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Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Michelle on September 06, 2015, 04:22:50 pm

Title: Traveling Man's HWH Desiccant question
Post by: Michelle on September 06, 2015, 04:22:50 pm
I'm trying to find out what is the best cure for bead replacement all the time, ie: a bigger filter?

Move to a dry climate  :giggle:

I think we replace ours about once a month under "normal" conditions, sometimes less often if we're in one place for a while and it's not humid.  Kind of did a "one time buy" on some indicating desiccant and mylar bags from Sorbent Systems and "rolled my own" for a tiny fraction of the usual cost (like $2.50/4 ounce bag compared to something like $20-50 bucks per 4 ounce dose).  I did a post on it a few years back.  Note that you can re-dry the spent stuff and reuse it.

ETA - found my old (4 years ago!) "Instructable" Desiccant option for the HWH system (http://www.foreforums.com/index.php?topic=12784.0)
Title: Re: Traveling Man's HWH Desiccant question
Post by: Tom Lang on September 07, 2015, 12:02:59 am
Move to a dry climate  :giggle:

I think we replace ours about once a month under "normal" conditions, sometimes less often if we're in one place for a while and it's not humid.  Kind of did a "one time buy" on some indicating desiccant and mylar bags from Sorbent Systems and "rolled my own" for a tiny fraction of the usual cost (like $2.50/4 ounce bag compared to something like $20-50 bucks per 4 ounce dose).  I did a post on it a few years back.  Note that you can re-dry the spent stuff and reuse it.

ETA - found my old (4 years ago!) "Instructable" Desiccant option for the HWH system (http://www.foreforums.com/index.php?topic=12784.0)

I bought the same desiccant.  Since I need change mine every couple of years, my purchase should last a couple of lifetimes. I live in Los Angeles.  A very dry climate.

By the way, I plan to be in Quartzsite come January, I'll  be happy to share some of my excess desiccant.

Title: Re: Traveling Man's HWH Desiccant question
Post by: Barry Beam on September 07, 2015, 02:17:37 pm
Also will install pressure gauges on everything as Barry suggested.  Big deal is the desiccant filter and replacement of the beads.  I'm trying to find out what is the best cure for bead replacement all the time, ie: a bigger filter?
After talking to James Triana about this same thing, He suggested removing the desiccant bowl altogether. They no longer put them in the new coaches. It is inadequate. I find I have to replace or rejuvenate the beads every couple of weeks which does not get done a lot of times. They also no longer add the rocker switch on the drivers dash panel to allow you to fill the Front and Rear tanks in the AM before leaving so you do not have to idle long. Which can put moisture in that system. The Aux compressor is to small for that.
Another thing I learned was that after replacing my Air Dryer Kit in Canada I was still getting moisture out of the front and rear tanks. Now they tell me that is normal when you are in high humidity which I am not when home in SoCal.  Just have to bleed the tanks after I park.
Title: Re: Traveling Man's HWH Desiccant question
Post by: wolfe10 on September 07, 2015, 04:59:05 pm

Another thing I learned was that after replacing my Air Dryer Kit in Canada I was still getting moisture out of the front and rear tanks. Now they tell me that is normal when you are in high humidity which I am not when home in SoCal.  Just have to bleed the tanks after I park.

Barry,

Not sure I am going to buy that it is normal to get water out of the tanks with a properly functioning dryer.  Never happened to us, and we live right on the gulf coast.
Title: Re: Traveling Man's HWH Desiccant question
Post by: jtm2014 on September 07, 2015, 05:23:32 pm

