Exhaust Fans

beamish

Evolving Lead Gorilla
http://www.fantech.net/inline_duct.htm

I got the 750 cfm one for my home office/smoking room. On a variable rheostat so under normal circumstances it is very quiet at a lower speed.

these work excellent I have installed numerous fans like this,I have found that metal duct works better,less restriction,also for a direct ceiling mount fan check out the panasonic whisper quiet series they are so quiet you can hardly hear them, for bath fans and such these are great.
 

LEOinFL

Young Chimp with a Gun
Question time....
I use a box fan in my mancave..turned to suck the smoke out of the room and blow it through the window.
Would closing off the window around the fan, so air can only be pulled through the fan, increase its efficentcy? I tend to think it would, but wanted another opinion before I go through the work of closing it off.
OR
Am I better off just getting an exhaust fan and instaling it?
Trying to go the least expensive/most efficent way.

LEOinFL
 

c2000

Cigar Whisperer
I have a triple insulated garage that I smoke in during the winter,,I am going to purchase a Value tech fan from Farm tek (on line) its a variable speed fan that on low has a 300 cfm rating and on high has a 1,050 cfm rating. the fan is a plug in model so no fishing wires through the insulation. $179.00.. Does this sound like a good fan for my purposes..?

Jerry in Minnesota.
 
Question time....
I use a box fan in my mancave..turned to suck the smoke out of the room and blow it through the window.
Would closing off the window around the fan, so air can only be pulled through the fan, increase its efficentcy? I tend to think it would, but wanted another opinion before I go through the work of closing it off.
OR
Am I better off just getting an exhaust fan and instaling it?
Trying to go the least expensive/most efficent way.

LEOinFL

Probably a bit of efficiency increase. The biggest benefit would be the "negative pressure issue". The make-up air would have to come from inside your home, drawing air into the room at a higher level than now given the easy access from around the fan. :Edit - Meaning that no smoke gets into any other part of the house: Pretty easy/inexpensive to build something, even cardboard type surround around the fan to seal it up when you put it in the window.
 
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Sancho

Ted Peffer fan club
I may not have built a room, or designed ductwork but I do know a few tidbits about making things quiet :ss

Do not restrict the size of the ducting down after the blower, this is pretty logical in that you will create a high pressure zone directly after the fan before it goes to the outside. This pressure will boom back down the piping into the room, the exact frequency is based on a number of things but the primary contributors are fan speed and pipe diameter. Furthermore this buffetting air will put a load on the fan that you do not want possibly shortening the life of the unit.

Some things to think about to get the room quieter:
-Rigidly mount the duct work such that it can not shake, squeak or rattle when the unit is operating. This is especially importent for the grills that often cover the vents in the room as in many cases they are not rigid to the fan and simply clipped in place
-Avoid sizing the fan/duct such that you build a standing wave tube which be very very annoying to the occupants. (some math required)
-centrifical blowers are more efficent but louder generally when they are in their efficeny zone, to that end standard "pancake" fans are better due to the lack of ball bearings etc. consider either springing for a balanced fan (balanced all the way out of operating band, some are only balanced a few hundred hz out) or do it yourself with pennies or other small weights that can be affixed to the blades to shift resonances

Lastly, the ducting itself can be damped by using constrained layer damping material. This is basically a fancy name for tar or a substitue and an aluminium backing sheet. Science tells us this when applied to a surface puts it into double shear essentially stiffening the panel or in our case duct. This is available in the roofing ection of most home depots and lowes as temp. shingle repair sheeting its a 25' roll about 6" wide.

Always follow the rule of Pi, you will use 3 times as much as think you will need. In Daves case an acceptable fan size for four people is ~2700 cfm
 

ryan35um

Young Ape
What size room are you suggesting 2700 CFM for? My cigar room is 8x12 and my 1200 CFM fan is more than plenty. We have three people smoking in there often and I usually still never have the variable speed controller for the fan set to more than 1/2 or 3/4 strength. If someone were to use 2700 CFM or anything in that ballpark you'd want to be using multiple fans rather than one exit point, otherwise you'd be creating some crazy air flow patterns in the room.

]

Always follow the rule of Pi, you will use 3 times as much as think you will need. In Daves case an acceptable fan size for four people is ~2700 cfm
 

Sancho

Ted Peffer fan club
What size room are you suggesting 2700 CFM for? My cigar room is 8x12 and my 1200 CFM fan is more than plenty. We have three people smoking in there often and I usually still never have the variable speed controller for the fan set to more than 1/2 or 3/4 strength. If someone were to use 2700 CFM or anything in that ballpark you'd want to be using multiple fans rather than one exit point, otherwise you'd be creating some crazy air flow patterns in the room.

Im not disagreeing with you, Im merely suggesting the rule of three be followed as it allows you to massively over engineer the solution such that future upgrades are not needed. As you said, multi exit ports is going to be superior for a larger room simply because like in your room there is a noticable flow pattern and multiple fans are going to creat wicked turbulence. I also suspect that as room size increases, the required fans flow rate increases exponentially althoghu I have nothing that supports that. Merely a hunch...
 

