More design ideas/questions

[Bogo]

My favorite 12VDC AirCon solution was always Glacier Bay's DCBreeze. At the time I was doing the vehicle research (2006), they did not have their vehicle (non-marine) unit in production yet.

All the truck systems with any reasonable capacity that I was able to find all used inverters and 120VAC compressors.

I can believe it.

http://www.climacab.com/index.html
8000 BTU. 12VDC input, high voltage BLDC motor. No Amps given. Uses 4 100 Amp hour AGM batteries and their battery pack is the right size for them to be group 31 size. Use is 8-10 hours on that battery pack and they warranty it for 2 years. The best deep cycle AGM batteries I know of are only specified for 350 cycles to 80% DOD so they can't be discharging it to 80% DOD to get two years of daily use. I figure the would have to plan for at minimum 500 cycles for two years use in a fleet truck cab. Some trucks may get 600 plus nights but it is very unlikely.

 

[Bogo]

The links for what I found are here: http://www.hackneys.com/mitsu/index-resources.htm

Scroll down for the Air Conditioning section.

There are 22 links for AirCon suppliers.

Lots of good links. Thanks.:safari-rig:

 

[Bogo]

Discharging deep cycle batteries, such as AGMs, lower than 50% on a consistent basis will dramatically shorten the service life of the battery.

I should have said absolute maximum instead. I'm familiar with >50% DOD being harder on AGM lead acid batteries. On the other hand many people on this list are only going for a month or two trips and have limited weight capacity. As such pushing the limits isn't a real killer. Most will have age or self discharge related battery problems before the life cycle is killed by discharging it down to 80% DOD every so often. A well tuned battery charger hooked up while the cruiser/RV/whatever is parked will do more for battery life expectancy than limiting to 50% or less DOD.

 

[Bogo]

While writing up these posts I remembered Saft STM series flooded NiCd batteries for EV use. A good AGM battery has close to the same energy density, and the Saft will cost more, however the Saft can safely be discharged to 80% DOD at 2C current rate for 3000 cycles before dropping below 80% of original capacity. They require you to add distilled deionized water every so often to keep the electrolyte level up above the plates and that you cool them to keep them from overheating. Cooling can be via water or air, but at 1/4C or lower discharge and charge rates cooling should not be needed. Charging is by a bulk charge at 1/2C till what was removed is returned or a set point voltage is reached. If you are wondering, SAFT has been making them for over 30 years and their life expectancy is legendary in the EV world. I remember their brochures back in the early '80s and then they only touted 1,500 cycles to 80% DOD. Real world experience has proven them capable of well over 3000 deep discharge cycles with many of the original ones still on the road today. People are now joking that they out live the vehicles they are installed in.

 

[whatcharterboat]

Unfortunately, with electrons, there is no free lunch.

Dou>>>>g I'm with you. At work we go through this debate every time someone want's a full blown expedition rig. IMO If you want Air con, run the genset. Carrying enough batteries just isn't viable. Especially if you are camped up for a few days.We had a hard a really hard look at it for the camper that had the DC "Powermaker" . If you remember the thread. In the end we couldn't warrant the weight.

Our camper aircon is 120VAC, so we need to run our 120VAC genset to power it.

Mick>>> I took this for you on the weekend. Saw it in the servo on the way back from Victoria. It's obviously one of the Waeco's I mentioned on the roof of a Hi-Ace. Suppose you've seen them anyway. They've been out for a while.

Bogo>>> You seem to pretty knowledgeable about all things that are cold. Do you (or anyone else) know anything about evaporative coolers or more importantly the components to make your own. I took a pic today of a piece of foam that apparently came from the US. It's about 2" thick by 10"x 10"> that's a can of Coke in the background.

It forms the basis for an evaporative cooler along with a computer fan and a shroud / tank to hold a litre ( I think) of water. Do you know of a supplier in the US who might sell this foam??? It has a screen embedded onto the outside.

Thanks John

 

[granitex1]

That looks exactly like the core in the humidifier, on my furnace. what are the dimentions of the one that you need?

 

[Bogo]

Bogo>>> You seem to pretty knowledgeable about all things that are cold. Do you (or anyone else) know anything about evaporative coolers or more importantly the components to make your own. I took a pic today of a piece of foam that apparently came from the US. It's about 2" thick by 10"x 10"> that's a can of Coke in the background.

It forms the basis for an evaporative cooler along with a computer fan and a shroud / tank to hold a litre ( I think) of water. Do you know of a supplier in the US who might sell this foam??? It has a screen embedded onto the outside.

Thanks John

I don't know anything about evaporative coolers except that they require a hot dry climate and lots of water to work. They also make the air muggy. They are also called swamp coolers. They are also prone to harbor mold. That's about it. From what I know I don't want one. I've often thought they should be outlawed as where they work best there is little water and it is best used for other uses.

