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Old 02-03-2011, 07:33 PM   #1
geo
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Thumbs up Warmed air circulation system on Alpine - Part 2

To all members and moderators - I apologize for the long post but this subject seems to have quite a bit of as of late. I wanted to be detailed enough that anyone could duplicate what I have done. I have had to load this post as two parts. However, I do want to add that Leon has the best suggestion: "Skirting".

Part 1 follows this post.

Ron


Plan 2: I purchased some vibration damping pads (Northern Tool or Amazon). I mounted the fan inside a shoe box (not a real project unless a shoe box is involved!) with short screws coming out the bottom of the box and attaching to the vibration pad. (See Foamed Fan.jpg) I linked that pad to another pad to another pad. I then took Door/Window Foam (minimal expansion foam – 3 cans) and foamed the fan as a whole totally inside the box. The foam extended above the top of the box so I could place the lid on it and have it foamed in place. Once the foam was set, I tested it and was quite pleased at the muffled sound.

The shoe box fan assembly was then attached to the deck by the vibration pads but the plastic duct shoved the assembly forward towards the furnace. I used a cable tie to pull the assembly back so the pads were vertical. (See Buffer Fan in Place.jpg) When the electrical was hooked up, I turned the switch on. I was extremely happy that the bilge fan was extremely quiet. In fact, the furnace fan is several times louder than the bilge fan!

To supplement this circulation solution, I used pink foam (R5) insulation to isolate the utility basement from the storage basement. (See Wall Insulation.jpg) I cut the foam to exactly fit between the supports – in fact it is a press fit. Earlier I had noticed that the vacuum connection for the storage basement was so low that it caused the feed pipe from the vacuum connection in the living area to become disconnected. I moved this connection to a higher location. I also cut and glued in place two layers of foam insulation on the roof area of the storage basement (between the aluminum rafters). I cut the foam to fit around the lights and channels to allow the electrical cables to pass.

In an additional post, I will show the two additional parts of this project. I have on order a 7” diameter low rpm 12 volt computer case fan that will move around 120cfm. I plan to mount this at the back of the lower step to force air from the living area into the upper utility basement area. The other part will be to mount foam insulation to the outside of the steel crossbeam. I believe I can use Liquid Nails to mount masonite “blocks” to the outside steel crossbeam. I can then cut the foam insulation to attach to the masonite blocks. The outside of the foam can be covered with melamine tub surround sheets cut to fit.
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__________________
2011 Alpine 3640RL (Beauty)
(Gone! Now replaced by Beauty3)
2016 Ford F-450 (The Beast)
Diesel 4x4, DRW, LB, CC
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Old 02-03-2011, 07:37 PM   #2
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Thumbs up Warmed air circulation system on Alpine - Part 1

To all members and moderators - I apologize for the long post but this subject seems to have quite a bit of as of late. I wanted to be detailed enough that anyone could duplicate what I have done. I have had to load this post as two parts. However, I do want to add that Leon has the best suggestion: "Skirting".

Ron




While diagnosing the fresh water fill problem of my Alpine 3640RL, I noticed that the furnace ducts were solely responsible for warming the tanks and utility basement area. The only air communication between the lower and upper utility basement was the area directly behind the WaterWorks area. I also noticed that the only “insulation” between the utility basement and storage basement was a wall of carpet-covered luan paneling.

I realized several problems: 1) Running the heat pump would not provide any “starting” heat to the tank space, 2) Running the fireplace heater or other heaters in the living space would provide no heat to the tank space, and 3) Unless the furnace fan was running, there was no warmed air supplied to the tank space. (See 3640RL.jpg)

My solution would be to force air from the upper utility basement area to the lower utility basement area.

I purchased a 4” diameter bilge fan, 2.5” and 4” clear duct used for woodworking dust vacuum systems with several Y’s and reducing adapters, and 3” aluminum flexible heating duct. The bilge fan is used in inboard/outboard boats to purge gas fumes from the bilge area. The model I purchased was advertised to be quiet and 325 cfm flow.

