Given the costs of this project, and my higher priority yacht restoration project, I am putting this project on hold. I needed a truck camper immediately, to allow me to live next to my boat and avoid a lot of commuting. This winter I stumbled on a barn find camper, a 1998 Bigfoot that has been sitting in a barn for most of it's life. So I am making a few changes to that camper to make it off grid capable--all of which will be complete in the next few month so that I can focus my efforts on my boat.
In any event, I'm might fond of my Barth camper and plan to complete it at some point in the next few years. One nice thing about aluminum, it won't rot away. All my screen and storm glass is safely stored in the basement. I still plan to finish reinforcing the jack points so that I can move this camper to be location with more space around it where I can build a PVC and shrink wrap hut around it. I tend to have more time available in the winter and some sort of structure around it would give me more opportunities to work on it.
So long for now.
Tuesday, January 21, 2014
Thursday, November 28, 2013
Diesel Heater and insulation ramblings.
I purchased a diesel room heater for my apartment. It looks like it would work great in a camper and burns 1.44 gallons a day on low, putting out 5000 BTU's. This could be the perfect heater for me, although I still prefer wood as it is more available, cheaper, and better from a survival standpoint. If fuel costs go up and we know they will, then I'd rather preserve my fuel for mobility than heat. Still diesel/kerosene/fuel oil heating is nice, thermostatically controlled and can be left unattended, and with monitoring, left on over night. This could be an ideal cold weather camping heater.
I've also give some thought to improving the thermal break inside my camper. I'd like to make it still better insulated and one idea I had was to double up the thickness of the walls the further isolate the metal framing and siding from the interior. this can be done by adding another layer of framing offset from the present framing, and simply bonding rigid foam insulation to the interior with a modest amount of framing. Wall, floor and ceiling insulation would increase from R9 to R18. I could even go more for the ceiling if I raised to roof a foot, and have R27 on the roof. This is about what a well insulated house would have for insulation. It might be way overkill but I like the idea of burning a fire inside, heating a water tank and keeping the interior warm with the radiant heat of the water tank over night as the fire died out. I might find that the interior would need a much smaller heater, or that a wood stove with water tank buffer would keep the camper warm over night. Perhaps a diesel engine and cab heater might be enough to keep both my pickup motor warm, as well as my truck cab, and the camper warm. One thing is certain, this level of insulation means is I could keep my camper warm in tempetures well in to negative numbers like -30 -40 degrees.
Note there is a woman in Norther BC that heats a primitive camper with a large wood stove. She claims to stay warm in -40 deg weather with all the windows open. I am a bit skeptical.
If diesel is the heat source then I will need a second or third fuel tank to serve the heater. There is space in front of each wheel well of my pickup bed for a 24 gallon tank on each side. 48 gallons would give me a month of continuous heat on the low setting of a Toyotomi heater at a cost of $5 a day.
A few other random thoughts on staying warm in extremely cold climates:
For extremely low temperatures like this, an airlock door would be essential to keep the heat in and the cold out.
How well would a diesel heater server to keep the interior dry?
Windows and doors, with R value of 1 would be the weak points. With storm windows installed, would a wood stove be able to keep condensation from forming on windows? Would a diesel heater be able to prevent this? Would bubble wrap between the storm and primary windows help? Reflectix? Would my idea of rigid foam panels work well, or would condensation form behind them?
Should I remove some windows--like the front three and insulate this area to improve my camper insulation?
How do I make a thermal break at the windows? Use wood window trim? Butyl tape?
I've also give some thought to improving the thermal break inside my camper. I'd like to make it still better insulated and one idea I had was to double up the thickness of the walls the further isolate the metal framing and siding from the interior. this can be done by adding another layer of framing offset from the present framing, and simply bonding rigid foam insulation to the interior with a modest amount of framing. Wall, floor and ceiling insulation would increase from R9 to R18. I could even go more for the ceiling if I raised to roof a foot, and have R27 on the roof. This is about what a well insulated house would have for insulation. It might be way overkill but I like the idea of burning a fire inside, heating a water tank and keeping the interior warm with the radiant heat of the water tank over night as the fire died out. I might find that the interior would need a much smaller heater, or that a wood stove with water tank buffer would keep the camper warm over night. Perhaps a diesel engine and cab heater might be enough to keep both my pickup motor warm, as well as my truck cab, and the camper warm. One thing is certain, this level of insulation means is I could keep my camper warm in tempetures well in to negative numbers like -30 -40 degrees.
Note there is a woman in Norther BC that heats a primitive camper with a large wood stove. She claims to stay warm in -40 deg weather with all the windows open. I am a bit skeptical.
If diesel is the heat source then I will need a second or third fuel tank to serve the heater. There is space in front of each wheel well of my pickup bed for a 24 gallon tank on each side. 48 gallons would give me a month of continuous heat on the low setting of a Toyotomi heater at a cost of $5 a day.
A few other random thoughts on staying warm in extremely cold climates:
For extremely low temperatures like this, an airlock door would be essential to keep the heat in and the cold out.
How well would a diesel heater server to keep the interior dry?
