Choosing refrigerated air dryer for air compressor

[Bmw4life]

These units seem pretty small, and not overly expensive, and a lot less hassle than building copper pipes, radiators etc.

My air compressor is 80 gallon 2 target, 17 cmf at 90 psi.

I'm looking at these 2 dryers, but can't seem to figure out any difference.

DryStream 25 CFM Refrigerated Air Dryer

Refrigerated Dryers cool compressed air by mechanical refrigeration and removes water vapor/condensation by a moisture separator. Condensation is automatically drained reducing maintenance. Dew point Indicator checks the air quality level at a glance. Qui

www.kmstools.com

SMC 110V 25 CFM Refrigerated Dryer

IDF refrigerated air dryer series, in compliance with the Montreal Protocol Regulations, uses refrigerants

www.kmstools.com

Is it just the brand? Is one better than the other? Do these require maintenance? Do you plumb them between air pump and air tank or at air compressor outlet?

I was thinking of building something with a radiator, but considering the time and effort required, maybe this would work better.

 

[Beerhippie]

A refrigerated dry gets the air MUCH dryer than using ambient shop temperature and a radiator.

I'm not familiar with either of those, so no comment there. Just size the dryer to match the output of your comp--or a little more.

The dryer between the comp. and the tank is great--IF you have an air-air cooler before it. Otherwise, you're severely over-loading the refrigeration unit of the dryer. Air right out of the comp is HOT.

The refrigerated dryers don't require much maintenance--about the same as your kitchen 'fridge. Keep the condenser coils clean and that's about it. Check that the drain valve is actually opening occasionally--usually a timer setting in the menu of the unit--as a stuck drain valve can overheat the compressor of the unit--I just killed one this way.

Your tools will love you for using a dryer.

 

[danielbuck]

a radiator type setup directly after the compressor with a water trap isn't that much work to do. I would probably do that before a refrigeration unit anyway. Personally I like using a separate radiator fan with the radiator not directly next to the compressor.

 

[1redTA]

why do you need a refrigerated air cooler?

 

[1redTA]

the trans cooler after the compressor keeps the media in my blast set up dry wita water separators pre and post tank

 

[KwikFab]

I use the Harbor Freight refrigerated air dryer and it removes a ton of moisture every day I use it.

I've got a bottle at the end of the drain line and it'll fill up a bottle in just a few weeks time.

My coalescing filter, desiccant beads, and water separator that all run after my air dryer all remain dry.

No complaints here.

 

[KwikFab]

why do you need a refrigerated air cooler?

It helps to pull moisture away from air.

 

[KwikFab]

I also remember Northern Tool doing a big clearance on their Speedaire refrigerated air dryers over a year ago or so.

The $2,000+ models were selling between $200 - 400 each, all unused in-stock units.

 

[1redTA]

It helps to pull moisture away from air.

I understand that, but why do you want a refrigerated system? I ask to try and help

 

[Beerhippie]

why do you need a refrigerated air cooler?

In our case, compressed air operates automated valve systems, pneumatic-powered equipment w/lots of expensive pneumatic cylinders and power tools.

All of those are much longer-lived running on Sahara-dry air.

Pneumatic cylinders and actuators in particular last much much longer since we installed a refrigerated air dryer.

I understand that paint guns work much better on it, too.

 

[1redTA]

my system puts out very dry air for my use in nw Florida and works fine

 

[KwikFab]

I understand that, but why do you want a refrigerated system? I ask to try and help

Ah gotcha, sorry I misunderstood.

 

[1redTA]

Ok, do you have issues with the current system? I would make sure that any refrigeration unit is able to keep up with your systems need

 

[KwikFab]

Ok, do you have issues with the current system? I would make sure that any refrigeration unit is able to keep up with your systems need

I think we're all waiting for the author to come back and reply

 

[1redTA]

I think we're all waiting for the author to come back and reply

sorry I had the check on the ap that there was a response

 

[KwikFab]

sorry I had the check on the ap that there was a response

Naw you're good. I'm just a random dude sharing my experience on one air dryer, and suggesting an alternative.

Only reason why I didn't grab one of those nice Speedaire units is because we don't have Northern Tool in CA.

I'm a mod in a CNC FB group so I see all the stuff posted there. I remember the news spread like wildfire about NT running a clearance on ALL Speedair refrigerated air dryers in stock at every location.

