Garage ventilation system

[Mbx0187]

Hello everyone,
I have had an idea for getting some air circulation in my garage during this summer. As of recently I have started to spend increasingly more and more time in mine and as the summer sets in I can find myself with signs of heat stress constantly while working on projects. Prickly heat, head aches etc. Once these symptoms show up I stop all work and go inside and hydrate and cool down, normally for the entire day sadly.
Ive also had insulation added above the garage and will have the wall cavities filled with foam or cellulose material once I can make a decision on which will work best with a brick exterior.
As a shift worker I have 7 nights per month off and 7 days. Nights are normally not an issue but days can be unbearable in Houston Texas. I wanted to bounce this idea off some of the folks on the forum. I'm considering a force inducted air flow though my garage and up into the attic and out the powered vent, which are depicted in my drawing below. 1650 CFM units for all 3.
I would like some input from folks who have more experience than I in this area.
Things that I have considered,
1. Completely “balanced” flow will negate the effectiveness of my soffit and ridge vents.
2. Unbalanced drafts could cause positive/negative pressure in the attic pushing hot air into the home or sucking ac up into the attic. (currently sealing all light fixtures and attic ladders)
3. With this system I would also incorporate a dust filter in the garage to attic fan to eliminate saw dust from accumulating in the attic
4. Humidity in the attic could be increased if hot air is introduced too quickly and not removed in a timely manner. (Considering building a Arduino based humidity / temp probe to control the fans via a DC to AC relay system.) I already have all the parts for this left over from a motion sensing doggie door that I built)

 

[pseudorealityx]

Why not just actually COOL the space? Fans will ventilate, but you'll never do better than ambient and Houston summers are brutal.

 

[Mbx0187]

I would love too cool it but I need a means of managing dust as well as move air. Im trying to maximize the utility of the air flow in the garage as well as the attic to improve efficiency.

 

[pseudorealityx]

A dust collection system in addition to an air conditioner would be vastly superior to your solution.

What kind of dust are you dealing with that would stay entrained in the air from the garage, through the attic, to the outside?

 

[Mbx0187]

All kinds, metal fumes from welding and solder, saw dust from massive quantities of MDF and other fibrous board material.

That isn't to say that they are "entrained" but anytime I get a breeze any material that has laid down as been kicked back up into the air. Wearing a respirator at all times while in the garage isn't feasible. I have two 20 inch fans that I use to circulate air in the space while im working.

 

[Stuart in MN]

I would run the exhaust fan directly outdoors, rather than into the attic - depending on how the house is built you may be creating an opening in the fire barrier between the house and garage, and you don't want to be pumping a bunch of dust and fumes up there either.

 

[Mbx0187]

There is no fire barrier between the house and the garage sadly. I've spend several hours building storage above my attic and saw nothing there. The attic is one continuous cavity above the home. It was constructed in 1978. I was looking into the tjernlund fans with the heat sensitive fusible link that would slam the shutter closed as opposed to blowing a flame into the attic. I do run dual smoke and co detectors in my garage, even though my home is 100% elective with no options for nat gas.

http://www.tjernlund.com/cool_breeze_garage_cooling_fan.htm

 

[barnjunkie]

I was looking at possibly installing some Greenhouse fans in my pole barn, but I do not know if that is what I need.
I like these because they can be put on a timer and have variable speeds.

 

[pseudorealityx]

All kinds, metal fumes from welding and solder, saw dust from massive quantities of MDF and other fibrous board material.

That isn't to say that they are "entrained" but anytime I get a breeze any material that has laid down as been kicked back up into the air. Wearing a respirator at all times while in the garage isn't feasible. I have two 20 inch fans that I use to circulate air in the space while im working.

A general exhaust fan isn't going to do much for the sawdust. It's too heavy and will settle too fast. General ventilation will help with the soldering and welding, but a localized system (if feasible) would be far better.... better yet, just opening the garage doors if you're doing heavy welding.

Again, you started this thread complaining about heat, and now you've got a machine shop and wood shop in there... a bit different issue.

 

[James-W]

I use a dust collection system that I bought several years ago. The system does not vent outside so you don't lose any cool air from your shop. The system collects the wood chips and the sawdust and it also traps about 95 percent of the tiny dust particles. I am sure there are even better dust collection systems today than there were back when I bought mine. Perhaps this would be an option when used along with an air-conditioner.

 

[Mbx0187]

I just so happen to be getting a dust collection system for Fathers day. Harbor freight system with the 2 stage baffle canister on the suction side. Ill consider portable AC system. I would like to do a trial run with a unit on a hot day..

 

[NUTTSGT]

How much insulation did you put in the ceiling ? Since you deal with severe heat, when you insulate the walls, you might want to consider adding some extra depth to your wall studs for more insulation.

Welcome to GJ and let us know how the trial run goes. You also might want to edit your profile to add your general location. It helps your fellow members answer your questions more accurately.

 

[nadogail]

I have recently salvaged a blower fan assembly from a furnace, with the idea of enclosing it in a box where the suction will be drawn through furnace filters.

A true low budget air cleaner.

 

[BadgerBoilerMN]

You must lower the dew point using a mini-split.

Spot exhaust to the exterior wall and consider an energy recovery ventilator.

Attic exhaust systems are very questionable devices to start with, but in humid climates they make no sense since the latent heat is the thing you want least and have most.

 

[pseudorealityx]

I just so happen to be getting a dust collection system for Fathers day. Harbor freight system with the 2 stage baffle canister on the suction side. Ill consider portable AC system. I would like to do a trial run with a unit on a hot day..

Don't waste your time with a portable A/C. If the budget is tight, consider a window style unit.