1st Build, a 5'x8' Foamie Teardrop on a 4'x8' HF Trailer

[lthomas987]

With the trailer levelish how high is the top of your 1x4 frame from the ground? I'm curious. I have the same trailer but it is stored away from my house at the moment and I haven't seen it in months. Once the spring thaw comes though I am going to start building a 5x8 foamy on it. So you shouldn't be surprised that I am watching your build very carefully.

Laura

[jseyfert3]

With the trailer levelish how high is the top of your 1x4 frame from the ground? I'm curious. I have the same trailer but it is stored away from my house at the moment and I haven't seen it in months. Once the spring thaw comes though I am going to start building a 5x8 foamy on it. So you shouldn't be surprised that I am watching your build very carefully.

Laura

23.5" - 23.75". So just a hair over 2' once the OSB is on. With the peak of my trailer at a planned 4' off the floor and 2" for the roof foam, that will put the Teardrop at a max outside height of just about 6'2".

Watch and ask away!

Tomorrow I'm hoping to plan the mount for the AC and battery and maybe get them build or at least started.

[jseyfert3]

Here is my AC unit, a 5000 BTU GE Model# AEW05LQ from Walmart. It was $139 with tax. I would have gotten a smaller unit but 5000 BTUs seems like the smallest size they make ACs in unless it's a specialty AC unit. It has digital controls and a remote, the controls will be relocated to the inside of the TD.


GE Model# AEW05LQ 5000 BTU AC by jseyfert3, on Flickr

This is the planned location, with the top of it almost flush with the bottom of the floor. At this height, the bottom is approximately at the height of the top of the axle, so I'll have plenty of ground clearance.


AC in Planned Spot by jseyfert3, on Flickr

Since the AC is not made to blow air through long vents, I picked up a Rule 240 marine bilge blower from Amazon. This will be used as a booster blower and will be wired up to run when the AC blower motor is running. I also picked up a generic 12 V AC adapter to power it. I tested it by touching the wires and it certainly blows a lot of air. A bit noisy, but it will be mounted under the trailer with foam between it and the floor so it probably won't be audible over the AC itself.


Rule 240 Marine Blower by jseyfert3, on Flickr

I will be thinking more on how to mount the AC and battery tomorrow. Right now I'm thinking a support cage made out of 1x2s with foam and canvas walls.

[KCStudly]

Cool! (Pun intended.)

Why convert AC to DC if you are already going to have a battery on board? The only reason I can think is because you will only be running the A/C with shore power and you don't want the booster blower to draw your battery down; but if you are running shore power won't your battery be on a charger? Is there a 120v blower that could have done the job?

[jseyfert3]

Cool! (Pun intended.)

Why convert AC to DC if you are already going to have a battery on board? The only reason I can think is because you will only be running the A/C with shore power and you don't want the booster blower to draw your battery down; but if you are running shore power won't your battery be on a charger? Is there a 120v blower that could have done the job?

Not necessarily, I didn't intend to install a battery charger, at least initially. Down the road I probably will, but I figured the majority of my charging could come just through using my car to charge while I tow. Easy and simple to connect the TD battery to the car when driving and have it unconnect when you shut the car off.

Anyhow, it's not a big deal, as this blower will only be running when the AC is, which means I'd have shore power or a generator (not likely on the gen). For 12 VDC no shore power applications, I have a Fan-Tastic fan for ventilation.

I got the 12 VDC blower because that's what popped up when searching blowers on Amazon. Going back after your comment, I see there are 120 VAC blowers, however, these have thin metal bodies like furnace ductwork. As a marine blower, this has a solid plastic body and a rubber cap over the end of the motor to make it waterproof. Since I'm hanging it from my TD floor, this is an advantange, if water somehow leaked into the vent lines, the blower should not be bothered by it.

[KCStudly]

Understood.

How will you protect the A/C unit from moisture damage from driven mist/rain? This is why I like what OakInteriors is doing with the under slung rail that will allow him to slide his unit out from under the TD easily for dry storage while going down the road.

[jseyfert3]

Understood.

