Compressor aftercooler cooling fan? Attic ventilation?

[cadunkle]

I installed a Hayden 1290 cooler between my compressor and primary tank today. Goal is less water in the air as I'd like to try painting.

It drops about 105* from the compressor discharge which is a small aftercooler in the airflow from the flywheel. After a tick over 9 minutes to fill the system from empty I see 235* at the discharge from compressor and 130* at the bowl of the filter/separator between aftercooler and tank. I did see 290*-300* at spots of the second stage of compressor head and inlet of the build in aftercooler. Ambient temp is 111* in the compressor room (attic of shed). Outside temp around 75* and downstairs of the shed is 80*.

Obviously I need to cool down the attic both for cooler air and compressor longevity in the summer. There are only two very small gable vents. I was initially thinking to add a larger passive gable vent on each side of the shed (https://www.lowes.com/pd/Air-Vent-15-75-in-x-26-5-in-White-Rectangle-Aluminum-Gable-Vent/1000487383). That should give some drop in attic temp, particularly since the prevailing wind is on the opposite gable end. I don't know how much ventilation area is appropriate for the space (16'x16'), but anything would be an improvement.

Then I got thinking a fan might be a good idea. I have a magnetic starter wired up so could get 120v or 240v easily enough when the compressor is on or use a thermostat. Gable vent fans I see are pretty deep though and I only have about 3.5" between the aftercooler and inside of the sheathing. I suppose I could box it out for more depth but most power gable fans I see are closer to 12" depth to the back of the motor.

What would you guys do for attic ventilation? How about a power vent behind the cooler, worthwhile and any lower profile options?

 

[rdoty]

I built a frame with a sheet metal back and an 8" computer fan to pull air through the radiator - drops the exit temp down to ambient. Added an automatic float drain which works great - I end up with almost no water in the tank. Build details at Aftercoolin'.

A setup like that, pulling from the outside vent, should do the trick. Optimally you could seal the front of the Hayden so that it is pulling all air from outside.

 

[kbs2244]

a 10 dollar drug store fan blowing across the front of those fins will do a lot
no need to over think it

 

[FredWanaker]

you need to drop the attic temp with more soffit vents and probably a ridge vent. Years ago I added a whole house fan, and as a result had to add more gable end vents and soffit vents. The temperature in the attic went from about 130F to 90F. That said, during the summer I have to blow ambient air with a fan into the shed where the air compressors are or I begin to smell oil in the compressor air. One cannot run compressors in 110F air without getting better cooling across them. You might consider some form of gable fan - HOWEVER I did have several many years back and they do not last nor do they do much to cool an attic. But you could aim them at the compressor. You do know that the heat from that compressor is going to add significantly to the heat in the attic unless you do something to get air flow thru there.

 

[isb cornbinder]

I have one of these on the garage and two on the house. They work really well. The drive is the rising hot air. NO electricity is needed.

Does My Home Need Attic Ventilation Fans | Direct Energy Blog

 

[cadunkle]

Yes I definitely need more ventilation to drop attic temp. I picked up two of those fairly large gable vents today and got one installed behind the cooler before I was pulled another direction. Maybe tomorrow I can get the other one installed.

I had considered a ridge vent in the past, not sure how well it'll work with gable vents since this is a gambrel roof and I can't do anything for soffit vents. or maybe just having anything additional for ventilation will help?

I did take a quick peek up top this afternoon and saw about 120*-125* roof sheathing temp but closer to 100* ambient measuring temp of objects inside with the IR temp gun. So one larger vent seems to have helped somewhat.

Not sure what options are available for insulation or radiant barrier, given the gambrel roof?

I wonder how much temp reduction additional venting can offer, given the OSB under the shingles is 120*+ radiating through the bulk of the day. Granted most of my work in summer is morning to early afternoon, so the compressor doesn't run much or at all in the hottest part of the day but I'd like to be able to use it with no worries regardless of temp.

In that regard maybe the fan rdoty used would help, perhaps oriented to exhaust hot air through the cooler. not ideal, but it may help cool overall attic temp when the compressor runs. It would be easy to wire up one or a few to run while the compressor is running, or just a box fan (cheaper) mounted behind the cooler now that I have a gable vent there.

 

[FredWanaker]

you need air in and air out to cool. You also need to consider winter months depending where you live, All I know is that when it is 100F here and more, I have aim a 24" fan into the 10 x 12 shed I have to keep the compressors from overheating.