Windows and doors, with R value of 1 would be the weak points. With storm windows installed, would a wood stove be able to keep condensation from forming on windows? Would a diesel heater be able to prevent this? Would bubble wrap between the storm and primary windows help? Reflectix? Would my idea of rigid foam panels work well, or would condensation form behind them?
Should I remove some windows--like the front three and insulate this area to improve my camper insulation?
How do I make a thermal break at the windows? Use wood window trim? Butyl tape?
Monday, January 7, 2013
Calculating Heat Loss in a Truck Camper
To calculate heat loss, you need to know a few things:
1) The square footage of all exterior surfaces, the top, walls, floors--every surface needs to be added up. I calculated my wall surfaces to be 552.5 square feet and windows to be at 25 square feet. I included two roof vents as windows.
2) The insulation value of these surfaces. Windows would lose more heat than an insulated wall. I plan to insulate my walls at R9 and expect them to be effectively less than this, due to thermal conductivity. So I'll reduce that to R8
3) The temperature difference you want to be able to keep warm. For example, I want to be able to keep the inside of my camper at 75 deg F in 20 degree weather. That is a difference of 55 degrees.
4) You need to know how to convert R-Values into U-Values. This is simple, U = 1/R.
Considerations for glass windows. While the R value is 1 for glass, adding window tint changes this 1.125 or a U Value of .89. Adding storm windows, another layer of glass increase the R Value to 2.125 (U Value for tinted windows and storm window is .47). Consider also that the roof vents would loose heat faster than glass. I will assume that I insulate these to at least as good a the windows for simplicities sake.
How to reduce heat loss further:
1) I could put solid R-6 insulation over the front windows. This is 10 square feet of area which would reduce my BTU loss substantially.
2) Another heat loss area is the door. I plan to improve the door seals. These are jalousie windows. I'll need to seal these with shrink film to reduce air leaks. Just like the front windows, installing insulation of these windows will help also.
These could reduce heat loss by 167 BTU per hour. So you can see, going to extra efforts does not radically reduce your BTU needs for heating. It is important to stop drafts that let it too much cold air, and shrink wrap film does that.
Most of the surface area will be insulated to R-9. I was worried heat would be conducted out of the camper on the wall studs. To achieve R-9, I need a thermal break like butyl tape or aerogel tape. This R value does not include wall coverings. Even an 1/8" of wood paneling would add a small but significant added insulation value. If I attached these panels without screws, the thermal break would be complete.
So the formula is T x U x sq ft for each windows and walls.
Here are my Calculations for heat loss:
Total Area: 552.5 sq feet insulated + 25 sq feet in glass
552.5 @ R 9 U-Value = (assume .111)
25 at R 1 U-value = 1
Delta T: I want 75 degrees inside with 20 degrees outside. Delta T = 55 degrees.
552.5 x .111 x 55 = 3798.44
25 x .47 x 55 = 646.25
Insulating front glazing and door glazing
15 x .16 x 55= 137.5
10 x .47 x 55 = 258.5
4194 BTU per hour
About 100,000 BTU’s per day.
That is a bit more heat loss than I'd like, but it is acceptable.
How to reduce heat loss further:
1) I could put solid R-6 insulation over the front windows. This is 10 square feet of area which would reduce my BTU loss substantially.
2) Another heat loss area is the door. I plan to improve the door seals. These are jalousie windows. I'll need to seal these with shrink film to reduce air leaks. Just like the front windows, installing insulation of these windows will help also.
These could reduce heat loss by 167 BTU per hour. So you can see, going to extra efforts does not radically reduce your BTU needs for heating. It is important to stop drafts that let it too much cold air, and shrink wrap film does that.
Most of the surface area will be insulated to R-9. I was worried heat would be conducted out of the camper on the wall studs. To achieve R-9, I need a thermal break like butyl tape or aerogel tape. This R value does not include wall coverings. Even an 1/8" of wood paneling would add a small but significant added insulation value. If I attached these panels without screws, the thermal break would be complete.
If I am tending a fire, I will likely be sleeping on the dinette. So I would be using the area over the cab for storage. If I block off the cab overhang, and place rigid insulation across that area, my heat needs would decrease by 94.5 sq ft and 578 BTU's per hour.
This would drop my total BTU needs to: 3616
Why am I making all these calculations? I want to chose a wood stove that will be sized such that it will keep my camper comfortable--if there is such a thing that is small enough. I may have to build a stove to suit my purposes. I want to keep the cost for heating it to a minimum, whatever the heat source is.
So it seems a 4000 BTU stove will keep it close to 75 in 20 degree weather, and a 5000 BTU stove will keep it at 75 degrees inside in weather colder than 20 degrees. If I take extra steps I can get by with a smaller stove, or else handle much colder weather. All this is good news. Even if I made a few mistakes on these estimates, it is clear that I can survive, even in sub zero weather, although the inside temperature goal may not be achievable. I should be able to handle weather down to 0 degrees F, as 55 deg F temperatures are cold but bearable.
