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post-adobeair1.jpgThe whole US is currently experiencing a massive heat wave, but we seem to be getting more than our fair share of it down here in Texas.  The heat in our shop’s been almost unbearable as the outdoor temps have rised to over 100 degrees F every day this week.  (We even hit 106 one day.)  We went in search of a way to take the hurt out of the heat and ended up trying out one of AdobeAir’s Mobile MasterCool series portable evaporative coolers.

Operational Theory 

All coolers work by transferring the energy from the hot air to somewhere else or converting it to some other less-annoying form.  In normal household A/C units, a coolant such as Freon is used in a closed system, sapping the energy from hot inlet air to evaporate the coolant, then releasing the heat outdoors as the coolant re-condenses.

Evaporative coolers — or “swamp” coolers as you may have heard them called — work on the basic principle of cooling by the evaporation of water.  Evaporative coolers are very simple machines.  They consist of a fan which draws hot inlet air through an “evaporative pad” — a piece of porous material which is constantly soaked with water via a pump and reservoir.  Energy is removed from the hot air as it evaporates the water.

As with all coolers, the heat must go somewhere.  Unlike closed-system Freon-based units where the heat is “moved” to another location, evaporative coolers simply blow out the resulting water vapor along with the cooled air.

This leads to the basic limitation of evaporative coolers: the source (inlet) air must be dry enough (low enough in humidity) to allow for evaporation.  If the water in the evaporative pad can’t evaporate, no cooling occurs. 

This means that the more humid the air is around the cooler, the less cooling it’ll provide.  If you live in a very humid area such as Florida or Houston, you’re going to see far less performance from an evaporative cooler than you will if you were to live in, say, Arizona.  It also means that you can’t use an evaporative cooler in a sealed-off environment.  As the cooler operates, it’ll continue to add humidity to the air until the air is too humid to allow evaporation — at which point it’ll cease to cool.

With this in mind, read on to take a look at the MasterCool MMB12 — one of AdobeAir’s mobile “spot” coolers.


post-adobeair2.jpgWe picked up our MMB12 from a big-box home improvement store.  It came mostly assembled in a large box.  (The unit itself measures 26-1/2″ W x 26″ D x 40″ H.)  The wheels were already attached and the filler float system was already installed as was the drain plug in the bottom of the unit.  The only piece remaining for us to install was the plastic drink-holder tray that mounts to the top of the unit.

The MMB12 is designed with the bottom of the unit as a 7.5-gallon water reservoir.  It has a garden-hose fitting near the bottom rear of its base which attaches to an internal float-style regulator that opens when necessary to automatically replenish the reservoir.  The manual indicates that any water pressure up to 100 PSI is OK, and this shouldn’t be a problem for most homes and businesses (which are usually regulated to 75 or 80 PSI).

A pump assembly stands in the bottom of the reservoir and pumps up a clear tube to a black plastic T-fitting at the top of the unit, which directs water to the left and right sides.  Removable metal frames on each side hold AdobeAir’s “premium evaporative pads,” which look like paper or cardboard radiators.  They’re about an inch-and-a-half thick and soak up water quite effectively.  The top of the frames feature an angled metal flange which catches the water from the T-fitting and directs it down a channel at the top of the frame.  Holes in this channel allow it to act as a manifold to direct water across the entire evaporative pad.

post-adobeair3.jpgIn the center of the unit is a caged 5.6A fan which draws air from inside the unit (through the evaporative pads) and exhausts it out the front through a protective grille.  Outside the grille are a series of vertical and horizontal vanes which can be used to direct and channel the cooled air.

A sealed switchbox on the back of the MMB12 holds switches for the pump and the two-speed fan.

In Use

As you can imagine, we were pretty excited to fire up the MMB12 and experience a cooler shop.  We ran into a few problems out of the box, however.

During shipping (or shelving — who knows?) some damage occurred to our unit.  The plastic T-fitting had broken off at the inlet fitting.  We returned the fitting itself to the store we bought it, and after some wailing and gnashing of teeth — they wanted us to return the whole unit as opposed to just the broken piece — they allowed us to swap the piece with a working one from another unit.  We drove back to the shop and installed the unbroken component.

