Newbie Looking Leaning Towards a Foamie (My Question Thread)

[jseyfert3]

Okay. Bear in mind this is an initial sketch, just to get my general idea down. I was not intending it to specify exact sizes and materials that would be used, just a general idea I have in my head.


Battery Mount Sketch (1) by jseyfert3, on Flickr


Battery Mount Sketch (2) by jseyfert3, on Flickr

I was originally thinking the "main" support would be a wood beam of some sort, which is why it's square. This I figured would take most of the load of supporting the battery. But since the battery is forward of the bottom of the support, it wants to "fall forward" in simple terms, and the only way I could see to help support that was running some angle iron or similar (C channel or square tube would probably be better) to the edges, where a thin strip of steel or aluminum would run forward in a channel in the foam and anchor into of of the wood sub-frame supports.

I was not intending it, but I thought after I got done (3D sketches are very useful, I'm finding!), that the OSB "headboard" could also be used as a vertical support on one side of the battery to carry some of the load, especially if reinforced with some strips of 1x2 framing or similar to help stiffen it.

This would require a small vent of some sort on the front of the trailer, to allow hydrogen gas that could be generated to leave, as a vent on the bottom would not allow that since hydrogen rises. Then a small vent at the bottom of the trailer to let air in.

Certainly, my sketch seems to help me see it's doable, even if what I have is not the best way to mount it, and I'm certain it's not. Thoughts?

 

[GPW]

May not be the best place to mount it ... especially up so high ...

 

[KCStudly]

How about under the floor near the axle? Just ahead or just behind it. Check out how Danny does his in traditional builds. I think Zach's X2 had an under slung battery, as well.

 

[GPW]

Anybody ever salvage an Auto battery box (boneyard), and just bolt/weld it to the trailer.. ?

 

[Mary C]

Js and KC and you other guys if I didn't know any better I would think you are building a spaceship going to the moon, Keep it simple. I own an oil well that gets a profit and it is .00000000024 and that equals to 16 cents a year. Now that is really a lot and that is at full production and if it is not, they want 6 dollars a year. So you figure it out. It is not worth the paperwork for me but it is fun. So if discussing the .000074 and the perfection of all the ratios just make sure it is worth your time and effort to change it for the better. so......I will be just KISS for me I am not worried about those .00000000things there are bigger fish to fry, speaking of fish I need to go fishing........ winter is making me crazy!!!!!

No, put the battery LOW. I cant tell you exactly why, but I saw a batterys damage on a person once (acid) and I would put it low, protected and away from persons.

Mary C.


edited twice to get the spelling just right

 

[KCStudly]

It's just a little "knowing" and a little math, Mary. Just one of the things that I like to do for fun, and because it exercises my brain. The fact that we were talking decimal points is the exact answer to JS's question; 'nope, it does not matter so don't worry about it, and... here is the scientific proof'.

It's too cold to build here, so I guess I got a little bored.

 

[jseyfert3]

Indeed Mary, I agree with what KCStudly said, I understand what he posted and enjoy doing stuff like that, or I would not currently have my Associate in Engineering Science Degree and be continuing towards my B.S. in Mechanical Engineering this fall. In fact, I want to (just for fun) calculate the stresses in the wood caused by the said 0.0000017 in/in / ­°F. Especially cause it's bugging me that I didn't remember why the units where in/in (don't tell me KCStudly!).

So yes, I was worried about thermal expansion, but the 0.000017 was just to show that it was nothing to worry about.

Don't worry, I AM pushing ahead with the build, and I'm trying to KISS, but my brain keeps getting in the way.

No, put the battery LOW. I cant tell you exactly why, but I saw a batterys damage on a person once (acid) and I would put it low, protected and away from persons.

Hmm, I didn't think about that. Very good point, thank you Mary!

How about under the floor near the axle? Just ahead or just behind it. Check out how Danny does his in traditional builds. I think Zach's X2 had an under slung battery, as well.

I'll see if I can find that. It didn't occur to me to put it there, as I would have thought a 12" battery could have some ground clearance issues. But on second thought, with the raised floor, it would still have more clearance then my car itself does, as the HF trailer sit somewhat high in the stock configuration.

So, tonight, start drilling holes and mounting hurricane ties! Then, slide the battery in my model up under the trailer, in front of the axle, so I can "see" the ground clearance. And convert the forward area into small cabinets for storage.

Right now, I'm thinking mount the AC up above the bed (why am I putting all these heavy things high? ), above the axle, so if it's not hot I can take it out. Vent the heat out with computer fans and tubes to below the trailer, or add a small hatch in the galley hatch that pops open when the AC is on.