Some practical considerations: Ever time I open the door, I will let in cold, cold air and all my heat out in a burst. My idea is to have a second door inside the camper. Either a pocket door that would close off the bathroom and shower area in the back, or else design a bathroom door to close two ways, one would close for privacy in the bathroom. The other would open the bathroom door and close off the hallway between the bathroom and shower dividing the kitchen dinette area from the bathroom shower area. This is called an airlock door. Only a smaller amount of heat is lost when the door is opened or closed. Stepping out quickly and closing the door quickly would help. Heat loss through the door would be an important consideration. Some sort of tarp hanging on the outside of the camper would help trap warm air inside the camper. Speaking of curtains. Insulated curtains could help reduce heat loss at windows. I know this all sounds extreme, but staying warm in a very cold situation demands these kinds of thoughtful considerations.
Bottom Line: What size BTU output would I need to keep my camper warm in cold weather? A small 3500 BTU heater would work ok. A bigger heater would work better but at the risk of making it too warm inside. I am setting a maximum size for my wood stove at 5000 BTU's. I expect there will be ways to lose excess heat. Opening doors, vents, and cracking windows. Looking at the market place there does not seem to be a stove sized this small. The Sardine stove seems to be the smallest I've seen. Some tent stoves I've seen are very light, but take full sized logs and while the BTU output is not listed, they are clearly stoves that can put out more heat than I need.
Lets take an extreme case. I am traveling in Northern Canada in the winter and get caught in a cold snap. Temperatures are -10 degrees F. But I'm prepared. I have my shower compartment filled to the ceiling with wood, charcoal briquettes and coal. Running my stove at maximum output, Lets say 5000 BTU's, what temperature could I keep the camper using all of the above tricks, but leaving the kitchen and dinette windows alone, and using the one ceiling vent, and one lower vent available for ventilation.
Equation 1: 458 x .111 x T = X 50.89 x T = X
Equation 2: 11 x .47 x T = Y 5.17 x T = Y
Equation 3: X + Y=5000 Substituting Equations 1 and 2 into equation 3 we get:
50.89T + 5.17T = 5000
56.06T = 5000
T = 5000/56.06 = 89.19
This means I could keep my camper at 80 degrees inside in -10 degrees outside temperatures. And it gives me a cushion for heat loss due to opening doors. Or windy conditions that increase heat loss.
I could scale back on the amount of fuel I put in for less cold conditions.
So under these conditions, how much fuel would I need and what would it weigh? Also, a small stove like this would need constant tending. What would be the burn time. While I don't have these questions answered yet, my search for a small stove lead me to multifuel stoves. These stove will burn wood and coal. I starting things that coal might be a good fuel for me. I would not need to much, but it would give me longer burn times, and perhaps last over night. An overnight burn would be nice. While I don't mind tending a wood stove during the day, I don't like the idea of getting up frequently to stay warm.
Coal: Coal produces 15,000 BTUs-per-pound. I would need one third of a pound an hour, at most. This seems like a modest amount of weight for the heat produced. So if I wanted to camp in 10 degree weather for one week, I would need only 56 lbs of coal? Deal. I'll take that. Realistically, I could burn wood during the day, and toss in paper bags with pre-measured loads of coal. To burn overnight, I'd need, at full output, 2.67 lbs of coal. I expect I could get a good fire going, toss in a nice supply of coal, dial my stove back some and get though the night, or perhaps get up no more than once if I ran it wider open. I have little experience with small stoves and no experience with coal fired stoves. I found the oak is about 6200 BTU's per pound. If this was a wood stove I expect I'd need to feed it every hour or two. I'd need about a .8 pound of oak an hour to stay warm, 135 lbs for a week heat. This does not seem like enough for that output, but these are the numbers I'm getting.
Water Heating: Some stoves come with a water coil for heating hot water. I like this idea tremendously, although it added complexity and the possibility of disaster if the water boils into steam.
Benefits:
1) It reduces the heat output of a stove because a portion of the heat goes to heating the water tank. That heat is not lost. It is stored and will re-radiate back into the camper.
2) A water coil and a water tank serve to moderate the heat in the camper. My pipes won't freeze if the stove runs out of fuel--not right away in any event.
3) If it is not too cold out and I want a clean burn with little smoke, I can put some of that heat into the water tank and still have enough heat output while producing a fun to watch fire.
Downsides:
1) Complexity needed to ensure the water does not boil and turn into steam would could cause and explosion.
By definition, a BTU is the amount of energy required to raise one pound of water one degree F.
But you have one gallon of water, which weighs approximately* 8.34 pounds. So, you'd need 8.34 BTU to increase one gallon of water one degree F. Assume a typical 6 gallon RV water tank, and ignore water in the pipes and stove. To raise the entire tank 1 degree would take 50 BTU's. That requires So if 2000 BTU's go to heating water. 2000 BTU's would raise the water temperature 40 degrees in one hour. Assuming the water starts at ambient temperature--say 70 degrees, the wood stove could take it to hot shower levels in one hour, and three hours would put it at 190 degrees. Time to shut off the stove because in a short while you will have to vent steam or purge your tank and refill with colder water to continue. Scary? If not you should be.
So I need to consider some fail safes. One option is to heat the main water tank, which will be around 50 gallons as well as the hot water tank. That would give me 56 gallons to be heated. No to raise this one degree would require 467 BTU's. So to raise this quanitiy of water from 70 degrees to 105 degrees (comfortable shower temperature) would require 16346 BTU's and 8 hours. I'd say that is safe provided thermostats and alarms can be attached that will warn of any problems.