People posting pictures of the units with a yellow label for $500, only to continually get marked down until sold.

Several people bought more than one to sell them on marketplace.

 

[1redTA]

I have no response to give in this situation and wish you good luck!

 

[Beerhippie]

I just checked NT's Store Locator: There are no stores with in 100 miles of Oregon.

I'd buy a half-dozen at that price and never worry about maintenance again!

 

[LopezBart]

For those who don't know, as air goes down in temperature, its ability to hold moisture as vapor decreases rapidly. So these refrigerated coolers cool the air, remove the moisture, and then let it go warm up again in the lines. This means that the air is much drier (lower relative humidity, which is how full the air is compared to the maximum it can hold at a particular temperature) and causes fewer problems in tools, sandblasters, painting, etc.

 

[Beerhippie]

For those who don't know, as air goes down in temperature, its ability to hold moisture as vapor decreases rapidly. So these refrigerated coolers cool the air, remove the moisture, and then let it go warm up again in the lines. This means that the air is much drier (lower relative humidity, which is how full the air is compared to the maximum it can hold at a particular temperature) and causes fewer problems in tools, sandblasters, painting, etc.

Thanks!

More important than relative humidity, in this case, is absolute humidity.



Why? Because as the compressed air decompresses, powering your tools or whatever, it gets cold--sometimes really cold. With an absolute humidity below that cold temp, you don't get condensation in your tools or equipment.

If you've ever had a nice cold drink in the tropics, you've seen a great demonstration of absolute (and relative) humidity: The entire table is soon covered in condensate water.

 

[LopezBart]

Thanks!

More important than relative humidity, in this case, is absolute humidity.



Why? Because as the compressed air decompresses, powering your tools or whatever, it gets cold--sometimes really cold. With an absolute humidity below that cold temp, you don't get condensation in your tools or equipment.

If you've ever had a nice cold drink in the tropics, you've seen a great demonstration of absolute (and relative) humidity: The entire table is soon covered in condensate water.

So as long as the expanding & cooling air doesn't get to 100% relative humidity in the tool, there won't be any condensation... so the trick is to get the air cooler than it will be in the tools, remove the condensing moisture, and then let it warm up again before going to the tools. Either way works....

 

[Chris_Hamilton]

I'm not usually a fan of Harbor Freight but their refrigerated air dryer works well in small to medium size compressors. 25 CFM would be about the max you could use the HF model with. I know of multiple guys using the HF for years now and they are very happy with the results. I don't have a HF I have an IR that was given to me by a friend who demo'ed a factory in a nearby town. Happy with that and it makes such a difference.

As for the Gent who asked why? You can get away with not having one or making something to help condensate the vapor but if you are painting (auto refinishing) you want as dry air as you can get. I had a 4 quart desiccant filter at the end of my (properly designed) line and it would saturate in a day. Modern paint systems don't like water and materials are hideously expensive these days. Just purchased 4 liters of Glasurit 55 base coat, and the cost was over $2500. So anything you can do to cut down on water issues and vapor is money well spent.

If you are working the compressor hard you are going to make a lot of water. Even a well designed system that doesn't use a dryer will make water at some point. Try using a pressure blaster all day and that will become apparent.

If one is a light duty user then a well designed air piping system will work suffciently well without a dryer.

 

[Beerhippie]

Where you really notice the difference between relative and absolute is in your compressor tank. Around here, we often have high relative humidity in the winter--60-80% and my compressor tank--drained at least once a day--just dribbles bit. In the summer, with temps from 80 to the low-triples and relative humidity of less than 40%, the tank will flood the shop floor every time. Air usage is pretty constant year-'round.

The same goes for whatever you plug into the end of the hose. You'll get condensation when the dew point of the air leaving the tool is higher than the ambient air, but when the absolute humidity is high, you'll have mist spraying out the exhaust. Before installing the refer dryer, I'd often have wet hands when using a die grinder in the summer. That was relying on standard coalescing filters.