Following the instructions, we attached and pressurized the filler with a garden hose.  We did run into a bit of trouble with the attachment as it wanted to rotate as we screwed the garden hose into the fitting.  This is a problem because the float is directly attached and won’t operate if not set at a flat angle.  This was made a bit more difficult by the fact that the float mechanism isn’t extremely durable and is hard to hold in place during the hose connection without damage.  With much careful work, we managed to get the hose attached, at which point the float worked perfectly and filled the reservoir.  We did adjust the float slightly as at factory setting to would have slightly overfilled the reservoir.

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We then turned on the pump for a few minutes to allow it to pre-soak the evaporative pads before we engaged the fan.  Upon turning on the fan, we did indeed feel some cooler air coming out of the unit.  An HVAC thermometer indicated that it was 98 degrees in the shop, and the air coming out of the unit ranged from 88 to 85 degrees.  This was a bit shy of our expectations set by AdobeAir’s documentation and advertising which indicated that we could expect “sub-80-degree air in most climates” and “up to 30 degrees of cooling.”

So, we started troubleshooting.  Concerned that we might be over-humidifying the air, we opened another roll-up door to allow in additional dry air.  This resulted in little or no change to the output temp.  Secondly, we noticed that one of the evaporative pads wasn’t staying completely wet.  We checked the unit with a level and discovered that that wasn’t the problem.  (You want to keep the unit on level ground as the manifolds that wet the evaporative pads are gravity-fed.)  So, we turned off the pump, ran the fan a bit to dry out the pads, and removed them.  Looking closely at the manifold in the top of the offending pad’s frame, we discovered that the holes near the “dry” end were closed up more than the ones on the “wet” end.  We used a screwdriver to carefully pry open the closed up holes to try and more closely match the ones on the other end.

post-adobeair7.jpgWe then re-assembled the unit and fired it up by the manual’s proceedures.  This time both pads appeared to be uniformly wet, and indeed we saw slightly lower output air temperatures — as low as 82 degrees.  During this time we approached sundown, however, and the temperature in the shop had dropped to 95 degrees, so it’s hard to tell whether or not the unit was responsible for the drop.  Sadly, we have yet to be able to duplicate the company’s claims of sub-80-degree output.  (Note: During the days we were testing, weather.com reported less than 35% humidity at our location.)

Of course, let’s be clear that we’re not complaining too much about 82-85 degree air.  This feels downright frigid when you’re standing in a 98 degree shop, and does make a difference.  The manual suggests using the low fan speed setting for maximum cooling, which is what we did.  On the high setting output temperatures barely dropped below 90 degrees.

By placing the MMB12 near the specific area of the shop in which we were working, we were able to make the “spot” a bit more bearable.  The vanes on the front of the unit are very helpful, and we adjusted them quite a bit to keep the air directed to our workspace. 

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You do have to be careful when moving the MMB12 because the level of water in the reservoir reaches very close to the vent holes, meaning that if you move it too quickly water’ll slosh out the sides.  You also must keep the MMB12 level during the whole moving procedure.  If you want to roll it up an inclide or lift it over a bump you have to shut off the fill hose and drain the reservoir first.


Our experiences with the MasterCool MMB12 didn’t match those portrayed in the marketing literature, but we still seem to find it a useful addition to the shop.  Even a 10-15 degree cooling in the spot we’re working in makes a difference in the Texas heat, and we’re glad to have it.

We’re very skeptical of AdobeAir’s claim that the MMB12 will cool a 1000 sq. ft. area.  Even taking into account the fact that the area in which we placed the unit has a 10′ ceiling (as opposed to the 8′ accounted for in the company’s numbers), we never saw the unit make a significant dent in the overall temperature in our 680 sq. ft. room.

It’s important to note that this isn’t a carefree unit to operate.  You need to be prepared to set it up about 15 minutes before you want it running, and you’ll need to plan in 15 minutes or so to shut it down — more if you’re not going to use it the next day and plan on draining the reservoir.  You’ll also need to make sure you have a water source (or a long hose) and power available where you want to use it and a level place to set it.