 

[KCStudly]

On a street going camper (as opposed to an off road rig) ground clearance is like a triangle; greatest near the axle tapering toward the tongue and rear "bumper" (assuming that nothing pokes up higher than the axle). Near the axle is not affected by dips and transitions.

Here is a link to a thread on under slung battery mounts.

 

[jseyfert3]

On a street going camper (as opposed to an off road rig) ground clearance is like a triangle; greatest near the axle tapering toward the tongue and rear "bumper" (assuming that nothing pokes up higher than the axle). Near the axle is not affected by dips and transitions.

Here is a link to a thread on under slung battery mounts.

Cool! I will plan on that. Also, about the AC, I asked my coworker where I should put it (for ideas), and he said underneath. If it will work for a 12" tall battery that weights 50-60 lbs, it'll work for a 12" tall "window shaker" that weighs only 43 lbs, right?

Cool! Planning will commence on these lines!

 

[KCStudly]

A/C location is always a compromise. I don't plan on having one, but have read all I can so can pass on what I have read.

Up front can create an issue with weather tightness since driving forces rainwater in thru any chink in the "weather proofing armor". Also, some people don't like the cool air drifting down on their heads.

Galley mounted units need careful attention to sealing the area underneath, "the pan", and a means to control drainage. They take up room in the galley and several have had venting/crosstalk/heat soak issues due to improper venting and duct routing.

Some have made adapters that allow them to remove a side door and install the A/C in place of, but they usually give up the use of the door (no bueno).

GPW's Foamstream has a side hatch that will allow him to pop the unit in when needed, but then his is a larger camper and has room for that.

Divorce d units where the unit sits on the ground next to the camper or on the tongue may have portable or permanent hoses to duct the air to and from, but you will need to hack the thermostat and controls for remote operation, and build the necessary shrouds.

In any case, they have to be mounted high enough that the bedding does not interfere with the ducting.

Oakinteriors is currently working on a rather ingenious install where he made built in ducts between his bulkhead and rear cabinets, and is mounting the unit hanging on a sliding rail under the floor. Travels onboard, but slides into position underneath during camp setup. Don't need it, leave it at home.

Many people don't bother, depending on the climate where they camp.

Look at Aggie79/Tom's Silver Beatle. He uses a Pet Cool unit mounted in the tongue box. Planovet's Little Swiss has his mounted behind the bulkhead. Other build's from Texas seem to have the bugs worked out since A/C is a "must have" for that region.

 

[Mary C]

KC, I have to harass you and Js a little, like I said i am using the KISS method and ya'll do not bother me a bit I just thought I would harass you two a little. Now I have not thought about where I am going to put the A/C this week, so I will not pay attention to that decision. Js you just plan away but don't get too attached to any one idea I can tell already that you are still planning. I am working on the wood for my Wiley windows. Js, you are doing great even if only planning!!!!! Take one thing at a time, and keep it fun!!!!

Mary C.

I got my HF sale paper, gotta go study it!!!!!

 

[jseyfert3]

KC, I have to harass you and Js a little, like I said i am using the KISS method and ya'll do not bother me a bit I just thought I would harass you two a little. Now I have not thought about where I am going to put the A/C this week, so I will not pay attention to that decision. Js you just plan away but don't get too attached to any one idea I can tell already that you are still planning. I am working on the wood for my Wiley windows. Js, you are doing great even if only planning!!!!! Take one thing at a time, and keep it fun!!!!

Mary C.

I got my HF sale paper, gotta go study it!!!!!

I know, plans can change quick. I'm just afraid if I think of only one step at a time, I may have to undo that step because I didn't think about running wiring or something.

Also, I'm not only planning, I am building (slowly) too. You posted on the thread I talked about ruining a bearing and seal, cause I was trying to pack the bearings. Because my HF trailer is assembled, besides bolting on the coupler, fenders, and tires. It's not upside down anymore either, it's upside right and I'm planning on attaching the floor mounting brackets tonight, and getting 1x4's soon to start assembling my sub-floor.

Trailer - 90% Assembled by jseyfert3, on Flickr

 

[jseyfert3]

I needed to mount my vise, but discovered the mounting bolts where too short for the bench at my house. The only other bolts I had were too long, until my eye fell on some 2x4 scraps laying around. Long bolt problem solved, no new bolts needed.

Vise Mount by jseyfert3, on Flickr

After I got that mounted, I made a corner bracket to mount the end cross beam 1x4s, using the vise and a hammer.

Patent Pending Corner Bracket by jseyfert3, on Flickr

That, and a little clearing of the garage is all I feel like doing tonight though, it's popcorn and Star Trek time, then bedtime.

 

[KCStudly]

Nice job on the corner bracket.

That should work just fine.

 

[jseyfert3]

A/C location is always a compromise. I don't plan on having one, but have read all I can so can pass on what I have read.