 

[Bmw4life]

Wow didn't expect so many replies!
For me, the only reason I have an air compressor is for sandblasting.
That's why I want/need dry air.
I feel like repeating myself, but yeah, it's easier for me to buy a single $1000.00 refrigerated cooler than plumb a bunch of filters, copper lines, radiators etc. Especially if that thing doesn't require much maintenance.
Just not sure which one to buy, which is one $1000 and the other one $2000

 

[Beerhippie]

Wow didn't expect so many replies!
For me, the only reason I have an air compressor is for sandblasting.
That's why I want/need dry air.
I feel like repeating myself, but yeah, it's easier for me to buy a single $1000.00 refrigerated cooler than plumb a bunch of filters, copper lines, radiators etc. Especially if that thing doesn't require much maintenance.
Just not sure which one to buy, which is one $1000 and the other one $2000

I just bought a replacement for the IR that died on me. $1500, so that's splitting the difference!

 

[KwikFab]

Friend and I have both been doing CNC plasma cutting for a few years.

Granted I only run my setup about 3-4 times per week, my friend runs his anywhere from 4 hours to 8 hours 5 days per week (although many times 7 if he's not at shows).

We both have the same HF dryer.

In my case, I have a far less-than-optimal air setup due to my small tank (25 gallon) and low efficiency (only 6.7cfm I believe) so my air compressor goes off quite a bit during long cut sessions. This means my air dryer really has to work to cool down my air to help pull moisture from it.

On the other hand, my friend has a larger 80 gallon compressor with electronic auto-drain along with multiple separators. Even though his air compressor isn't going off as often as mine, he's running it every single day.

This doesn't answer your question about which unit to choose. I just think the price differences would be with maybe the components used?

Any way you can pull up owner's manuals and the sort to look those items up, along with replacement parts?

If my air dryer died tomorrow, I won't be hurt by it based on the cost and how well it's served me. But parts are pretty generic so they can easily be sourced. I couldn't see myself wanting to spend much more for an air dryer knowing how basic they are in terms of what makes them run.

My consumables do appreciate it though. Here's over 1,000 pierces and not a single swirl mark on the electrode.

 

[MichaelP]

I don't know how long your sandblasting sessions will be and how often you do it during the day. Are you going to run the dryer whole day or switch it on prior to each session (I guess it will need some time to get ready).

I thought about one for my home workshop (sandblaster and plasma cutter are only two tools of mine that would really benefit out of extra dry air), but then changed my mind because of the hassle with turning it on and off. I installed a copper pipe cooling section, and the compressed air is very dry after it. I auto drain my tank a few times a day. Being a "belt and suspenders" type of guy, I also have water separators and desiccant beads filter before those two tools. And I live in a pretty humid climate, but those methods solve the issue for me without extra headaches.

I'd invest into a refrigerated unit only if I go into painting or use plasma and sandblasting whole day long. But I won't.

 

[Sumboodie]

Would piping in a dorm fridge do it for way less than $2000? Like 10% of that.
Or take up a shelf in the beer fridge.

 

[cannuck]

I have no experience with budget price dryers, but have built continuous flow systems able to deliver -40 dewpoint (i.e. VERY dry) air using compressor > refrig > "wet" tank > regen absorpt > dry tank. With a 5HP screw, that's a $25k bill. For general shop use just the refrig plant alone should be adequate. Air contains a great deal of water and we can tell how much by measuring the dew point (temp where moisture in air begins condensing). If you just go from atmosphere through compressor into your tank, 100% of that moisture will end up in the tank and much of that into your air system and tools. In a 5HP continuous flow described above, I can usually see 5 gal./day from the wet tank AFTER the refrigerative cooler (thus why the second stage of regenerative drying).

From the two systems in question: the SMC is 3/4" in and out and a pretty basic unit from a Japanese company (probably made offshore to them). The Drystream is definitely a premium machine, 1/2" in and out. You can see it's value in the digital dew point meter and claim of +1 to +4C air. NO refrigerant can do any better (or it will freeze up) but the good stuff will come as close to zero as it can while the bargain units won't push the limits.

IMHO your budget is what should limit your choice. The SMC will be able to significantly improve your air system and the Drystream will do a measurable bit better.

 

[Bmw4life]

Thanks I appreciate the advice!
I'll grab Drystream. Found it on market place for $1000.

