Basement Steam ventillation - backdrafting thoughts

[brettwasbtd]

I have researched this to death, and feel I am just paranoid. I have been dragging my feet on making purchases for my basement induction electric setup. Ventilation is my biggest concern as I don't want to pull fumes from other basement gas appliances. The kettle and vent location will be approximately 11 feet from my furnace and 13 feet from the water heater (both gas). My first questions is what cfm fan is really necessary just to remove the steam/evaporation/moisture of 1 to 1.5 gallons an hour? Seems If I can get the hood closer to the kettle it will reduce the need for more cfm. Additionally, is there any good documentation on air systems/backdrafting. I would be fine with cutting an intake air hole, or even an intake air with an inline ductblower (same cfm) to go over the kettle. I have a CO detector. Any thoughts are appreciated - I don't have a window in the room. There is a door about 10 feet away from the gas appliances (22+feet form the brewspaces I could open to let some air through.

 

[geoffm33]

This won't have answers to all your questions/concerns, but I made a similar post, but not in regards to using an inline fan (box fan instead). Perhaps there is some info in there that may help:

https://www.homebrewtalk.com/f170/b...ntilation-negative-pressure-downsides-465058/

 

[The_Bishop]

Distance isn't a factor. What you need is a source of air ingress that's equal to or slightly better then the ventilation to avoid creating negative pressure.

 

[brettwasbtd]

This won't have answers to all your questions/concerns, but I made a similar post, but not in regards to using an inline fan (box fan instead). Perhaps there is some info in there that may help:

https://www.homebrewtalk.com/f170/b...ntilation-negative-pressure-downsides-465058/

Thanks, this definitely had some good info!

Distance isn't a factor. What you need is a source of air ingress that's equal to or slightly better then the ventilation to avoid creating negative pressure.

Thanks, this is good to know. I was considering getting one of those fairly inexpensive inline duct fans for the air coming in from the left side of my rig. The exhaust hood and exhaust would flow out the right side. I do kinda think this is overkill though!

Like I said, I could open the door, which has a poorly sealed storm door which would let air in. Just feel like this could create quite a temp swing in the summer/winter.

If anyone has thoughts on cfm that would help. I see some people say 200-250 works just for evaporation, and other say it doesnt

 

[heckels]

Like you said, you can get by with a lower CFM if you can get your hood close to the kettle.

I'm using a standard range hood and was having issues with the fan that was rated at 300 CFM. Granted, I'm only using 4" ducting. I suspect it was actually only pushing about 200 CFM.

When I say issues, I mean there was significant moisture running down my walls behind and to the side of the kettle with a ton if moisture condensing and falling back in or around the kettle.

I recently upgraded to a 6" 400 CFM vortex style fan but kept the 4" ducting. This didn't 100% solve my problem but alleviated it greatly.

Sent from my iPhone using Home Brew

 

[Renoun]

Are your appliances natural draft and taking combustion air from your basement? Some newer appliances have forced exhaust and draw combustion air from outside.

Do you have laundry in your basement? If the clothes dryer runs without affecting your appliances you can run a moderate exhaust fan and avoid drying clothes while you are brewing.

I'm not at home with access to my reference books but there are formulas for calculating combustion air and makeup air if you have the specs for your appliances.

 

[brewman !]

Are your appliances natural draft and taking combustion air from your basement? Some newer appliances have forced exhaust and draw combustion air from outside.

Appliances that have their own intake and exhaust venting are called direct vent. Examples: *some* hot water heaters, most modern boilers, *some* furnaces, *some* fireplaces.

Do you have laundry in your basement? If the clothes dryer runs without affecting your appliances you can run a moderate exhaust fan and avoid drying clothes while you are brewing.

Not necessarily true. Modern building code usually specifies that you need an inlet pressures sensor when running a big fan. If the static pressure drop is greater than X, you need to run an intake fan as well as an exhaust fan to balance the pressure.

Backdrafting natural draft appliances IS a very REAL ISSUE. Carbon monoxide poisoning can result. Google is your friend on how that ends up.

A call to a local building inspector or HVAC contractor would clear up the situation pretty fast.