Up front can create an issue with weather tightness since driving forces rainwater in thru any chink in the "weather proofing armor". Also, some people don't like the cool air drifting down on their heads.

Galley mounted units need careful attention to sealing the area underneath, "the pan", and a means to control drainage. They take up room in the galley and several have had venting/crosstalk/heat soak issues due to improper venting and duct routing.

Some have made adapters that allow them to remove a side door and install the A/C in place of, but they usually give up the use of the door (no bueno).

GPW's Foamstream has a side hatch that will allow him to pop the unit in when needed, but then his is a larger camper and has room for that.

Divorce d units where the unit sits on the ground next to the camper or on the tongue may have portable or permanent hoses to duct the air to and from, but you will need to hack the thermostat and controls for remote operation, and build the necessary shrouds.

In any case, they have to be mounted high enough that the bedding does not interfere with the ducting.

Oakinteriors is currently working on a rather ingenious install where he made built in ducts between his bulkhead and rear cabinets, and is mounting the unit hanging on a sliding rail under the floor. Travels onboard, but slides into position underneath during camp setup. Don't need it, leave it at home.

Many people don't bother, depending on the climate where they camp.

Look at Aggie79/Tom's Silver Beatle. He uses a Pet Cool unit mounted in the tongue box. Planovet's Little Swiss has his mounted behind the bulkhead. Other build's from Texas seem to have the bugs worked out since A/C is a "must have" for that region.

Hmm.

I'm still thinking that mounting it under slung, but with no fancy slide-in/slide-out mechanism may satisfy getting it out of the way since they take up a lot of space in a 5' x 8' TD, but still be a fairly simple (not quite KISS) install. Hardest part is protecting from road debris and ducting, but remote switches and controls are no problem at all. In fact I was planning on modifying the controls with a small microcontroller to tweak operation to my liking and hold a better temp, if possible in such a small, insulated area.

That also means a portable unit connected with hoses is no issue for me, as I do not fear the controls (in fact would be a fun mini-project ), but an portable unit needs to be stored somewhere while moving, lifted in and out at least four times per trip, connected and unconnected, etc. I think I'd rather take the weight penalty for always dragging it around if it's both out of the way and no need to mess with it.

What I'm thinking is if I mount it under the floor like the battery, I'd run ducting below the floor, and up into the TD at the foot (by the galley) of the bed, raised so our feet don't freeze. The A/C would pull fresh air in from underneath the TD and cool it, push it into the back of the TD sleeping area, to the front of the bed, where it would enter vents in the "headboard" of the bed, through more ducting to vents in the bottom front of the trailer.

This particular setup also means with rain and no AC required, windows could stay shut but a roof vent pulling air out (with a rain hood), would pull fresh air in the vents at the front in the headboard, right past our faces while we sleep.

Pros of this particular setup: Fairly easy to do, no fancy moving mechanisms required. AC does not need to be loaded/setup every time. Vents near front and the vents for the AC in the rear double as fresh air intakes with a roof vent exhausting air, if AC is not running, which allows fresh air with windows shut for rain/noise, and requires no visible vents on the outside of the TD besides the roof vent, a big plus. Takes up no space inside the TD except for the rear vents (front vents take up no practical space).

Cons: There is custom ductwork of some sort required (one time deal), remote controls (not even really a con for myself with my Arduino microcontroller/minor electronics experience), not easy to access AC unit for cleaning, requires a waterproof/dustproof enclosure to protect from road spray/debris, probably including a panel that can shut while traveling and open to allow condensor coil heat exchange (I wonder how difficult an automatic electronic panel would be, open when AC is in use, close when AC is shut off...). A manually opened panel should not be terribly difficult however.

Ever heard of an AC install like how I'm envisioning it? Need a 3D sketch?

Anyhow, I really have to get off here and GO WORK ON MY TRAILER! Enough planning, planning doesn't actually build. Got enough computer stuff done today, I have Windows installed as a virtual machine on Ubuntu now, I was tired of rebooting my computer into Windows just to work on my Sketchup model then boot back into Ubuntu for everything else. I'm installing Windows updates as I type on my laptop's monitor while Firefox is open on my 21" desktop monitor connected to my laptop (I no longer use a desktop) which is running Ubuntu.

Screenshot from 2014-02-08 23:37:51 by jseyfert3, on Flickr

<Edited because I put evaporator coil and I meant condensor coil.>

 

[KCStudly]

Before you make any final decisions on the A/C, I highly recommend that you study up on other peoples successes and failures. There are a lot of threads on A/C. (Use the Google search feature in the header.)