No pump would be needed if the water tank was above the stove. My plan calls for putting the water tank below the stove. So a pump failure would be a disaster. All this is interesting, but it is unlikely I'll be heating water with a wood stove unless it is a tank sitting on top without any plumbing.
Availability:
The smallest marine stoves I could find put out 6500 BTU's on low. A diesel heater this size burns 1.29 gallons a day. At $4.50 a gallon for diesel that would cost $5.80 per day, and 38 gallons or $174 a month if I ran it continuously. That is pretty cheap! And easy.
The smallest wood/solid fuel stove puts out between 3000 and 8000 BTU's and used very small pieces of wood, or a handful of charcoal briquettes.
A propane vented stove would produce 5500 BTU's and burn fuel at a cost of $4.80 day. About one 20 lb tank every 140 hours.
So it seems I over analyzed things. The best benefit of insulation seems to be for cooling not heating as most stove put out more heat than I need. It is clearly of benefit to be well insulated as my heating needs will be modest, even in cold weather.
At these insulation values, I'd have to consider heat produced by people and dogs in the camper, heat generated by cooking and lighting. The net result is very little heat will be needed to heat this camper. A candle or two might be enough to keep it warm in mild conditions or a propane cook stove left on would keep it warm in mild weather.
1) The square footage of all exterior surfaces, the top, walls, floors--every surface needs to be added up. I calculated my wall surfaces to be 552.5 square feet and windows to be at 25 square feet. I included two roof vents as windows.
2) The insulation value of these surfaces. Windows would lose more heat than an insulated wall. I plan to insulate my walls at R9 and expect them to be effectively less than this, due to thermal conductivity. So I'll reduce that to R8
3) The temperature difference you want to be able to keep warm. For example, I want to be able to keep the inside of my camper at 75 deg F in 20 degree weather. That is a difference of 55 degrees.
4) You need to know how to convert R-Values into U-Values. This is simple, U = 1/R.
Considerations for glass windows. While the R value is 1 for glass, adding window tint changes this 1.125 or a U Value of .89. Adding storm windows, another layer of glass increase the R Value to 2.125 (U Value for tinted windows and storm window is .47). Consider also that the roof vents would loose heat faster than glass. I will assume that I insulate these to at least as good a the windows for simplicities sake.
How to reduce heat loss further:
1) I could put solid R-6 insulation over the front windows. This is 10 square feet of area which would reduce my BTU loss substantially.
2) Another heat loss area is the door. I plan to improve the door seals. These are jalousie windows. I'll need to seal these with shrink film to reduce air leaks. Just like the front windows, installing insulation of these windows will help also.
These could reduce heat loss by 167 BTU per hour. So you can see, going to extra efforts does not radically reduce your BTU needs for heating. It is important to stop drafts that let it too much cold air, and shrink wrap film does that.
Most of the surface area will be insulated to R-9. I was worried heat would be conducted out of the camper on the wall studs. To achieve R-9, I need a thermal break like butyl tape or aerogel tape. This R value does not include wall coverings. Even an 1/8" of wood paneling would add a small but significant added insulation value. If I attached these panels without screws, the thermal break would be complete.
So the formula is T x U x sq ft for each windows and walls.
Here are my Calculations for heat loss:
Total Area: 552.5 sq feet insulated + 25 sq feet in glass
552.5 @ R 9 U-Value = (assume .111)
25 at R 1 U-value = 1
Delta T: I want 75 degrees inside with 20 degrees outside. Delta T = 55 degrees.
552.5 x .111 x 55 = 3798.44
25 x .47 x 55 = 646.25
Insulating front glazing and door glazing
15 x .16 x 55= 137.5
10 x .47 x 55 = 258.5
4194 BTU per hour
About 100,000 BTU’s per day.
That is a bit more heat loss than I'd like, but it is acceptable.
How to reduce heat loss further:
1) I could put solid R-6 insulation over the front windows. This is 10 square feet of area which would reduce my BTU loss substantially.
2) Another heat loss area is the door. I plan to improve the door seals. These are jalousie windows. I'll need to seal these with shrink film to reduce air leaks. Just like the front windows, installing insulation of these windows will help also.
These could reduce heat loss by 167 BTU per hour. So you can see, going to extra efforts does not radically reduce your BTU needs for heating. It is important to stop drafts that let it too much cold air, and shrink wrap film does that.
Most of the surface area will be insulated to R-9. I was worried heat would be conducted out of the camper on the wall studs. To achieve R-9, I need a thermal break like butyl tape or aerogel tape. This R value does not include wall coverings. Even an 1/8" of wood paneling would add a small but significant added insulation value. If I attached these panels without screws, the thermal break would be complete.
If I am tending a fire, I will likely be sleeping on the dinette. So I would be using the area over the cab for storage. If I block off the cab overhang, and place rigid insulation across that area, my heat needs would decrease by 94.5 sq ft and 578 BTU's per hour.