How will you protect the A/C unit from moisture damage from driven mist/rain? This is why I like what OakInteriors is doing with the under slung rail that will allow him to slide his unit out from under the TD easily for dry storage while going down the road.

I'm planning to make a box around it. I was thinking foam walls with canvas, just like the TD. On the front since that would be battered with high speed rocks use a layer of thin ply or plastic (probably plastic) to protect the foam. The rear side would be hinged to open up at the campground for condenser coil ventilation.

See any issues with this?

[jseyfert3]

Understood.

How will you protect the A/C unit from moisture damage from driven mist/rain? This is why I like what OakInteriors is doing with the under slung rail that will allow him to slide his unit out from under the TD easily for dry storage while going down the road.

I'm planning to make a box around it. I was thinking foam walls with canvas, just like the TD. On the front since that would be battered with high speed rocks use a layer of thin ply or plastic (probably plastic) to protect the foam. The rear side would be hinged to open up at the campground for condenser coil ventilation.

See any issues with this?

[jseyfert3]

I'm spending way too much time playing Minecraft. Played all morning and into the late afternoon. After I dragged myself away, I finished up the floor framing. The 1x4 over the axle can't go the the 1x4s on the edges, so this is what was suggested to do for that. Basically an H-shape piece between the two other crossbeams. To start, I cut out the 1x4s pointing forward, and screwed them in place. I then cut the 1x4 that points sideways, and screwed it into place. I then unscrewed the whole H-shaped piece and removed it.


H-Shape Piece Before Gluing by jseyfert3, on Flickr

I unscrewed it, then glued it together as I glued the previous 1x4s, doing one side at a time.


H-Shape Piece After Gluing by jseyfert3, on Flickr

I then thought: "This was not the best order to glue everything back together", as I now had to glue and screw all four joints of the H-piece. Despite my initial concerns, it went in okay and I didn't drip too much glue on the ground. Installing this finished up the floor framing.


1x4 Framing Complete (1) by jseyfert3, on Flickr


1x4 Framing Complete (2) by jseyfert3, on Flickr

A better view of the AC unit, located approximately where it will be mounted. The supports for the AC will attach to the top and bottom 1x4s, and I can attach to the left one if needed and run a 1x2 on the right side of the AC between the 1x4s. Still thinking of it, but soon I'll just be going out there and whipping up something that "looks right". I want to get the mount gluing tonight so I can start coating the frame with the mix tomorrow.

As planned, I believe the AC mounting box will extend 14 3/4" below the bottom of the floor. This is about 1/2" below the bottom of the axle where the axle currently rests, and the front of the box would be about 16" forward of the axle. This means 16" forward of the axle I'd have about 9 1/4" ground clearance. Since my car has only around 7" of ground clearance I think I'll be fine with this. Even if the hitch is resting on the ground there would still be 6" of ground clearance at the front of the box.


Rough AC Location by jseyfert3, on Flickr

I'll be also installing a battery box on the right side of the camper. It'll be sized to hold a group 27 deep cycle battery. A Trojan 27TMX deep cycle battery has 105 Ah at a 20 hour discharge rate (5 A). At most I'd be using around 4 A for lighting and the vent fan on high, so this capacity should be valid for me. At medium, the vent fan pulls 2.3 A, so for low lighting usage, fan on medium, I would get 36 hours of runtime to 80% discharge and 23 hours to a battery friendly 50% discharge level. Simply put, 4 nights for max battery usage, 3 nights for long battery life. This could easily be extended by the future addition of a solar panel and solar charger (future plans, if needed, which is doubtful at this time). Of course, the battery will not even be used on nights I'm using the AC, since the AC requires camping at a campground with electricity. The battery just adds flexibility to allow camping in areas that do not have electricity when the AC is not required to get a good nights sleep.