  I followed Michelle's post on "bagging" my own desiccant and find I need to cook the desiccant every month or
 so and replace it twice yearly.  Bagging your own is not hard and saves some money.
Title: Re: Traveling Man's HWH Desiccant question
Post by: Barry Beam on September 07, 2015, 06:24:56 pm
Barry,
Not sure I am going to buy that it is normal to get water out of the tanks with a properly functioning dryer.  Never happened to us, and we live right on the gulf coast.
I am looking for a better answer. I replaced the Air Dryer kit but i was still getting moisture from front tanks but not wet tank. Now that i am home I am not getting the moisture. I can't see anything else that is in the system to cause it. I was always told when you see moisture it is time to change filter but it did not help. I can't get any better answer from the factory. Any suggestions?
Title: Re: Traveling Man's HWH Desiccant question
Post by: Michelle on September 07, 2015, 07:06:17 pm
I replaced the Air Dryer kit but i was still getting moisture from front tanks but not wet tank. Now that i am home I am not getting the moisture. I can't see anything else that is in the system to cause it.

Could be the check valve in the line from aux compressor to front tanks inline with solenoid controlled by "air tank" crossover switch or that solenoid valve leaking through.

Watch A/B tank pressures (ignition to accessory, but don't start the Cummins) on the Driver Info Center when aux compressor is running with "air tank" crossover switch off - if they rise at all there's probably  leak through.

In humid climates where you're overwhelming the aux compressor desiccant (and the aux compressor is running more than normal because air is also pushing into the A/B tanks), there's where moisture could be coming from.

Did you also replace the heater in the air dryer?  It's not part of either service kit but would be new in a factory-remanufactured dryer.  I would suspect it plays a role in air dryer efficiency/effectiveness.
Title: Re: Traveling Man's HWH Desiccant question
Post by: Tom Lang on September 08, 2015, 12:53:58 am
After talking to James Triana about this same thing, He suggested removing the desiccant bowl altogether. They no longer put them in the new coaches. It is inadequate. I find I have to replace or rejuvenate the beads every couple of weeks which does not get done a lot of times. They also no longer add the rocker switch on the drivers dash panel to allow you to fill the Front and Rear tanks in the AM before leaving so you do not have to idle long. Which can put moisture in that system. The Aux compressor is to small for that.
Another thing I learned was that after replacing my Air Dryer Kit in Canada I was still getting moisture out of the front and rear tanks. Now they tell me that is normal when you are in high humidity which I am not when home in SoCal.  Just have to bleed the tanks after I park.

Are you suggesting removal of the bowl, or just keeping it empty of desiccant?
Title: Re: Traveling Man's HWH Desiccant question
Post by: Barry Beam on September 08, 2015, 10:51:35 am
Are you suggesting removal of the bowl, or just keeping it empty of desiccant?
Removing the bowl altogether.
Title: Re: Traveling Man's HWH Desiccant question
Post by: Don & Tys on September 08, 2015, 11:25:53 am
Barry,
It seems to me that if the desiccant beads are getting used up, then they are performing a valuable service to keep moisture out of the system, at least from the aux compressor side of it. I would think that the answer would be to get a dryer/filter with more capacity and insure that any other sources of moisture are addressed. I plan on adding the switch for wet tank pre-filling and and this unit: Amazon.com: DeVilbiss 130525 QC3 Air Filter and Dryer: Automotive (http://www.amazon.com/DeVilbiss-130525-QC3-Filter-Dryer/dp/B002PR8ZXK)
The refills are fairly expensive, so it won't be as economical to use, but it will be easy to change out the cartridge when the time comes. I am hoping that it lasts long enough in our application to make it fairly painless...the only difficulty in installation is that they say it should be 25' away from the compressor! I read this as mounting it so that the air cools and moisture condenses before reaching the filter and so I will run a loop on air line, maybe 6' to 8' before the filter unless I can figure out a place to mount it that far away and still make the cartridge easily accessible and viewable.
Don
I am looking for a better answer. I replaced the Air Dryer kit but i was still getting moisture from front tanks but not wet tank. Now that i am home I am not getting the moisture. I can't see anything else that is in the system to cause it. I was always told when you see moisture it is time to change filter but it did not help. I can't get any better answer from the factory. Any suggestions?
Title: Re: Traveling Man's HWH Desiccant question
Post by: David Bethard on September 08, 2015, 02:35:13 pm
One 5 pound can of desiccant lasts virtually forever in the HWH dryer. I bag the used stuff and cook it in the oven when I get enough, then reuse it. That little compressor really beats the moisture out of the air. If the compressor runs very much it will load up the beads in short order along the Gulf Coast. Once the desiccant gets damp the metal parts in the filter corrode quickly. Without the desiccant package that moisture stays in the system, I'd rather get it out.

