Hydro-Hot air flow

[Basil Shannon]

From Thread on Hydro-Hot access: "Renipladlo............Alpines in my opinion are the worst ........And although not part of this post, the cozy air handlers for the hot air to be delivered were the worst install of the whole thing. Some owners report no hot air coming from them because WRV used "dryer type hose" for those heat delivery lines. AQ/HH school recommends no more than 270 degrees of bends in the air delivery lines, and every hill & valley of that hose is considered a bend. By the time it goes 1 foot, the air is almost dead for flow. I have replaced all the ones in our coach except the front one (under dash) & shower-WC, now we have such good heat from those we have to turn down the thermostat. I am still working on a solution for the one in the bathroom and front."

Renipladlo, I took your comments from the other thread and opened a new one. I know this has come up before but I thought I would turn over the rock one more time.

Looking at the HH installation Manual http://www.aquahot.com/eSource/ecom/...l06-02_000.pdf
The fans on the Cozy air handlers are small (computer fans?) and put out a relatively small ammount of air. In an ideal installation (see manual), the Cozy air handlers are butted up against the outlet register and blow directly into the room. In the real world, this is not always possible and hoses are required. WRV did not always make the best choices in the location of the air handlers. Some of this may not apply to every coach.
FRONT: The air handler is mounted on the passenger side of the forward firewall and hoses run out the bottom of the center console. Without a major redesign, I don't know what else they could have done. Air flow is minimal.

LIVING ROOM: Most air handlers are mounted under the jack knife bed and close to the outlet. Airflow ok? With my hide a bed equiped coach, there is about a 3' hose to the forward end of the couch and airflow is minimal.

KITCHEN: On my coach, the air handler is located under in the kitchen cabinet under the drawers aft of the kitchen and seems to work well.

BATHROOM: On my coach, the air handler is located forward of the toilet behind the breaker panel. The toilet therefore is toasty warm. The other half of the air handler is ducted thru the floor into the basement, approx 5' to the back of the tank bay, approx 5' to the other side of the coach and another 5' forward and back thru the floor under the shower. DUMB!!! If the little fan was able to push air that far, all of the heat would be disapated into the cold basement. I fondly remember my propane heated coaches actually put out heat from under the shower and made the shower floor warm. I wonder if I can reroute this duct into the hallway adjacent to the CB panel.

BEDROOM: The air handler on my coach is located under the bed with two outputs and seems to work well. On some other coaches, I understand it was located under the closet and ducted 8-10' under the bed and out. Not good!

RETURN (MAKEUP) AIR: The manual says that there should be a opening providing return air equal to the size of the outlet register.
FRONT: Sufficient air probably comes in from under the dash.
LIVING ROOM: Sufficient air probably comes in from behind the couch.
KITCHEN: Sufficient air probably comes in from under the slide and at the aft end of the slide.
BATHROOM: In my case, I am not sure what openings there are.
BEDROOM: There seems to be a need to cut a return air opening which some owners have done.

INSULATION OF AIR HANDLERS: Ever notice how warm it is when you open the kitchen drawers? I put foam insulation on some of my air handlers.

AIR DUCTS: There is a need to keep the length of the air ducts to an absolute minimum. In some cases this would require extending the plumbing and moving the air handlers. Renipladlo: You changed the "dryer type hose" to something else. WHAT? INSULATED?

Ideas? Pictures?

[Wayne R]

I have been thinking about using smooth bore flexible ducting such as Kanaflex. My bedroom area needs some help. I have the the bathroom heat exchanger that is below the drawer of the rear closet. It may be worth moving the heat exchanger to under the bathroom sink.

[bdpreece]

Basil, if you did not run into old RV'r (Monty) in Palm Springs you missed out as he was at TT Palm Springs until early this week. He should now be in Ehrenberg but will be at the the Alpine Rally in Q. He is a factory trained HH tech but is not listed on their site due to the fact that they require him to stock more parts than he can afford to carry in his coach. If you are going to the rally you may want to look him up.

[Renipladlo]

Basil, I sincerely hope you are going to be at DRR. We are, and I will show off what I have done in the HH area to anyone who wants to see it. The cozy units -like the other two options -are a compromise against high amp dray (12V system) versus high air flow. You can look at the other two options I think on HH website. If not do a search on the air handlers themselves. And yes, the dash is warm to the touch, and the kitchen counter is still warm, as I have some air loss because of the box under the kitchen. I did not want to ruin the cabinets taking this out, and plumbing directly out.