The boxes will be constructed of 1x2s with a piece of the 1/2" OSB resting on the bottom for the AC/battery to sit on. I will use foam walls, either 1/2" or 1" thick, and cover them in canvas, similar to how the TD is constructed, but they won't provide much if any structural support in this case. The condenser coils on the AC will probably face forward, and there will be a hinged panel on that side that opens up to let cool air in when the AC is running. I was thinking of facing this panel backwards, but the picture made me realize that airflow to the condenser coils will be limited in that regard due to the tire, as well as the fact that it would make access to open the panel more difficult then it needs to be. If forward, this panel will be made of 1/2" OSB as well, for rock resistance. The front of the battery box will be hard plastic or thin OSB/ply for the same reason. They will take a beating front flying rocks that my car tires kick up.

I'm curious about the wooden side frame rails. They appear to run long at the front. Will those get trimmed off later or does something else go there?

Here's a better view of them. They run as long as the trailer does. I'm using the gap between the front 1x4 and the trailer crossbeam to run AC and outside air vents. The side rails continue to go to the front so the bottom edge is the same height the whole length of the side.


Side 1x4s at Front of Trailer by jseyfert3, on Flickr

[KCStudly]

Several people have had problems when they boxed in the sides of their A/C's. Make sure you have figured out which air goes where for condenser cooling/exhaust, and makeup air/recirculation. Just having one hatch to the rear sounds like it may be too restrictive (based on what I have read of other peoples installs). IIRC, I have seen some people have to add dividers to
the side grilles to keep the air patterns from mixing.

On the other hand, you seem to be smart enough to figure it out, once you have studied what other people have done to correct the issues that they have had.

I seem to recall Big Mike having to hack up (redesign) one of his installs due to this issues. There have been others, too.

[jseyfert3]

Several people have had problems when they boxed in the sides of their A/C's. Make sure you have figured out which air goes where for condenser cooling/exhaust, and makeup air/recirculation. Just having one hatch to the rear sounds like it may be too restrictive (based on what I have read of other peoples installs). IIRC, I have seen some people have to add dividers to
the side grilles to keep the air patterns from mixing.

On the other hand, you seem to be smart enough to figure it out, once you have studied what other people have done to correct the issues that they have had.

I seem to recall Big Mike having to hack up (redesign) one of his installs due to this issues. There have been others, too.

I had noticed that the condenser fan pulls air in through both sides and the top and blows it out through the coils, and planned on leaving at least 3 inches or so on each side, and perhaps a side that opens up as well. I will however do a search on AC problems, thanks for the heads up.

[jseyfert3]

This the big Mike cut-up you were talking about? viewtopic.php?f=2&t=56931

[KCStudly]

This the big Mike cut-up you were talking about? viewtopic.php?f=2&t=56931

Yup.

[KCStudly]

The problems that most people have seem to be recirculation of the hot air from the condenser. If the air being drawn in to the sides and top has to come past the exhaust, it can drag that hot air back in. The other problem people seem to have is icing up, which, IIRC, comes from failing to recirculate the conditioned air.

Again, this is just from my memory and may not be 100/ct correct. I don't have any plans to run an A/C, at least for now, so I haven't studied these issues in earnest, but I have read enough to know that it is seldom as easy to "hack" an install as it seems that it should be (hack = anything other than straight thru wall install where air is redirected from factory design). Learning from those that have gone before is worth the time, and can be every bit as stimulating as video games.

You're doing a good job so far. Keep at it.

[jseyfert3]

The problems that most people have seem to be recirculation of the hot air from the condenser. If the air being drawn in to the sides and top has to come past the exhaust, it can drag that hot air back in. The other problem people seem to have is icing up, which, IIRC, comes from failing to recirculate the conditioned air.

Again, this is just from my memory and may not be 100/ct correct. I don't have any plans to run an A/C, at least for now, so I haven't studied these issues in earnest, but I have read enough to know that it is seldom as easy to "hack" an install as it seems that it should be (hack = anything other than straight thru wall install where air is redirected from factory design). Learning from those that have gone before is worth the time, and can be every bit as stimulating as video games.

You're doing a good job so far. Keep at it.

Icing I should not have a problem with. I'll be venting in cold air near the galley side and venting hot air back to the AC from vents near the ceiling on the front side.

Hacking may not always be easy, but it sure can be fun! I enjoy it. My AC will certainly be hacked, since I'll have the vents running to the AC, and removing the control unit to mount inside the TD. Fun stuff.