Bulk Sorbents - sorbentsystems.com (http://www.sorbentsystems.com/bulksorbents.html)

I live on the Texas Gulf Coast and never get water out of either dry tank and don't recall ever getting any out of the wet tank. I believe the heater on the air dryer is only to prevent freeze up's in cold weather, not part of the regeneration process. I believe the dryer is self regenerating but that's not to say it shouldn't be serviced. Recommended yearly but I usually go two years between service. When the dryer blows down (purge valve opens) captured moisture in the desiccant is released as the air exhausts out the bottom of the dryer. If the dryer is not blowing down as pressure builds it can't get rid of moisture and will become saturated. When I replace the filter/desiccant I replace the seals in purge valve. It's almost as cheap to replace the whole dryer assembly as it is to purchase all the parts to rebuild it.

Haldex DQ6020 Lower Housing Repair Kit for Pure Air Plus Air Dryers:... (http://www.anythingtruck.com/product/070-DQ6020.html)

Midland/Haldex Pure Air Plus Air Dryers: AnythingTruck.com, Truck & Trailer... (http://www.anythingtruck.com/category/htp-brake-air-dryers-pureairplus.html)
Title: Re: Traveling Man's HWH Desiccant question
Post by: Travelin' Man (RIP) on September 10, 2015, 06:05:51 pm
Blue Indicating Silica Gel Beads - 3-5mm - Per Pound - SilicaGelPackets.com (http://www.silicagelpackets.com/loose-bulk-blue-indicating-silica-gel-desiccant-3-5-mm-beads-moisture-absorber-55.html)

I think the compressor is very important to the water-tight integrity of the coach.
What if it fails to deflate the bladder and the slide is out?
What if it fails to inflate the bladder and the slide is in.................and rain is coming?

The compressor has a lot going on with it, offering many opportunities for failure, so as a first line of
defense I'm going to buy some blue beads on Monday.  I don't want to have to replace another floor.
Title: Re: Traveling Man's HWH Desiccant question
Post by: Michelle on September 10, 2015, 07:19:48 pm
Blue Indicating Silica Gel Beads - 3-5mm - Per Pound - SilicaGelPackets.com (http://www.silicagelpackets.com/loose-bulk-blue-indicating-silica-gel-desiccant-3-5-mm-beads-moisture-absorber-55.html)

3-5 is a little larger than what we use (2-4 mm) Bulk Sorbents - sorbentsystems.com (http://www.sorbentsystems.com/bulksorbents.html) .  You might find you'll fit less weight in the bowl and may or may not have to change it more often.
Title: Re: Traveling Man's HWH Desiccant question
Post by: Travelin' Man (RIP) on September 10, 2015, 08:11:48 pm
Do you bag them in 4 oz packets?

And maybe I should have said;
I think the compressor is very important to the water-tight integrity of the coach.
What do I do if it fails to deflate the bladder and the slide is out?
What do I do if it fails to inflate the bladder and the slide is in.................and rain is coming?

Please school me.
Title: Re: Traveling Man's HWH Desiccant question
Post by: Michelle on September 10, 2015, 08:28:04 pm

Yep.  Bought the mylar zip bags that you have to heat seal (Foodsaver), put 4 ounces per bag.  There's usually a little (maybe a couple of teaspoons?) leftover after filling the desiccant bowl - better too much per bag than too little.