It’s also not cheap.  Our unit sold for $397.00, and by the time you add a hose, a few plumbing fittings, and tax to that it ends up falling on the high-side of the $450 range.

That said, we definitely fall within those requirements, and we’re more than willing to pay the dough to stay cool.  Though we were a bit disappointed with the unit’s performance, we chose to keep it rather than return it; We just need the cooling that bad. 

As we own the unit, we’ll report back later on our longer-term experiences, including regular maintenance and any issues we might have.  We did contact AdobeAir, and they indicated that we might be able to get more performance from the unit.  They intend to have an engineer contact us, but we haven’t heard back from them yet.  If we learn more during those conversations, we’ll pass the information on to you.

Other Units from AdobeAir

AdobeAir offers two other units in the MasterCool line, one larger than the MMB12 and one smaller.  They also offer a wide variety of non-portable units, all of which are listed along with performance numbers on their website.

MasterCool Commercial High Velocity Blower Wheel Mobile Coolers [AdobeAir]


16 Responses to Hands-On: The AdobeAir Mobile MasterCool MMB12

  1. jim porterie says:

    I bought my MMB-12 April a year ago. I have it in my garage. I have it because I have a 25 cu refrigerator and a large freezer in the garage. It cools well enough the the area is not to warm. I live about 25 Miles so of Phoenix our summer temp runs up to 118. Most days about 106. I feel the cooler saves enough power keeping the ref and freezer at about 89 degrees. I had another unit for the eight years before and it didn’t work as well. I drain the unit every 4 days as our water is very very hard. I took the pads out and cleaned them and reversed them this year. They are hard to get in to and replace. I payed about the same as you and am well satisfied with the unit. I will have to buy pads next year I think that will be a large expense.

    Regards, Jim

  2. Eileen says:

    This was incredibly helpful, as I was seriously considering purchasing this. Thanks for all the detail.

  3. Thad says:

    I have a neighbor with this same unit. After 5 minutes of operation, his living room was nice and cool even when the outside temps were still around 90, and I’ve been considering a purchase ever since.
    I appreciate that you took the time to give extra information on the setup and such, so that I will know what I am getting myself into.
    Since I live in Nevada, I expect that I will see a bit better results as our humidity here rarely climbs above 20% unless we are getting thunderstorms and rain.

    If I remember, I’ll post back with my experiences as well!

  4. LucyMay says:

    I have the MasterCool MMB12 in my living room with a 5 gallon bucket on top with a hose fitting so I can refill the unit without taking the pad ‘door’ off. Works fine if there are enough windows open. Do I need to oil anything? Any suggetions regarding excessive salt build up? I live in Peoria, AZ. Can I run the unit with added vinegar to deal with the salt? Thanks!

  5. Bruck says:

    Here is the deal-

    You must remove the paper pads that the unit came with & get some old fashioned Aspen pads. Get some 2X the size needed & double them up. Cram them in & be sure the top edge of the pad is positioned so the inrushing air does not make the water pull away from the pad. Don’t take my word for it, try it for yourself. Aspen pads work because the fiber of the natural wood holds many times more water than artificial media can. You WILL see better performance. Despite the claims of the “new” pad manufacturers natural old-fashion Aspen is superior.

  6. Mitch says:

    I had the mmb12 from lowes ($300) for about 3 years. The motor died on it and I cannot find a replacement.
    Anyways, we definitely saw a 20 degree drop in temperature.
    The trick is to run the unit outside and let it pull in fresh dry air which we have plenty of in nevada. Put the unit into a slit in a window and then open a window on the far side of the house or one upstairs.
    I respectfully disagree that the rigid media is less effective than the wood. Evaporative cooling relies on evaporation from the surface of the media so absorption is not desired. The rigid media has more surface area from which to evaporate.

  7. Steve says:

    Bought the model MMB12B Mobile Mastercool six years ago for my garage. After reading the users guide found out that you have to replace the filters every 3 years or so. And they can be expensive. Why, I don’t know because they are just cardboard. Called Adobe Air in Phoenix. Waste of time.