This would drop my total BTU needs to: 3616
Why am I making all these calculations? I want to chose a wood stove that will be sized such that it will keep my camper comfortable--if there is such a thing that is small enough. I may have to build a stove to suit my purposes. I want to keep the cost for heating it to a minimum, whatever the heat source is.
So it seems a 4000 BTU stove will keep it close to 75 in 20 degree weather, and a 5000 BTU stove will keep it at 75 degrees inside in weather colder than 20 degrees. If I take extra steps I can get by with a smaller stove, or else handle much colder weather. All this is good news. Even if I made a few mistakes on these estimates, it is clear that I can survive, even in sub zero weather, although the inside temperature goal may not be achievable. I should be able to handle weather down to 0 degrees F, as 55 deg F temperatures are cold but bearable.
Some practical considerations: Ever time I open the door, I will let in cold, cold air and all my heat out in a burst. My idea is to have a second door inside the camper. Either a pocket door that would close off the bathroom and shower area in the back, or else design a bathroom door to close two ways, one would close for privacy in the bathroom. The other would open the bathroom door and close off the hallway between the bathroom and shower dividing the kitchen dinette area from the bathroom shower area. This is called an airlock door. Only a smaller amount of heat is lost when the door is opened or closed. Stepping out quickly and closing the door quickly would help. Heat loss through the door would be an important consideration. Some sort of tarp hanging on the outside of the camper would help trap warm air inside the camper. Speaking of curtains. Insulated curtains could help reduce heat loss at windows. I know this all sounds extreme, but staying warm in a very cold situation demands these kinds of thoughtful considerations.
Bottom Line: What size BTU output would I need to keep my camper warm in cold weather? A small 3500 BTU heater would work ok. A bigger heater would work better but at the risk of making it too warm inside. I am setting a maximum size for my wood stove at 5000 BTU's. I expect there will be ways to lose excess heat. Opening doors, vents, and cracking windows. Looking at the market place there does not seem to be a stove sized this small. The Sardine stove seems to be the smallest I've seen. Some tent stoves I've seen are very light, but take full sized logs and while the BTU output is not listed, they are clearly stoves that can put out more heat than I need.
Lets take an extreme case. I am traveling in Northern Canada in the winter and get caught in a cold snap. Temperatures are -10 degrees F. But I'm prepared. I have my shower compartment filled to the ceiling with wood, charcoal briquettes and coal. Running my stove at maximum output, Lets say 5000 BTU's, what temperature could I keep the camper using all of the above tricks, but leaving the kitchen and dinette windows alone, and using the one ceiling vent, and one lower vent available for ventilation.
Equation 1: 458 x .111 x T = X 50.89 x T = X
Equation 2: 11 x .47 x T = Y 5.17 x T = Y
Equation 3: X + Y=5000 Substituting Equations 1 and 2 into equation 3 we get:
50.89T + 5.17T = 5000
56.06T = 5000
T = 5000/56.06 = 89.19
This means I could keep my camper at 80 degrees inside in -10 degrees outside temperatures. And it gives me a cushion for heat loss due to opening doors. Or windy conditions that increase heat loss.
I could scale back on the amount of fuel I put in for less cold conditions.
So under these conditions, how much fuel would I need and what would it weigh? Also, a small stove like this would need constant tending. What would be the burn time. While I don't have these questions answered yet, my search for a small stove lead me to multifuel stoves. These stove will burn wood and coal. I starting things that coal might be a good fuel for me. I would not need to much, but it would give me longer burn times, and perhaps last over night. An overnight burn would be nice. While I don't mind tending a wood stove during the day, I don't like the idea of getting up frequently to stay warm.
Coal: Coal produces 15,000 BTUs-per-pound. I would need one third of a pound an hour, at most. This seems like a modest amount of weight for the heat produced. So if I wanted to camp in 10 degree weather for one week, I would need only 56 lbs of coal? Deal. I'll take that. Realistically, I could burn wood during the day, and toss in paper bags with pre-measured loads of coal. To burn overnight, I'd need, at full output, 2.67 lbs of coal. I expect I could get a good fire going, toss in a nice supply of coal, dial my stove back some and get though the night, or perhaps get up no more than once if I ran it wider open. I have little experience with small stoves and no experience with coal fired stoves. I found the oak is about 6200 BTU's per pound. If this was a wood stove I expect I'd need to feed it every hour or two. I'd need about a .8 pound of oak an hour to stay warm, 135 lbs for a week heat. This does not seem like enough for that output, but these are the numbers I'm getting.
Water Heating: Some stoves come with a water coil for heating hot water. I like this idea tremendously, although it added complexity and the possibility of disaster if the water boils into steam.
Benefits:
1) It reduces the heat output of a stove because a portion of the heat goes to heating the water tank. That heat is not lost. It is stored and will re-radiate back into the camper.
2) A water coil and a water tank serve to moderate the heat in the camper. My pipes won't freeze if the stove runs out of fuel--not right away in any event.
3) If it is not too cold out and I want a clean burn with little smoke, I can put some of that heat into the water tank and still have enough heat output while producing a fun to watch fire.
Downsides:
1) Complexity needed to ensure the water does not boil and turn into steam would could cause and explosion.
By definition, a BTU is the amount of energy required to raise one pound of water one degree F.