That's actually the way the desiccant is sold by FOT (4 ounces/sealed back).  For about $50/4 ounce bag last time we had to buy it there (I believe you can buy it as 3 packs for $50 from Grainger), which was several years ago.  You should have see my eyes when a tech unscrewed our bowl and dumped the spent desiccant into the garbage without asking  :o  :headwall:  Steve could barely keep the language PG rated "what the **** are you doing?  Parts has that stuff priced like gold!"  That was the incident that inspired us to find and bag our own desiccant and we were amazed how cheap the stuff was if you do it yourself.
Title: Re: Traveling Man's HWH Desiccant question
Post by: Travelin' Man (RIP) on September 10, 2015, 08:41:39 pm
Yep.  Bought the mylar zip bags that you have to heat seal (Foodsaver), put 4 ounces per bag.  There's usually a little (maybe a couple of teaspoons?) leftover after filling the desiccant bowl - better too much per bag than too little.

What size mylar bag 3" X 5.5"?
Title: Re: Traveling Man's HWH Desiccant question
Post by: Michelle on September 10, 2015, 08:43:33 pm

Cheapest they've got that aren't too big or small.  I think ours are 5" x 5.5" but I will check in the AM-ski.  3" x 5.5" should work fine but I would like to verify first.
Title: Re: Traveling Man's HWH Desiccant question
Post by: Travelin' Man (RIP) on September 10, 2015, 08:45:36 pm
Appreciate ya.

What I will do is pour the used desiccant into something that will duplicate the volume rather than the weight
and maybe not waste any "blue gold".

I may get this for $19.49 for 5lbs delivered;
Orange Indicating Silica Gel Beads - 2-4mm - DesiccantPackets.com (http://www.desiccantpackets.com/pounds-loose-bulk-orange-indicating-silica-gel-desiccant-2-4-mm-beads-moisture-absorber-dehumidifier.html)

Don, how about one of these?
Speedaire Dryer, Desiccant 5VC89 | Zoro.com (http://www.zoro.com/speedaire-dryer-desiccant-5vc89/i/G1141935/?utm_source=Bing&utm_medium=cpc&utm_campaign=PLA)
Title: Re: Traveling Man's HWH Desiccant question
Post by: Michelle on September 11, 2015, 09:05:17 am
What i will do is pour the used desiccant into something that will duplicate the volume rather than the weight
and maybe not waste any "blue gold".

I may get this for $19.49 for 5lbs delivered;
Orange Indicating Silica Gel Beads - 2-4mm - DesiccantPackets.com (http://www.desiccantpackets.com/pounds-loose-bulk-orange-indicating-silica-gel-desiccant-2-4-mm-beads-moisture-absorber-dehumidifier.html)

We keep a heavy duty zip bag (freezer kind) for spent desiccant and dump any extra (again, it's just a couple of teaspoons) into that bag.  Eventually we'll regenerate it and repack the bags.

Dean and Dee used the same orange silica beads from Sorbent - no cobalt so more "green" than the pink/blue.  Bulk Sorbents - sorbentsystems.com (http://sorbentsystems.com/bulksorbents.html)  Just put a sticker on the desiccant bowl noting the different fresh/spent colors for future reference.  It wasn't available when we bought ours, we have the 2% blue mix ($21.80/can at Sorbent)

Our bags measure 5.5 x 5.25 inches and are the open zipper-end style, which I don't currently see on Sorbent's site (they were on special when we bought them; no special reason for that size).  If you've already got a Foodsaver or cheap hair styling flat iron (as Dean and Dee used) you could go with the high volume 3.5" x 6.75" special they have at half the price of the other bags ($25/100) 035MFS0675ZTE.

For just under $45 you'll be able to make 20 4-ounce packs of desiccant (and have many spare bags left over), versus $50 for one pack.  OK, maybe $60 if you have to buy a cheap hair iron...
Title: Re: Traveling Man's HWH Desiccant question
Post by: Michelle on September 11, 2015, 10:33:34 am

What do I do if it fails to deflate the bladder and the slide is out?