  8. lisa says:

    Can it run on water the reservoir alone with refills or does it need to alway be connected to a hose/water source to keep running?
    Also, has anyone used Aspen pads in this instead of the filters it comes with?


  9. Larry says:

    i have this the moter bure out from the water getting on it fron the pad when i get a new moter i name a shild to put over the moter site to keep the water off it i lost the low speed it still wark on high but it failed to so now i looking for a moter but it good to have around what you working out side in a car or van i use to the blow air in the door of the van of car im working on out in the sun and it make it a lot better

    i fine a new for $230.00 from Adobe Air


    here the link if you need parts

  10. Jimmy says:

    I think if you supplied dry, outside air, at all times, and vented the humid air inside the garage out through small open areas (cracked windows and cracked doors), you would see better performance. You never want to feed humid air into the system. Otherwise, your shop will get too humid and cooling will stop.

    The best thing to do with one of these is to mount it in a wall opening of some sort with a thermostat, power, and water supply. Would work great in room of the correct square footage.

    Sounds like it was a success, overall.

  11. George says:

    The motor burned out on mine because it is mounted inside the cage and is constantly exposed to water vapor. The new motor was insanely priced, especially considering I would probably only get one season from it like the last one. For less than the price of the motor I mounted the squirrel cage on a 1/2 inch rod and mounted the rod with bearings like a typical cooler. I then mounted a standard cooler motor on top of the unit and used a belt to drive the fan (squirrel cage). I had to cut a slot in top of the unit for the drive belt. The motor should last many years because it is no longer exposed to water.

  12. Ed says:

    I’ve had one of these for three years now. It has worked fine as a cooler and now I am getting good use from it as a humidifier during the winter. I have not hooked up the hose. I fill it manually, thus I know we are putting twenty to twenty-five gallons into a three thousand sq. ft. house every day. Humidity levels have gone from sixteen percent to forty percent, saving the glue joints of our furniture and guitars.

  13. Samuel says:

    I have my machine but actually still don’t know how to operate can someone help me with a video

  14. Jerold Hunter says:


    • Pablo A Torre-Walter says:

      Hey there, I really doubt you’re still interested but in case you are I have one available and we can negotiate price

  15. fckoffndyeit says:

    I know this post is old. The machine is discontinued, but I Still have mine. Couple tips with swamp cooling, if you want the cool air to travel to the opposite end of the building, crack a window in the area you want it to go. Much like non-central air, if you close off rooms you aren’t using, (windows, too) it will cool more efficiently. The motor has a lubricant hole you’re supposed to put motor oil in.. Just a few drops. Otherwise, telescoping oil for the shaft and “spinny” parts. If you don’t oil the motor, it will burn out quickly. If water is spraying your motor, they are somewhat tolerant, but clamp your pump hose down a bit. Same if its spewing droplets out the front. Too much of a good thing is no bueno. If limescale and calcium are present in your water like mine, a bleed off valve in the middle of the pump line ran through the drain plug will keep the water fresher and less chance for the scale to build. Also a bar of lava soap, salt and a calcium filter will help. Salt is corrosive on metal, so make sure the inside is well sealed with marine paint/tar sealant or try the other options first. And if you want your house to smell nice, pour a little of your favorite scent into it. Febreeze, fabric softener, diffuser oil… start small. If it rusts, seal it with the cooler sealer. Sand the rust off first and hopefully slow the rot process. It’s part tar, like asphalt, and will have that smell at first but I have managed to get a few extra years out of a second hand cooler that already had rust HOLES in it with these tips. I fully service them at the beginning of the season and don’t have to touch them till the end if I do it right. Sometimes fine tuning is necessary.
    Now there are these rad window units that are slim in design and more efficient, but 3-4 times the price of these little guys. Sounds lovely, though. I’d like my side door back. 😏
    By the way, you can build one of these for next to nothing using a 5 gallon bucket, cooler pad media, fish tank tubing and a tubing tee, an aquarium pump or small pond pump (maybe 50 gph) a small fan and some dryer ducting. Solar power it when camping. I have yet to build one, but will be this month. Pretty stoked to try!

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