But you have one gallon of water, which weighs approximately* 8.34 pounds. So, you'd need 8.34 BTU to increase one gallon of water one degree F. Assume a typical 6 gallon RV water tank, and ignore water in the pipes and stove. To raise the entire tank 1 degree would take 50 BTU's. That requires So if 2000 BTU's go to heating water. 2000 BTU's would raise the water temperature 40 degrees in one hour. Assuming the water starts at ambient temperature--say 70 degrees, the wood stove could take it to hot shower levels in one hour, and three hours would put it at 190 degrees. Time to shut off the stove because in a short while you will have to vent steam or purge your tank and refill with colder water to continue. Scary? If not you should be.
So I need to consider some fail safes. One option is to heat the main water tank, which will be around 50 gallons as well as the hot water tank. That would give me 56 gallons to be heated. No to raise this one degree would require 467 BTU's. So to raise this quanitiy of water from 70 degrees to 105 degrees (comfortable shower temperature) would require 16346 BTU's and 8 hours. I'd say that is safe provided thermostats and alarms can be attached that will warn of any problems.
No pump would be needed if the water tank was above the stove. My plan calls for putting the water tank below the stove. So a pump failure would be a disaster. All this is interesting, but it is unlikely I'll be heating water with a wood stove unless it is a tank sitting on top without any plumbing.
Availability:
The smallest marine stoves I could find put out 6500 BTU's on low. A diesel heater this size burns 1.29 gallons a day. At $4.50 a gallon for diesel that would cost $5.80 per day, and 38 gallons or $174 a month if I ran it continuously. That is pretty cheap! And easy.
The smallest wood/solid fuel stove puts out between 3000 and 8000 BTU's and used very small pieces of wood, or a handful of charcoal briquettes.
A propane vented stove would produce 5500 BTU's and burn fuel at a cost of $4.80 day. About one 20 lb tank every 140 hours.
So it seems I over analyzed things. The best benefit of insulation seems to be for cooling not heating as most stove put out more heat than I need. It is clearly of benefit to be well insulated as my heating needs will be modest, even in cold weather.
At these insulation values, I'd have to consider heat produced by people and dogs in the camper, heat generated by cooking and lighting. The net result is very little heat will be needed to heat this camper. A candle or two might be enough to keep it warm in mild conditions or a propane cook stove left on would keep it warm in mild weather.
Wood Stove Options
Good news: I found several very small multi-fuel stoves for sale in the UK. These are in the 3.5-5k BTU size range. That could be enough to over heat my camper if it is well insulated, but if I use the boiler loop I divert much of the heat to water and reduce the heat output. So I have a means of regulating the heat while burning hot, clean and efficiently.
Bad News: However, I made a mistake. These are 3.5-5 kW stoves, and put out up to 18,000 BTU's. Too big for my little camper.
The prices or these stoves are reasonable, albeit shipping could be painful. The problem being these stove weigh too much.
My concern is that I don't want a 150 lb stove flying through the air in an accident, or one too many bumps in the road.
The Sardine: The smallest US made woodstove I could find was the Sardine. It is a 35 lb stove with a cooktop, but not water coil. While it would be nice to boil water for heat, I suppose I can find another way to do that. This stove burns wood and charcoal. I suppose coal would work with a grate installed. Although air flow might prohibit this.
The enameled verison in green:
I like the idea of cooking on the Sardine. I like that it is small. And while the burn time will be shorter on a small stove, I'd rather have clean burns than smokey ones, which means I'll be lighting fires and most likely letting them go out at night. If it was really cold, I could sleep on my dinette bed--my plan for cold nights, and be close to the fire where it is easy to feed.
That looks tasty. As much as I like the enamel surface on these stove, I am concerned about the finish failing. I anticipate putting cast iron fry pans on top, and perhaps a stainless steel tea urn for heating up water. I like the idea of a stove doing double duty. And heating up water will also divert some of the heat from heating the camper to heating the water with some moderating effects on the heating cycle.
One thing I really want is the pleasant glow of a fire that I can see. There is an option for a glass side panel, which would work out well for me. The enamel feature is expensive, and I won't be using it near salt water, so plain painted cast iron with the glass panel will be the logical choice. I'd like to find out more about how enamel holds up before I decide.
The Tiny Tot: This is an even smaller stove. There are a few features and options, but the double cooktop version weighs 27 lbs. They recommend charcoal or coal to fire this.
It is an interesting stove. For a smaller application, it would be my choice. I don't think it would be very useful for cooking, but it would be useful for keeping warm and drying clothes. I may choose this in any case and install some rails around it to dry clothes. The price for one of these, would be much less than a Sardine, about half at $361 plus flue and heat shields.
Tent Stoves: Tent stoves are lightweight, designed to be taken apart and moved around easily. So this is something I could move outside in warm weather. In fact, some are so light that I could easily have two stoves, one for inside and one for outside. Tent stoves are designed to heat a tent with no insulation, and they do a good job and burn a lot of wood, and larger pieces of wood. With one of these I'd be baked until well done. I would certainly be able to handle any temperature, but I'd also be opening and closing windows constantly. There are some nice designs. None of them have glass doors or ports.
