My last hurdle - condensation

[luthj]

In conditions of 50F and 25% humidity, the average person excretes about 20ml per hour of water. In colder or dryer temps, this increases even further. That is about 1 cup of water overnight. Now add moisture from sweating, wet gear, or cooking to that. How much water can the silica desiccants carry? The graph below indicates that at 100% relative humidity you would need 570 grams of desiccant to absorb 200 grams of water. Thats a pretty significant amount.

 

[TantoTrailers]

I think the moisture absorbents are great for storage and long term moisture control, but for living use, the formula is dry heat + fresh air in + ventilation of moist air out. Once I have the diesel heater which is strictly dry heat I can test the fresh air/ventilation piece to determine if ventilation only will be enough or if cracking a window for fresh air will also be necessary. The heater will be fed by a mixture of fresh air and recycled air.

 

[shade]

I think the moisture absorbents are great for storage and long term moisture control, but for living use, the formula is dry heat + fresh air in + ventilation of moist air out. Once I have the diesel heater which is strictly dry heat I can test the fresh air/ventilation piece to determine if ventilation only will be enough or if cracking a window for fresh air will also be necessary. The heater will be fed by a mixture of fresh air and recycled air.

I think your heater will take care of the problem. With heat, ventilating more in cold temperatures isn't as much of an issue, either.

 

[chet6.7]

My cabin space is 6.5' long x 5' wide x 4' tall. I think 2kw will suffice and I do not plan on shutting off the heater until the morning, so it should not be cycling on/off at all. I will use a combination of exhaust vent and windows to control temp if things get too warm in there.

Looking forward to see you results with the 2kw.The area you are trying to heat is about the same as mine currently,I do wonder, if I am able to swing the FWC Project M,if the 5kw would be the better choice.

 

[TantoTrailers]

The 5k was pushing a lot of heat at its lowest setting, fine to warm up but it would build up fast if it’s 20 or 30 F out I think. I have insulated floor and ceiling so my heat retention should be ok. I’m hoping I can run the 2k a bit more in its sweet spot where it’s supposedly not building soot. It arrives tomorrow (hopefully) so I will get it hooked up in place of the 5k in the all in one case and see how it performs.

 

[rajacat]

My 3 KW unit arrived today in a marginally adequate box. Only one dent in the heater housing. I think I'll scrap the housing and install the unit as components. It would be very difficult to lead the intake/exhaust tubes otherwise. Hmm...I better bench test it first.

 

[TantoTrailers]

Yea the promises of my 2kw arriving have come and gone...new promise if Friday...no worries though I’m still waiting on the new tank which will arrive money

 

[TantoTrailers]

Well my "2kw" heater arrived and it is labeled as a 3kw...its significantly smaller than the 5kw so I think this should be fine. Im waiting for the fuel tank to arrive so I can make sure everything will Tetris fit in this space before drilling any holes. I need to pull apart the harness for this heater because the pin configuration is different.

 

[TantoTrailers]

As usual new hoops to jump through. I got the pin out correct but the 5kw controller may not be compatible with this particular heater. It takes about 5-10 seconds for the screen to come on then I’m getting an error on screen regarding the wiring. Need to look deeper into this...I should just find the 2kw kit that uses the same controller as the 5kw...

 

[rajacat]

I'm considering using kerosene and carrying along an extra fuel pump. They're only ~$25.

 

[TantoTrailers]

Oh I will definitely have a spare controller and pump as well as some other odds and ends for this part of the rig. Incidentally I won an offer for a 2kw that sits in an aluminum housing that uses the same controller as the 5kw. I’m wondering if the aluminum housing will get warm after all night of running where the plastic did not...

 

[luthj]

The fuel pumps are dead simple and reliable. You should consider a spare filter cup if the pump has one. Typically the filter is a small thimble located underneath the pump inlet fitting. You should see if the heater can be controlled with a simple potentiometer. The Espar and some webasto units support a simple ~5k pot to set the desired temperature, and a switch to enable/disable heating.

 

[TantoTrailers]

I received the fuel tank today and it will fit where it needs to go but a bit too tight for my liking....thats life sometimes! It will have to do. I will plan better for the 2.0 build. I also got a self activating fire extinguisher since now I have flammable liquids involved. Hopefully this doesnt self activate accidentally on an off road adventure. It will be mounted to the "ceiling" of that galley space right above the tank and heater. Once the new 2kw heater arrives Thursday I can get things installed but I am being left with 0 room for error with my campout the following day on Friday. If push comes to shove the 5kw that I have had all along is going in as at that point I will consider it fate; I know it runs well, heats well, sips fuel, and is silent (i have read and seen a lot of videos where the fan motor has an audible whine to it...mine is just the sound of the air passing through). Coincidentally the dimensions for the 3rd heater, the second 2kw I ordered, are about the same as the 5kw I have now so I hope that was just a misprint and Im actually getting the smaller heater this time around. Total crapshoot it seems.

 

[luthj]

The heaters themselves (if fueled with kero/diesel) are a very low fire risk. Much lower than the typical RV wiring, Ha! I have never heard or seen a single fire incident with any of them. Outside of a couple burned harnesses from improper installs. The gasoline models are only slightly higher risk if the fuel is stored inside (which would be pretty rare due to the smell).

You may consider getting a timer/program control for the heater. One of my favorite features of my Espar timer/controller, is that I can set a program. So the heater will come on 30 minutes before I need to get out of bed (or in the middle of the night).

 

[rajacat]

The fuel pumps are dead simple and reliable. You should consider a spare filter cup if the pump has one. Typically the filter is a small thimble located underneath the pump inlet fitting. You should see if the heater can be controlled with a simple potentiometer. The Espar and some webasto units support a simple ~5k pot to set the desired temperature, and a switch to enable/disable heating.

I'm mostly concerned with kerosene providing less lubricity than diesel thereby decreasing the longevity of the pump. If it last several years of very moderate service and then fails that will be good enough for me. I'll accept less longevity for cleaner burning.