 

[Bogo]

If that doesn't depress you enough, measure the 12VDC amps of a standard incandescent reading light or a 12VDC RV type florescent fixture. Just a few hours of reading at night can blow through 40-50 amp hours. Laptops can draw >20 amps @12VDC. A few hours writing your novel can easily drain more than 100 amp hours.

I have all LED lighting now. I've been picking up parts here and there and now have a good collection of stuff to light the interior of a Micro RV. It's even all color balanced to 5100k daylight spec. Perfect for photo editing. If you want a color balance to match warm white incandescent bulbs (3200k) you will be paying a performance penalty over ones that match halogen (4100k) or daylight (5000k to 5200k). I think they are only 70% or so as efficient. Even 4100k has a slight performance disadvantage over 5100k LED lamps.

I've also thought of putting in a secondary red LED light set for night time night light type use. That way it will be kinder on my night vision when I don't need to see all the colors properly.

Truck Lite has some LED based dome lights and strip lights that look promising in their online catalog. You'll have to find a truck stop or retailer to sell you the stuff as they don't do direct sales. Unfortunately they don't tell the lumen outputs of the lights. Looks like I'll be getting my tail and marker lights from them. My micro RV back is just large enough to trip the 80" (2032mm) width rule for lighting requirements on a "big" vehicle in the USA and Canada.

 

[James86004]

I have an evaporative cooler in my house. It works well when the humidity is below 50% or so. It is really nice when the humidity is below 20%, because when the air is that dry, my throat gets scratchy and my nose itchy. They don't make it muggy in those conditions at all - it fact, they make it more pleasant. Mold has been a non-issue, although I do replace the pads every year. I don't know how much water they use, but it is not enough that I notice on my water bill.

If you are going to spend a lot of time in the desert when it is hot, this may be worth checking out.

Here is a chart that give you the output temperature of an evap cooler. Find the ambient temp on the left side, and the ambient humidity along the top.

Lots of places sell the pads online.

 

[Mickldo]

You guys have been chatty haven't you.

Thanks for all of the info.

The boss is keen to fit AC to his new boat so I guess I'll have a guinea pig to do some testing on.

I think you have talked me out of a water cooled marine type AC unit just for the low water level thing. I am going to have to crunch some numbers to see if any kind of AC will be feasible.

I have always wanted a filtered, pressurised ducted air system so maybe a swamp cooler style AC system might be easy to integrate.

 

[dhackney]

I've also thought of putting in a secondary red LED light set for night time night light type use. That way it will be kinder on my night vision when I don't need to see all the colors properly.

I added a red LED night light system into our camper. Coming directly (do not pass Go, do not collect $200) from the sailing world full of night passages and accompanying navigation, I figured I'd use them a lot for the reason you cite.

I've used them two (2) times in 16 months.

Live and learn...

 

[Mickldo]

I added a red LED night light system into our camper. Coming directly (do not pass Go, do not collect $200) from the sailing world full of night passages and accompanying navigation, I figured I'd use them a lot for the reason you cite.

I've used them two (2) times in 16 months.

Live and learn...

One of our suppliers now has an interior LED light with a couple of different levels of illumination plus a red LED level. They look like a good light but like you say I don't reckon they would be used with the red very much. Maybe in the cab while driving but not in the camper.

 

[whatcharterboat]

Lots of places sell the pads online.

Thanks for all the info on the "swamp coolers" everyone. I'll have a google on the US sites.

 

[Mickldo]

I found this cool cruiser camper over on MUD.

The layout is a bit different to most of the campers this size I have seen before. All of the others, including my design, have had the bed longitudinally but this one has the bed mounted transversely. It frees up a lot of space at the back for the kitchen, etc.

In my design I wanted two slide out modules to give me enough space. With this design you'd use the same number of linear actuators but they wouldn't need the heavy duty slides as well.

I'd have to make the tray/camper a little wider than I had originally planned. Standard cruiser (75 series) tray width is 1920mm but allowing for the wall thicknesses of the camper I'd only have 1820mm bed length. Seeing I am 1830mm and I like a bit of extra room for the bed I reckon I'd need at least 2000mm tray width.

I'll have to measure my 105 to see how far out 2000mm will stick out. Hopefully I will be able to get away with just adding small mirror extensions.

At this stage this design looks good to me. I want to run through the design and see if it will be good for my wants/needs. What do you reckon?

 

[whatcharterboat]

At this stage this design looks good to me. I want to run through the design and see if it will be good for my wants/needs. What do you reckon?

Looks good to me too. Especially the rear entry. Any interior shots?

Hopefully I will be able to get away with just adding small mirror extensions.

Mick I'd really like to put together a camera system that replaced the mirrors altogether. And tap it in to the turn signal switch with possibly override buttons on either side of the steering wheel. So you end up with 3 or 4 cameras. A left, right, central rear and possibly even a close up rear over the tow ball/ We've done the close up camera before and it worked well but what do you think about the side cameras instead of mirrors?

Shame we had to bail early from the hillclimb. Good fun eh? John