(909)

X Canadian
What size room are you suggesting 2700 CFM for? My cigar room is 8x12 and my 1200 CFM fan is more than plenty. We have three people smoking in there often and I usually still never have the variable speed controller for the fan set to more than 1/2 or 3/4 strength. If someone were to use 2700 CFM or anything in that ballpark you'd want to be using multiple fans rather than one exit point, otherwise you'd be creating some crazy air flow patterns in the room.

8'x12' floor x 8' (assumed ceiling height)= 768 cubic foot. At 1200 cfm (cubic foot per minute)you are getting 1.56 air changes per minute. That's more than plenty for a smoke filled room! One air change per minute would be minimum for a smoking area.

The only thing I am curious about is where that air is being made up. Did you open a window to let the air in? If you are exhausting 1200 cfm, you need 1200 cfm to make it up, where are you getting make up air?
 

ryan35um

Young Ape
8'x12' floor x 8' (assumed ceiling height)= 768 cubic foot. At 1200 cfm (cubic foot per minute)you are getting 1.56 air changes per minute. That's more than plenty for a smoke filled room! One air change per minute would be minimum for a smoking area.

The only thing I am curious about is where that air is being made up. Did you open a window to let the air in? If you are exhausting 1200 cfm, you need 1200 cfm to make it up, where are you getting make up air?

Rudder and I have a similiar setup. We are getting the make up air from outside. We have ducting running from the outside of the house to the room (not a forced air setup, the exhaust fan pulls the air as needed). Assuming you live in climates that have extreme hot/cold weather you'll need a duct cooler or duct heater to make sure the air comes in at a comfortable temp.
 

NAV3

Young Ape
I've been dying to be able to smoke a cigar inside my apartment for the longest time but the lack of ventilation and the lingering smell have always turned me away from it. I have been thinking of getting a window exhaust fan as I can't do any modifications to my current living space because I am renting. Any suggestions?

Thanks,
Andrew
 

Dgar

SilverBack
I've been dying to be able to smoke a cigar inside my apartment for the longest time but the lack of ventilation and the lingering smell have always turned me away from it. I have been thinking of getting a window exhaust fan as I can't do any modifications to my current living space because I am renting. Any suggestions?

Thanks,
Andrew


Put your fan in the window, pull a chair up close, light a couple scented candels, enjoy your cigar. actually I dont smoke in my house during the summer much but there have been times especially in the winter where I might smoke one or two a week in the house. But just using a fan and letting it run for 30 minutes or so after your finished smoking should be fine. Maybe spray a little fabreeze, put down a little carpet fresh when your done and it's all good :D I would like to have a nice room and a real exhaust sysytem someday, I prefer smoking indoors, just hard to find places.
 

Tristan

Pretentious.Bastge.Online
This is a great thread. I am going to be installing ventilation in what will soon become the smoking lounge/coffee roasting room. I want to start on this project in a few weeks, but am doing serious research and working out the budget in the mean time.

When you fine gentlemen installed your ventilation, was venting out the side of the house a difficult task? What did you use to create the hole for the exhaust ducting? I'll be creating a hole in the concrete block wall.

Cosmetically, what does it look like from the outside of the house? Is it similar to the look of a dryer vent from the outside?

I've got boards 24" on center and haven't started on framing the room. It will be 12.4' X 15.5' and the ceilings will be 80" high, so low ceiling.

I was thinking of putting the most powerful fan I can fit. I am almost thinking of going with this:

http://www.ventingdirect.com/index....anufacturer/FanTech/categoryId/3731/finish/NA

but will most likely go with this:

http://www.rewci.com/fa8521cfminc.html

What does the actual vent in the ceiling look like in your smoking rooms? Can someone post a picture or a link to what you would recommend?

Any other items you fine gentlemen recommend besides a variable speed control?
 

ryan35um

Young Ape
When you fine gentlemen installed your ventilation, was venting out the side of the house a difficult task? What did you use to create the hole for the exhaust ducting? I'll be creating a hole in the concrete block wall.
I had to have a specialist make the final ducting exhaust piece to get over and out to the side of the house since I was squeezing the ducting between some wood beams. To create the hole in the side of the house I used a sawzall.

Cosmetically, what does it look like from the outside of the house? Is it similar to the look of a dryer vent from the outside?
I have photos of this posted on http://www.ryandeyer.com/cigarroom/cigar_room_photos.html

What does the actual vent in the ceiling look like in your smoking rooms? Can someone post a picture or a link to what you would recommend?
I used a 14" grille cover. I have photos of this posted on http://www.ryandeyer.com/cigarroom/cigar_room_photos.html

Any other items you fine gentlemen recommend besides a variable speed control?
Must sure you are bringing in as much air into the room as you are exhausting with the fan. Otherwise you'll deprive the room of oxygen and create a negative pressure that won't be desirable.
 

boonedoggle

Goal: 1,000,000,000 posts
I use a Honeywell window fan with reversable fans...so you can exhaust, or freshen your room with air from outside. This fan has lasted over two years, and even though the fans have turned brown from the smoke going through, she still purs like a dream. You can get em cheap at the Home Depot and such...but, you have to have a window to go this route.
 
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