Some of the issues that people before you have had with a total loss system (non-recirculating) is that they do not get the dehumidification benefit, which is a big contributor to comfort level in hot muggy weather. Also, icing of the evaporator and short cycling are common problems with this setup (IIRC).

On the flip side, not having good separation between the condenser and evaporator air flows, and choking off the flow with add on ducting are regular pitfalls that people run into. Study up.

Don't assume that you can pull outside air thru an A/C when it is not running. For some reason that doesn't sound right to me (tho I am certainly far from an expert on this subject). I suppose if the vent feature is a manually selectable mechanical device, then yes; but that is another operator that would need to be "remotified".

 

[jseyfert3]

Before you make any final decisions on the A/C, I highly recommend that you study up on other peoples successes and failures. There are a lot of threads on A/C. (Use the Google search feature in the header.)

Some of the issues that people before you have had with a total loss system (non-recirculating) is that they do not get the dehumidification benefit, which is a big contributor to comfort level in hot muggy weather. Also, icing of the evaporator and short cycling are common problems with this setup (IIRC).

On the flip side, not having good separation between the condenser and evaporator air flows, and choking off the flow with add on ducting are regular pitfalls that people run into. Study up.

Don't assume that you can pull outside air thru an A/C when it is not running. For some reason that doesn't sound right to me (tho I am certainly far from an expert on this subject). I suppose if the vent feature is a manually selectable mechanical device, then yes; but that is another operator that would need to be "remotified".

Hmm, there would be at least some dehumidification. I know that's important though, so I will definitely look into that. Seems I read about someone doing a total loss system to allow better dehumidification, his thinking IIRC was that in such a small, well insulated area, it cools down so fast and stays cold so long it doesn't run long enough to remove the humidity. Not only is there initial humidity, but humidity build up from the occupants as well. I can see how fresh air could contribute to icing, due to high humidity of the outside air, however, I fail to see why it would cause short cycling, unless the short cycling was due to the evaporator coil icing. On the flip side, if you do not recall correctly, fresh air is also warmer, so I can see it helping to prevent icing.

Either way, I do need fresh air throughout the night. Hmm...(Mary, that "Hmm" means what follows is definitely not the KISS method. ). I wonder if I could set up a recirculating A/C with a DIY heat exchanger of some sort to allow waste condenser coil heat to warm some part of the air using a diverter. This would allow the AC to go into dehumidification mode where it dehumidifies without heating or cooling. Then either allow a small amount of fresh air in while running or use vents for fresh breathing air.

Dehumidification actually does have a KISS method though. Use a 1500 W tiny space heater, which is 5100 BTU, which balances the 5000 BTU A/C. This would require 20 A wiring and a 20 A outlet (most State Parks around here have 20 A 120 VAC outlets, IIRC), or two 15 A outlets and two 15 A circuits. Also stays with the KISS methodology as I wanted a heater. Pretty simple to control, have a humidity sensor with microcontroller and when humidity is too high it kicks on both the heater and A/C till the humidity drops, and if it starts getting too hot or cold cause one or the other is "winning", simply shuts that one off till the other "catches up". Not efficient in the least but fairly KISS, IMO for my capabilities.

If there was a way to dehumidify and control temp automatically like that, not much harder to add in a small diverter that uses the A/C fans to bring in fresh air every so often for breathing. Not all the time to prevent icing and keep the humidity down, but enough to take out the CO2 and bring in O2.

I understand that it may not sound very KISS, but controlling the humidity automatically seems like the best way to me to help prevent a few problems and make up for the fact the A/C is grossly oversized for such a small, well insulated space. However, before I build, I will most definitely research what already works for people here, as you said. I know that icing, or being cold but muggy would be no fun.

I thought up this dehumidification method of heater balancing A/C while sitting here typing.

Anyhow, I did get into the garage before coming back here to reply, check it out. Your idea, beginning implementation.

First Hurricane Tie Mounted by jseyfert3, on Flickr

 

[KCStudly]

The brackets look like they are going to work great for you.

I can't take credit for the idea, tho, I'm sure someone here had the idea first and I just was able to pull it up from the gray area in my head.

 

[Mary C]

I am seriously thinking about just building or finding some type of stand to set the A/C next to the open door of the TD and building some type of cover (a piece of Foam) to set above it to close off the outside air, similar to Eagles A/C set up. I don't plan to use it often but in the south we get high humidity and need the cooling. so for now, I will keep thinking about that to a minimum I still have other things to think about. Gotta go sand some wood..................

Mary C.

 

[ParTaxer]

If you can do without one of the doors when needing A/C, I did just what Mary C is talking about. I cut a piece of mdf to fit the door after the window unit was placed on the low end of the door. Both the A/C unit and the panel are secured from the inside. I only take it along when heat will be intolerable.

Mike W