Front - Took off the panel and as you say, all those wires, and other tubes for the dash air almost precludes doing anything. I am still kicking this one around, and if I could get some very flexible smooth bore 2" pipe, that would be my choice to replace those line in that location. I purchased some “pond tubing” but its way too stiff, almost like the stuff WRV used in the kitchen slide. It puts pressure on the vent pipe where it meets it, so one day it will crack. I am trying to figure out how/what to replace it with before it breaks the vent pipe.

Couch – I took out the flexible hose here, and replaced it with 200PSI 2” White PVC pipe. I did not need to offset it over once I had done it, so I am going to redo this one once we are home. I get very good air flow out of this location.

Kitchen – because we have the Mid-Door, we have a weird kitchen, that cozy unit is in behind a drawer bank at the rear of the kitchen. Because it’s in the slide, I did not want to mess with moving the cozy unit and maybe causing more trouble. I also had to use a little bit of the ribbed pipe, and stuck the PVC into that, then built a different delivery system from that point. This one is not as good as it could be, and again, if I can get some decent smooth 2” flexible pipe, I will change it out again. The smooth bore pipe must have some rigidity to it, but not too much. The 2” PVC improved the air flow, but it’s not a pretty looking redesign.

Bathroom – Have not figured out how to change this one over. First getting to the Cozy unit, means removing all the circuit panels, and the bottom of the cabinet under the sink. The flow out of the shower is ok and just designed to keep it from freezing in its present form. The line over to the WC area is a joke, no air flow, and at a guess, it’s must be close to 15’ long. There is no flow in the WC area; we leave the door open to encourage any heat from the rear of the coach to get into that area.

Bedroom – My Cozy unit is under the drawer bank on the driver side, and its way down below those drawers. I could not get to it, so I removed the mattress, and the bed platform, and used the same pipe as above to get into those lines. I pushed the pipe well into the flexible hose as far as I thought it would go safely toward the cozy unit, and then re-built the lines out from that point to improve the heat delivery. It is much better, but not perfect. We also installed a vent in the closet so the unit breaths better, or you can leave a drawer open a tad, but then I end up running into it in the night.

To mate up to the cozy units, I kept the little plastic fittings they have (should have had a threaded connection on the units-instead of the hokey twist and lock type). Over those pieces I used a rubber pipe connector with two radiator clamps on it, which clamps it to the Cozy fittings and also clamps to the 2” PVC. All the other connections are glued except where it terminates at the little movable round vents in the bedroom. Dale G took some tool and cut out the ends of the round vents so the output pipe size is the same size as the round vent connection. I did not do that as I did not have my dremel tool to cut the opening as wide as the pipe, and then it would be even better.

As everyone should know, the electric element only rated about 5KW, the diesel unit does 50K BTU, so it’s obvious which source of heat should be used if it’s real cold outside. However we have kept the coach warm enough at night using the electric element down into the low 50’s/high 40’s. Since my exhaust bracket is messed up, and we smell diesel exhaust when we use it and I cannot fix it until I can figure out how to climb under it not get killed in the process. Once it’s fixed, then I can use the diesel burner when it gets cold. My description may not be clear, so it helps if you see it in person.

Basil - If you’re not coming to DRR, let me know, I will take some pictures and e-mail them to you, send me a PM with your e-mail address.

Wayne - Their should be a Cozy unit under the bathroom sink already. There is a vent directly under the shower, and one in the WC. In ours the unit is below the power circuit/inverter circuit breaker panels. Big job to get into that unit, and I might not be able to reach down to it and change anything.

[Wayne R]

Wayne - Their should be a Cozy unit under the bathroom sink already. There is a vent directly under the shower, and one in the WC. In ours the unit is below the power circuit/inverter circuit breaker panels. Big job to get into that unit, and I might not be able to reach down to it and change anything.[/QUOTE]


Old,

My bathroom is heated by a long flexable hose from underneath the rear closet drawers the duct even goes under the coach above the rear axle. Same with the shower area.

The coozy unit under the bed heats the bedroom.

[Basil Shannon]

OLD: "As everyone should know, the electric element only rated about 5KW, the diesel unit does 50K BTU, so it’s obvious which source of heat should be used if it’s real cold outside. However we have kept the coach warm enough at night using the electric element down into the low 50’s/high 40’s."