I knew from previous work on the fresh water fill system that there existed a tunnel in the lower utility basement that would accommodate a 3” duct. (See Tunnel.jpg) I used a ½” plastic electrical conduit to feed the 3” duct back into the tunnel by feeding the conduit through the storage basement door, behind the WaterWorks, and into the lower utility basement. From the left side, I fed the 3” aluminum duct into the lower utility basement and attached it to the conduit with a combination of duct tape and cable ties. (See Forward duct.jpg)

From above, I attached a short piece of lead-in 4” plastic duct to the fan. I then fed 4” plastic duct through a maze of water pipes behind the WaterWorks area and to the clear space where I planned to locate the fan. I attached the duct to the fan, and mounted the fan to the deck using neoprene washers. (See Bare Fan.jpg) Immediately below the Transfer Switch, I mounted a Y on the aluminum support to split the 4” plastic duct. (See Distribution Y.jpg) One side of the Y went from 4” clear duct to a reducer to fit in the 3” aluminum duct for the fresh water tank area. The other output side used a short piece of 4” plastic duct to bend back under the deck to the lower utility basement. There another Y with reducers branch into 2.5” plastic ducts. One of the 2.5” ducts I fed forward on the port side of the black water tank. I only had a short piece of 2.5” duct left, so I attached it and dropped into the area next to the forward gray water tank at the rear. (See Gray Waste.jpg)

I noticed that the furnace ducts to these tanks only focused the warmed air on the valve areas of these tanks. These valves were located next to the steel crossbeam that offered no insulation to the lower utility tank area. I have no clue as to where the furnace duct to the fresh water tank are terminates. I think this might only be answered with a trip to Keystone’s Alpine plant.

I purchased a waterproof switch which I mounted inside the WaterWorks area, fed the wires through a drilled hole, and sealed the hole with white silicon sealant. I tapped in to the 12 volt power line (parallel) to the WaterWorks light. I used a 10 amp inline fuse on the hot side between the switch and the tap into the light’s line. (See Back of WaterWorks.jpg)

All complete, it was ready to go! I turned the switch on and was rewarded with a loud scream of the bilge fan! I went around to the front door, entered, and stood next to the stairs. Holy Moley! I had to go outside to think, “That is way too loud!” I could feel the vibration of the fan while standing on the stairs and the in the bathroom!
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__________________
2011 Alpine 3640RL (Beauty)
(Gone! Now replaced by Beauty3)
2016 Ford F-450 (The Beast)
Diesel 4x4, DRW, LB, CC
Comfort Ride Hitch
geo is offline   Reply With Quote
Old 03-10-2011, 08:52 AM   #3
geo
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Circulating fan between living area and basement.

It is the furnace that warms the tank and basement area. Running the heating fireplace and/or heaters in the living area of the Alpine puts little heat the upper basement area. The back of the steps are grooved to allow air flow between the upper basement and the living area. The back of the stairs is held by four square drive screws and press fit.

I got a 200mm (7.8”) computer case fan (from Amazon) that was low rpm, low noise, 12 volt, and moved 105cfm. The fan has a two-pole microplug connector which was wired in parallel to the bilge fan. I removed the upper grooved stair back and retrieved the two pole microplug and connected it to the fan. I positioned nylon spacers between the mounting holes so the mounting “ears” would not snap off if stressed. This was done for two of the upper mounting ears. Using 10 x 1 ˝” square drive screws, the fan was mounted at one side of the lower stair cavity such that it draws air from the living space. The fan was positioned such that the side of the fan was inline with the edge of the step. A 1” spacer was placed next to the fan and screwed into the basement floor to keep the fan firmly against the stair frame. The remaining open area around the fan was covered with 4” wide x 9” long x1/8” thick hardwood plywood strips left over from rebuilding the bathroom doorframe for a folding door.

When freezing temperatures are supposed to occur, the circulating fans can be switched on from the waterproof switch in the WaterWorks area. As the two posts above illustrate (sorry for posting Part 2 before Part 1), the bilge fan moves 370 cfm of air from the upper utility basement area to the lower tank basement. The case fan not only draws air from the living space, but it also circulates air around the flexible aluminum ductwork from the furnace. Thus, if the furnace is running, it allows the air to be warmed further to circulate around the tanks. Another plus of the computer case fan is that it has four blue LEDs which send a warming glow from beneath the stairs with operating.

By no means do I believe that this will keep the tank area from freezing under extreme conditions. Wolfwalker is correct that skirting will give some of the best protection against the tank area freezing. But I think that the warm air circulation will help keep the Alpine tanks and pipes from freezing as the temperature approaches 20 F (-6.7 C). Anything colder than that needs additional protection, such as skirting.
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__________________
2011 Alpine 3640RL (Beauty)
(Gone! Now replaced by Beauty3)
2016 Ford F-450 (The Beast)
Diesel 4x4, DRW, LB, CC
Comfort Ride Hitch
geo is offline   Reply With Quote
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