Here is one of my favorites. This one is made in Sweden, as I recall and made entirely out of stainless steel. The flue pipes fit inside the stove for travel. I don't know the price on this one, it is probably expensive.
This one is made out of Titanium and weighs only 8 lbs. I like the fact that it is so light. The smallest verision is not much bigger than the Sardine. It is about 6 inches longer with about the same size face. Titanium is more resistant to staining and heat than Stainless steel, and it can handle much higher temperatures than steel. It is a nice product, and might be my final choice. $660
This next one is made of steel and features a water reservoir with a spigot on the side--I'd prefer it was on the front, but that could be changed. It is called a twodog stove.
They make larger sizes. This was the smallest I could find. About $325. Putting a second water reservoir on would be another $90. The shelf is extra also. This is simple and effective, and more than enough to heat my camper.
All of these tent stoves are made of thin, light metal, so they heat up fast and cool down fast. They do one job--provide a lot of heat, and viewing pleasure is not part of it, unless the door is left open.
In any event, they do propose ideas like the side reservoir tanks that have merit and might work well with other stoves.
Self Built Stove: My final option is a design, copy or modify a design for a stove and build it myself. I like rocket stoves. They offer a clean method of burning with efficient use of wood. Other fuels can be used. I will probably build a rocket stove in any case. The question is, will I use it in my camper for elsewhere. One design issue is a self feeding stove. I've seen one rocket stove that was self feeding. While I'd like that feature, it does pose some risks that manual feeding does not. I like the idea of being able to leave my camper in the winter for a period of time and not worrying about pipes freezing. A better option might be to use water has a heat storage medium that would re-radiate the heat. Also, I could disable the normal water system in the winter season and use water stored in containers or in a heated insulated reservoir that could withstand freezing. The later seems like the best choice, and I could still have water in my camper once it was brought back up to temperature.
Theme Considerations: My boat theme is well suited for a wood or coal stove. These have long be traditional in boats. Both the Tiny Tot and Sardine fit this theme well.
Bad News: However, I made a mistake. These are 3.5-5 kW stoves, and put out up to 18,000 BTU's. Too big for my little camper.
The prices or these stoves are reasonable, albeit shipping could be painful. The problem being these stove weigh too much.
My concern is that I don't want a 150 lb stove flying through the air in an accident, or one too many bumps in the road.
The Sardine: The smallest US made woodstove I could find was the Sardine. It is a 35 lb stove with a cooktop, but not water coil. While it would be nice to boil water for heat, I suppose I can find another way to do that. This stove burns wood and charcoal. I suppose coal would work with a grate installed. Although air flow might prohibit this.
The enameled verison in green:
This is plan cast iron version with window that I probably will buy. It won't have the cheezy name etched into the glass. $1240
I like the idea of cooking on the Sardine. I like that it is small. And while the burn time will be shorter on a small stove, I'd rather have clean burns than smokey ones, which means I'll be lighting fires and most likely letting them go out at night. If it was really cold, I could sleep on my dinette bed--my plan for cold nights, and be close to the fire where it is easy to feed.
That looks tasty. As much as I like the enamel surface on these stove, I am concerned about the finish failing. I anticipate putting cast iron fry pans on top, and perhaps a stainless steel tea urn for heating up water. I like the idea of a stove doing double duty. And heating up water will also divert some of the heat from heating the camper to heating the water with some moderating effects on the heating cycle.One thing I really want is the pleasant glow of a fire that I can see. There is an option for a glass side panel, which would work out well for me. The enamel feature is expensive, and I won't be using it near salt water, so plain painted cast iron with the glass panel will be the logical choice. I'd like to find out more about how enamel holds up before I decide.
The Tiny Tot: This is an even smaller stove. There are a few features and options, but the double cooktop version weighs 27 lbs. They recommend charcoal or coal to fire this.
It is an interesting stove. For a smaller application, it would be my choice. I don't think it would be very useful for cooking, but it would be useful for keeping warm and drying clothes. I may choose this in any case and install some rails around it to dry clothes. The price for one of these, would be much less than a Sardine, about half at $361 plus flue and heat shields.
Tent Stoves: Tent stoves are lightweight, designed to be taken apart and moved around easily. So this is something I could move outside in warm weather. In fact, some are so light that I could easily have two stoves, one for inside and one for outside. Tent stoves are designed to heat a tent with no insulation, and they do a good job and burn a lot of wood, and larger pieces of wood. With one of these I'd be baked until well done. I would certainly be able to handle any temperature, but I'd also be opening and closing windows constantly. There are some nice designs. None of them have glass doors or ports.
Here is one of my favorites. This one is made in Sweden, as I recall and made entirely out of stainless steel. The flue pipes fit inside the stove for travel. I don't know the price on this one, it is probably expensive.
This one is made out of Titanium and weighs only 8 lbs. I like the fact that it is so light. The smallest verision is not much bigger than the Sardine. It is about 6 inches longer with about the same size face. Titanium is more resistant to staining and heat than Stainless steel, and it can handle much higher temperatures than steel. It is a nice product, and might be my final choice. $660
This next one is made of steel and features a water reservoir with a spigot on the side--I'd prefer it was on the front, but that could be changed. It is called a twodog stove.
