Is the air blowing OUT of the unit HOT?
I have Hoshizaki KM-500MAH air cooled unit and it is producing ice but at a slow pace. I emptied the machine 2 days ago to clean it and it only has the bin half full. The machine was cleaned recently with lime away and is very clean. The ice that is made comes out perfect. The air filter on the unit was missing when I inspected it and tons of dust and such were built up all over inside the unit and on the condenser coils/aluminum "fins". I tried to blow out the dust, vacuum it out and use a small, fine brush (that did no damage the aluminum "fins") and was able to get out a lot of the build up but most of it is seriously stuck in there. I am going to assume the bad air flow is to blame for the slow ice making. Either way, I know this is an issue because not a lot of air is flowing through the coils. A minimal amount of air seems to be actually passing through. My question is, what can I use to clean the aluminum "fins" and condenser coils? The build up appears to be dust, dirt and grease from a restaurant. I was told car brake cleaner is a non-rinse cleaner that would work but am skeptical. Thanks in advance!
Is the air blowing OUT of the unit HOT?
Reduced condenser airflow will definitely cause slow ice making. If there are other issues, they will be hard to see without proper airflow as fell. You need to correct the airflow first. Make sure there is enough space around the condenser inlet and exhaust as well, a very common problem.
Try Viper Aerosol from Refrigeration Technologies. They list list it as safe for all metals. NSF approved for all food process areas. And the best thing there is no pungent odor like other aerosol sprays from other companies.
Aircraft Mechanical Accessories Technician. The Air Force changed the job title to Air Craft Environmental Systems Technician. But I've decided I'll always be a Mech Acc.
I use NuBrite to clean the Hoshi coils successfully. One trick is to slide the machine back a little so its off the bin and that will help some of the chemical not to go into the bin, but of course a lot will still go into the bin. Remove the condenser fan motor first, its only 4 screws and comes out pretty easy. After you spray it with the Nu-Brite / water mix and it foams up, rinse it out for a loooooong time with water hose, until water goes right through the coil.
On a side note, the self-contained scotsmans can be cleaned the same way, but you can actually unscrew the condenser coil and it will slide out from the back of the ice machine so when you wash it the chemicals just fall onto the floor (for the most part.)
Unfortunatly the coil setup on these make them kinda difficult to get clean once they have been neglected and packed up. The viper product is good as are the ones that stink. I would blow the coil out until nothing comes out anymore before I sprayed anything on it. If there is alot of dirt in it it will turn to mud run to the bottom and stack up and prolong the process. What are your cycle times? Hoshizaki has longer cycles the most other manufacturers. Its a 500 lb machine, if it's on a 1000lb bin and they are using it you may be chasing a problem that's not there. The water and ambient temps could push you freeze time up as long as 50 minuts but 30-35 minuts is pretty common.
Thank you so much for your input everybody.
As far as the cycle times go, I know this is a very amateurish question but how do I tell if the machine is in freeze or harvest mode? I do not know how to tell the cycle times.
I will continue to blow out the machine using compressed air, a fine brush and a vacuum until I close the restaurant on Monday when I will be able to use a chemical solution to clean. It will be very difficult for me to use a hose due to the location of the ice machine but if it will be needed to properly clean the coils and fins I will find a way to do so. Thanks again for your help.
If you can get an air wand with a 90 degree tip it will be easier.
Aircraft Mechanical Accessories Technician. The Air Force changed the job title to Air Craft Environmental Systems Technician. But I've decided I'll always be a Mech Acc.
Cycle time is just that. Time from start of freez to start of harvest is your freeze time. Shut machine off for a couple minuts. Turn it back on and listen when it starts. It will be in harvest for I think 90 sec on start up then go into freeze. You will hear the hot gas bypassing, loud hissing, then it will stop when freez cycle starts. Get your times, freez and harvest, then check the chart for that unit. Also will need ambient and water temp. Also if u use chemical and a hose to wash the cond toss all the ice in it or take it out before u start and store in a freezer the clean and sanitize bin when done. Good luck
Cycle time is just that. Time from start of freez to start of harvest is your freeze time. Shut machine off for a couple minuts. Turn it back on and listen when it starts. It will be in harvest for I think 90 sec on start up then go into freeze. You will hear the hot gas bypassing, loud hissing, then it will stop when freez cycle starts. Get your times, freez and harvest, then check the chart for that unit. Also will need ambient and water temp. Also if u use chemical and a hose to wash the cond toss all the ice in it or take it out before u start and store in a freezer the clean and sanitize bin when done. Good luck
Yeah, I was planning on dumping all the ice prior to the cleaning and sanitizing the entire machine afterward a few times. Don't want to mess around with those chemicals.
I will get my harvest and freeze times tomorrow and compare them to the chart in my Hoshizaki manual. I am pretty sure my freeze time will be above the estimated time of about 36 minutes (80-85 degree ambient temp/70-75 degree water). Thanks again for all your help and I will keep you guys updated!
On Hoshi's monitor the water pressure when it goes into harvest. If it drops below 20 psig it may have harvest problems.
Aircraft Mechanical Accessories Technician. The Air Force changed the job title to Air Craft Environmental Systems Technician. But I've decided I'll always be a Mech Acc.
Ok so I used a degreaser and high powered compressor and spent a few hours cleaning out the condenser and aluminum foils. It didn't come out perfect but since I cannot easily use a hose where the machine is located, this was the best option. The airflow is much better through the coils. I did not take the freeze and harvest times prior to the cleaning but afterward they were 34 minute freeze cycle and 3 minute harvest cycle. It is most definitely working much better. The freeze cycle was right on point, maybe even a minute or 2 shorter. The harvest cycle was about 60 seconds longer than it should have been, is this anything of concern?
Another question I had is whether or not you guys recommend a water filter being installed on the unit? As far as the taste goes, the ice if fine. I was just wondering if a water filter would extend the life of the machine or not. Thanks again for all your help!!
I would say if the cond was that dirty your evap is probably pretty nasty as well which can push your harvest long, doesn't release ice properly if scaled up. Yes install a water filter not so much for taste but for scale and such, ever pure makes a good product. Most ref supply houses can hook you up. For now, if you haven't already, clean the water side. Follow the procedure in the manual. I always take it apart and clean then reassemble and run clean cycle. Don't be fooled looking at it wet. If you haven't cleaned it it's dirty. Should approach every ice machine with that mentality. Good luck.
When in a greasy restaurant I use Alka-Brite Plus made by Nu-Calgon. Cuts the grease off ass soon as you apply it. It also does an awesome job foaming out the dirt. Be sure to wash it out the opposite direction of the air flow.
Also per Hoshi when you time the ice production you want to time a complete cycle from the beginning of one freeze cycle to the beginning of the next.