Round, closed-cell cross-section foam weatherstripping from HD/Lowes stuffed in the gap from the outside.

Quote
What do I do if it fails to inflate the bladder and the slide is in.................and rain is coming?


Low-tack duct tape applied on the outside, across the gap.

In either case, make sure valves for slide bladder are closed (and replace with ball valves for better reliability) when you don't need to move the slide.  You can "fake out" the controller into thinking vacuum has been achieved when you need to "deflate" a failed bladder to move the slide.

Been there, done that with a slide bladder failure.  Emergency '03 slide bladder repair (http://www.foreforums.com/index.php?topic=10319.0)



BTW - if you edit a previous post, it's not obvious you've added content (it doesn't show up as "new" again).  It's usually best for visibility to just add a new reply to the thread.
Title: Re: Traveling Man's HWH Desiccant question
Post by: Travelin' Man (RIP) on September 12, 2015, 10:15:59 am
Regarding your '03 emergency slide bladder repair....................I  use Super Glue to bond rubber to itself, and believe me it will
keep a tire patch on with only 12lbs of air  pressure behind it.
Title: Re: Traveling Man's HWH Desiccant question
Post by: Dick S on September 29, 2015, 10:16:21 pm
Jim McNeese installed a larger capacity desiccant filter. Maybe he will comment. I have been wanting to do the same. Dick
Title: Re: Traveling Man's HWH Desiccant question
Post by: speedbird1 on September 30, 2015, 10:08:34 am
Call me dim if you wish, but where the heck do i find this dryer and Silica gel bowl on my 2001 U320?? I am obviously a dollar short and several years too late??
I never get any moisture out of the drains on the back Left side or from the tanks under the front I guess as we live in an area of very low humidity (average around 20% or less).
I don't seem to have an auxiliary compressor like the old Grand Villa had, noisy thing??
Live and learn every day!!! Please educate me.
Brian.
Title: Re: Traveling Man's HWH Desiccant question
Post by: sam7 on September 30, 2015, 11:52:26 am
Brian, I have a 2001 U320 also. We do not use desiccant in our slide system, so quit looking LOL.
Title: Re: Traveling Man's HWH Desiccant question
Post by: speedbird1 on September 30, 2015, 12:21:32 pm
Hi Sam,
Many thanks.  I thought I knew a lot about our coach, and then this comes up so much head scratching!!  I could also have been asleep when they gave me the class at FT??
So I guess we don't have an electric air compressor either??
Brian.
Title: Re: Traveling Man's HWH Desiccant question
Post by: Michelle on September 30, 2015, 01:07:09 pm

So I guess we don't have an electric air compressor either??


Look for something that looks like what Fiddler has  Electric motor runs often in main bay... (http://www.foreforums.com/index.php?topic=26149.msg208802#msg208802)
Title: Re: Traveling Man's HWH Desiccant question
Post by: speedbird1 on September 30, 2015, 01:19:05 pm
OK Michelle,
I will go and look, but I have never heard it unless it is a super quiet one.  I remember that the old coach had a real noisy one.
Brian.
Title: Re: Traveling Man's HWH Desiccant question
Post by: sam7 on September 30, 2015, 04:15:10 pm
Brian, your compressor is located on the drivers side in the big storage compartment up high. I don't hear mine either, but then I don't hear very well so all is good.
Title: Re: Traveling Man's HWH Desiccant question
Post by: speedbird1 on September 30, 2015, 06:51:46 pm
Thank you folks,
I found it just where you said it would be!!  It has a switch on the frame and what appears to be an in-line fuse??  At present I can't actually get in there, but will let you know when I can.  Three possibilities, the in-line fuse, my deaf ears, or it is broke!!
Brian.