Actually, the electric element is only 1650 watts according to the manual. It provides adequate hot water for a good hot shower if the incoming water isn't too cold or you're not competing with the washer/dryer or dishwasher. Lyle & Cathy Fuller taught us a trick on using electric to heat at night. Since we like the bedroom cool at night, we turn on the HH electric at 65 in the living room and emerge in the morning from the cold cave in the bedroom into a warm living room.

Old, yes I will be at Quartzsite. We need to get a gaggle of interested owners together and tour various model coaches and brainstorm the issues.

[Twomed]

My Dynasty has the hose under the sofa deal for front/center heat. They used a bigger fan with a three position switch for that unit. West Marine has a 12 volt in line blower for flexible ducting you might adapt.

[Renipladlo]

Wayne - WOW!!!!, hope you make QZ as this is something I have not seen. I don't know how to overcome that install, but will give it some thought. Strange how no two coaches, even the same model are different, sort of like design on the go.

Basil - you may be correct, I used old brain cells to come up with that number, and did not check the manual. I have the shop manuals in the jeep, so will check once it warms up enough to go outside. Are you still home or are you here yet? Here would be in someplace near the rally sight, near would be within 100 miles I guess. Were in Ehrinberg, AZ moving to salome on the 5th.

[EngineerMike]

Here are some West Marine inline blower options.

The 36' SE Cozy units were pretty well thought out by the time they built my coach. The under-bed unit has a built in return, and most of the duct runs are short. The dash unit is center-mounted behind the console. Fit & finish were the only big drawbacks, along w/the grille area for the kitchen drawer & bath/bedrm closet register. I haven't bothered w/the register grill replacements yet as we've creatively avoided most seriously cold weather camping.

[DrDaveMA]

We have the maple interior making us VERY lucky, I got a maple vent at Lowes and cut an opening for it below the drawers in the bedroom, it looks like WRV installed it with the rest of the woodwork (maybe better)

[Renipladlo]

Dave - I like that Install. wonder if I can get down there if I take all the drawers out and surface mount my unit. I believe mine is even below that level in our coach, but based on that picture, it looks very similiar. Need to look closer. Thank you for the picture.

[Wayne R]

I think I might disconnect the ducts from under the closet drawer and just install a register similar to Dave’s except it would be heat instead of vent, Then I could find another spot to vent the area. That would double the heat output in the bedroom. The long flex hose runs to the shower and lav area are useless anyway.

I then may install another cozy unit in the bay ceiling or lav sink cabinet feeding the shower and lav area. I could use heating loop 3 and tie the bay thermostat to zone 2 in parallel. I don’t think running the bay heater anytime zone 2 is on would increase operating costs noticeably.

Is there any reason the zone 2 and 3 thermostats could not be wired in parallel. That way if it got below freezing temps while I was away zone 3 would come on and heat the bay and lav area.

[dgerstel]

Basil,

These systems are different, depending on coach year, length and model.

See here for my findings on HH, AH problems:

http://www.irv2.com/forums/f104/aqua...ues-17737.html

My findings since In reply to your list of areas.

LIVING ROOM:
Early coaches had wood boxes with air flow blowing out, but had long hoses to allow base cover to be removed. Later coaches had plastic part that blew air at the floor. This was my "temp" fix, that I am still using.



KITCHEN:
Different on front door coaches and mid door. On mine the drawers across from the fridge got very hot. Now with exchanger mods, ducts shortened and new outlet grill, the bottom drawer gets just barely warm.

BATHROOM:
On mine, hard to cure layout. Bad output under shower, and too long a run to the toilet room. Cabinet under sink got very hot, after exchanger mods, ducts shortened, toilet room heater vent modified and added air return (intake) grill, the cabinet does not heat up. I plan some future fixes.

BEDROOM:
My exchanger is in rear cabinet under drawers, the drawers got very hot and there was very little air flow, After after exchanger mods, ducts shortened, duct added, heater vents modified and added air return grill, the drawers do not heat up. I may move exchanger to under the bed.

DASH:
Have not addressed yet. Works OK.

Photos here of larger kitchen heater vent and new bathroom air return.

http://www.irv2.com/forums/f104/late...cts-38406.html

[Wayne R]

Dale, what is your opinion on just moving the heat exchanger and eliminating the hoses. I was also looking at some radiant baseboard heat exchangers offered on another website.