In the meantime I realized that my air compressor noise is really bad lol.
Apparently that has to do with RPM, and the lower the number, the lower the noise.
I couldn't find rpm information on my model, but I'm going to do some research into quieter air compressors. I feel bad for my neighbors running mine


I also managed to find Derale 15850 for $150 so I think I'll plumb it between the pump and the tank. I think for such a low cost it will help a lot. I had Derale 15300 without the fan on another speedaire 20 gallon 10 cfm compressor, and the difference it made was enormous. I think having a fan in addition to the cooler will help a lot

 

[u3b3rg33k]

these are quite quiet:

Polar Air Silent Air Industrial Plus 5HP 19CFM 1 Ph 2-Stage 80 Gal. Vertical Stationary Electric Air Compressor-W/ Pressure Lube Pump , Isolator Pads, Belt Tensioner, Continuous Run, Auto Drain w/ 30CFM Dryer

eatoncompressor.com

A refrigerated dry gets the air MUCH dryer than using ambient shop temperature and a radiator.

I'm not familiar with either of those, so no comment there. Just size the dryer to match the output of your comp--or a little more.

The dryer between the comp. and the tank is great--IF you have an air-air cooler before it. Otherwise, you're severely over-loading the refrigeration unit of the dryer. Air right out of the comp is HOT.

The refrigerated dryers don't require much maintenance--about the same as your kitchen 'fridge. Keep the condenser coils clean and that's about it. Check that the drain valve is actually opening occasionally--usually a timer setting in the menu of the unit--as a stuck drain valve can overheat the compressor of the unit--I just killed one this way.

Your tools will love you for using a dryer.

FWIW this is why the "high-temp refrigerated dryer" lines exist:



they have a heat exchanger of inlet & outlet air, so the specific heat is passed "around" the refrigeration system. often these will handle 150-180F inlet air.

another benefit is that reheating the outgoing air means it's not at saturation anymore (like air coming off your home AC coil would be) , potentially causing condensation after the dryer.

We've got a high temp dryer at work. in front of it is a water separator and oil coalescer, to keep the dryer clean.

 

[engineer2]

Yes, try to get a hi-temp inlet air dryer so you don't need an aftercooler.
You can find decent used air dryers for sale online. Just research the specs.

 

[Sumboodie]

How about burial of a line?

 

[u3b3rg33k]

These units seem pretty small, and not overly expensive, and a lot less hassle than building copper pipes, radiators etc.

My air compressor is 80 gallon 2 target, 17 cmf at 90 psi.

I'm looking at these 2 dryers, but can't seem to figure out any difference.

DryStream 25 CFM Refrigerated Air Dryer

Refrigerated Dryers cool compressed air by mechanical refrigeration and removes water vapor/condensation by a moisture separator. Condensation is automatically drained reducing maintenance. Dew point Indicator checks the air quality level at a glance. Qui

www.kmstools.com

SMC 110V 25 CFM Refrigerated Dryer

IDF refrigerated air dryer series, in compliance with the Montreal Protocol Regulations, uses refrigerants

www.kmstools.com

Is it just the brand? Is one better than the other? Do these require maintenance? Do you plumb them between air pump and air tank or at air compressor outlet?

I was thinking of building something with a radiator, but considering the time and effort required, maybe this would work better.

https://www.compressorworld.com/categories/6274/refrigerated-air-dryers#filters=f533-1955

filters on for high temp, sort by price.

 

[Torque&Recoil]

How about burial of a line?

I was thinking about that same idea, some time ago. But I had other things to do and never got around to actually doing anything. You'd have to come up with a way to occasionally blow water out of the system. Maybe bury a tank with a drain line at it's bottom. Drain hose comes up to ground level and has a ball valve on it. Open the ball valve to blow out the collected water. It would work better than the air heat exchanger concept, because you could theoretically cool to 58F ground temp instead of (?) 80 or 90F air temp in summer.

The old refrigerator idea would be even better in theory, because you could cool to an even lower temperature and you don't need to dig a hole. The unknown with that idea, is how many BTUs do you need to keep up with your airflow? In other words, does a dorm room fridge have enough cooling power, or would you need a full-size? I'm thinking a little fridge won't be able to keep up. But if you put a transmission cooler inside the freezer section of a full-size fridge and set the thermostat to 33 F... THAT might kick-A.

Anyway, just thoughts for discussion.

 

[dnschmidt]

If you intend to paint cars JUST DO IT. I live in a desert where the RH is seldom above 25% so I really don't need one but any commercial shop would be wise to use one considering the price of automotive paints.