 

[rdoty]

It doesn't look like you have a drain on the Hayden. The Hayden will condense most of the water out of the air. If you don't drain it at the radiator it will end up in the tank, just like not having an aftercooler. I installed a drip leg and an automatic drain between the radiator and the tank. Works great.

 

[cadunkle]

There is a Norgren water separator with automatic drain after the cooler.

I think I may get two more of these vents, since they are installed offset to one side of the shed. I can use four of them and have the exterior symmetrical. Cold is a consideration in winter. Lows are usually slightly below freezing and highs in 30s or 40s. I could block the vents in winter if prudent, but I don't think our mild winters are as much of an issue as 110*+ up there in summer.

 

[Monza Harry]

I will suggest that you add a very low restriction intake to the shed interior [or the outside which ever is cooler]. If the inlet air is cooler the exhaust air should be cooler. Ducting the coldest air possible through that aftercooler is also absolutely essential for max temp. drop. So if I read the post correctly you are drawing through that gable vent, I would shroud that to insure no style warm attic air is drawn through. I LOVE the mag starter controlled fan, and then shroud that with an outdoor vent location (is the opposite end of shed possible?). These ideas should help better your already good results. Harry

 

[cadunkle]

Good idea on the shroud to draw air through. You got me thinking about intake air. The intake is currently in the attic plumbed through a glasspack and larger compressor filter/silencer assembly. Maybe I should plumb that to pull from near one of the attic vents for cooler air. I could plumb it outside I but the idea was to keep compressor noise contained.

I suppose I could go off another side of the shed away from the house and garage, it's a good distance to neighbors off those sides so may not be too loud at 170' to neighbors off one side or 250' off the other side. Either way, getting 30*+ cooler intake air would help, depending on attic temps after I get all the vents installed. Or may hurt with moisture when it's raining if I pull from outside?

 

[racecougar]

From the photo above, I had figured you were already pulling outside air for the compressor inlet (based off what plumbing is visible on the inlet side). I would absolutely do so, unless you have a source of conditioned air to pull from (if the first floor of the shed is conditioned, that would be best to draw from). As it is, you're asking a lot of that system by compressing air that is already well above ambient, in a room well above ambient.

 

[The Tool Tyrant]

You're missing one vital aspect of cooling, and that's the pump & motor themselves. You have the compressor jammed into a corner with hardly any headroom! If you want your compressor to last a while, I suggest that you mount a vertical fan behind the receiver about 12" off the floor so it can blow cooler air up the stud bay and over the pump head.

Adding a powered gable end fan with sufficient intake air at the opposite end will help drop the ambient temperature immensely.

 

[Monza Harry]

Good idea on the shroud to draw air through. You got me thinking about intake air. The intake is currently in the attic plumbed through a glasspack and larger compressor filter/silencer assembly. Maybe I should plumb that to pull from near one of the attic vents for cooler air. I could plumb it outside I but the idea was to keep compressor noise contained.

I suppose I could go off another side of the shed away from the house and garage, it's a good distance to neighbors off those sides so may not be too loud at 170' to neighbors off one side or 250' off the other side. Either way, getting 30*+ cooler intake air would help, depending on attic temps after I get all the vents installed. Or may hurt with moisture when it's raining if I pull from outside?

I was thinking more of from inside and as noted in the posts by @racecougar and @ The Tool Tyrant that conditioned air will be best, cooler and drier air in will be cooler and drier air out. And as TTT points out overall heat conditions matter probably more than most of us understand! I understand your noise concerns but intake noise is probably the easiest to mitigate, go from your compressor intake and then go to a 3"ABS pipe to your interior then add a larger air filter elbows will help as will wrapping that pipe in fiberglass or Roxul insulation. If not enough a twisted baffle will ad some quiet. If your intake is behind a cabinet that is a good muffler as well. Harry

 

[dcg9381]

What would you guys do for attic ventilation? How about a power vent behind the cooler, worthwhile and any lower profile options?

Is this attic above the garage? I have soffit vents, but in the attic/garage ceiling, I installed an "attic fan" that's on a thermostat. I'm not cooling a compressor in the attic like you, but what I am doing is triggering a fan to "pump out" the head soak from cars that park in the garage. An attic fan, ridge vents would work.. Roof vents, maybe a larger vent next to that compressor - just a place for the air to exit. As long as you create positive pressure up there and have a way for that air to go, it'll work.

In terms of reducing attic temps passively, the best option (and most expensive) is spray foam.
Second best is probably a radiant barrier.

 

[Ike Carlson]

cool air is a must for air compressors. Get the attic temps down and it will run better.