitigation somewhat active.

Any thought on this? Bad idea?

canuk
Re: wave ventilation

jdonajko .... the purpose of the under slab ventilation is to provide a continious uninterupted path to the outside for exhausting the Radon gas .... either passive or active.

If you're suggesting to " T " into the Radon vent pipe for using it for exhaust venting the open basement area .... Bad Idea.
You will have one end open to the basement which could allow the Radon gas to seep through that " T " into the basement .... defeating the intended purpose of the Radon vent system.

jdonajko
Re: wave ventilation

I did think about that, actually. I was thinking that I would install a valve on the branch so that I could prevent any back leakage during times of non-operation.

Allen80
Re: wave ventilation

i've seen a lot of posts concerned about negative air pressure. I looked at the cfm that the wave unit expels when on high and it's nothing compared to an attic fan. an attic fan will exhaust 10 times as much air. also, a bathroom fan and kitchen exhaust also expel air. if your home is so tight that you cant get the wave unit then make sure not to turn on bathroom fans, kitchen exhaust or attic fans. the reason i'm saying this is because i had one of their older models installed a few yrs ago and i have no issues of negative air pressure, my basement is not humid and does not smell. i called just to check out the price recently and tehy quoted me a lot less than $1700.

bosland
Re: wave ventilation

Can anybody post specifics about the homemade wave ventilation system? I would like to build one similar to the picture that's in this thread but I would like to know more about the materials used and any other info about building my own.

njlou
Re: wave ventilation

Hi
This is the fan I used:
http://www.rewci.com/fahprain4or51.html

This size can easily handle 1500+ sqft.

It works great!! Remember this is a ventilating fan that is rated 24/7 for like 10 years. the entire system cost ~$200.
OK I used some old hardware and PVC pipe so I saved a few $$.

Bathroom or window fans arent even rated and I would not trust them to run continuously. Additionally, mounting them is difficult, since they would need protection from rain etc.

I used 4"PVC pipe, some hangers,and an exit vent to outside.
I used their couplings, and their exterior "T" (I also added a small screen to keep critters out). Install the bell ends on each side of the fan so that the couplings match.
I installed at my existing window which I replaced the glass with plywood covered with sheet aluminum. That way I didnt have to cut the wall and it was in the right place etc.
The grey "X" that you see is just window security to prevent entry through the windows. I had that installed previously. Make sure that you put the intake "pickup" on the floor since thats where the nasty air resides.

Just get an idea from my picture and adapt to fit your situation.
BTW, I shut down the system in winter and cover with plastic since I dont want cold air in. Also the winter humidity is very low , and it has no issues. In winter the house is buttoned up much tighter such as the door to the hatch has the screen replaced with glass etc., and it would then cause the neg pressure as noted above and change the draft to my oil burner.
IMHO, i think that this system may expel some radon with the other nasty air. Better than nothing!!

NOTE: If you have a radon system, dont mess with it or use this additional system since the existing radon system was put there because it is needed. The new system may conflict with the radon system.

bosland
Re: wave ventilation

Thanks for the info. I thing this will help.

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