All of these tent stoves are made of thin, light metal, so they heat up fast and cool down fast. They do one job--provide a lot of heat, and viewing pleasure is not part of it, unless the door is left open.
In any event, they do propose ideas like the side reservoir tanks that have merit and might work well with other stoves.
Self Built Stove: My final option is a design, copy or modify a design for a stove and build it myself. I like rocket stoves. They offer a clean method of burning with efficient use of wood. Other fuels can be used. I will probably build a rocket stove in any case. The question is, will I use it in my camper for elsewhere. One design issue is a self feeding stove. I've seen one rocket stove that was self feeding. While I'd like that feature, it does pose some risks that manual feeding does not. I like the idea of being able to leave my camper in the winter for a period of time and not worrying about pipes freezing. A better option might be to use water has a heat storage medium that would re-radiate the heat. Also, I could disable the normal water system in the winter season and use water stored in containers or in a heated insulated reservoir that could withstand freezing. The later seems like the best choice, and I could still have water in my camper once it was brought back up to temperature.
Theme Considerations: My boat theme is well suited for a wood or coal stove. These have long be traditional in boats. Both the Tiny Tot and Sardine fit this theme well.
Friday, January 4, 2013
RM 2554 Americana
I am thinking this might be a good replacement refrigerator for my camper.
Link: 42" refrigerator
I have a 60" model that is nearly new I could use, but it won't fit except in the location of my propane and battery locker, which seems like too much work to make fit. Then too, I'd need a new solution for the battery and propane.
Also, the camper is set up for a fridge in the old location.
Corner Damage and Shower Toilet Planning
This top corner was crushed. I was hoping I could pop it back out and reuse the old piece. Now I am not so sure. I'll try but it might split. It will be easier to make a new one if I have this somewhat in the right shape. We'll have to see how it comes out.
Here is the culprit. Lucky for me, only this cap was badly damaged. It looks like someone backed into a garage eve or something high up like that. Some of the other corners show some signs of damage. I also removed the other side in the back. Two areas in the front show minor damage also. I'm holding off on those until I finish the jack mounts.
This is the old bathroom located in the aft port corner. The toilet was in the middle of the shower and the sink was to the right. My plan is to put an Incinolet toilet here and a stainless steel yacht sink I have. It will be a bigger sink, so I may have issues making it fit. The shower will be separate and go on the other side. That complicates plumbing, but the incinerating toilet eliminates the need for a black water holding tank. For gray water I plan to filter it with charcoal and diatomaceous earth, and discharge it wherever I use it with a garden hose. Or drop it into a 5 gallon bucket to be disposed of. I may use diatomateous as a filter for fresh water. I would like to be able to pump fresh water from lakes and streams though an effective filter medium for drinking and bathing use.
This area was propane storage. Not any more. That will have to go outside under the camper on a storage frame. This area will be the shower. I'll have storage above. The shower will double as firewood storage down low and a hanging locker for wet clothes, or dry clothes. I don't plan to bring many clothes with me, most of which will be stored in locker up high on the starboard side. Port side will be food storage. The shower will have to extend out a bit. I'd like to keep the entry wide, but I don't want the shower to be too small. It will come out a few inches short of the door. To the left of this space shown in the photo will be my heater. I have still not decided exactly what sort of heater. As I mentioned in an earlier post, I'm leaning towards a small woodstove and either a diesel heater or a propane heater. The old furnace was so big, it should be easy to fit several types of heater in the area formerly occupied by the furnace.
Peeling Back Some of the Skin
All four corners of the jack points had damage. And this is the biggest stumbling block to acutally using the camper, and being able to move it around. Here are views from the outside with the curved corner skin removed. I will have to replace a Y shaped extrusion on both sides.
An inside view. You can clearly see the C-channel on this side. Their is a flange extending outwards on the top to make in an h shape like a chair lying on it's front legs with the back of the chair up. I can't find any of this material anywhere so far.
The design looks weak to me. Even without rotten wooden backing, it seems like this is a weak point on the camper.
This is a good view of the sort of damage I need to repair. I was hoping to find a h shaped extrusion to replace the entire piece. I have a few options here. One is to remove this piece, cut it in half and use the fresh pieces for the ends, with some reinforcing in the middle. Another is to hammer it flat with some backer steel and reinforce the outside with some angle aluminum. I would love to put in a heavier piece of square tubing and and angle bracket on the outside.
This front part looks a bit messed up. I have removed this and I found it to be ok--just slightly tweaked. I need to put a new plywood floor in there to make it perfect and bang it straight. The sheeting is torn in one spot and shows damage from rubbing against a pickup bed.
Here is a view with this panel removed.
An inside view. You can clearly see the C-channel on this side. Their is a flange extending outwards on the top to make in an h shape like a chair lying on it's front legs with the back of the chair up. I can't find any of this material anywhere so far.
The design looks weak to me. Even without rotten wooden backing, it seems like this is a weak point on the camper.
This is a good view of the sort of damage I need to repair. I was hoping to find a h shaped extrusion to replace the entire piece. I have a few options here. One is to remove this piece, cut it in half and use the fresh pieces for the ends, with some reinforcing in the middle. Another is to hammer it flat with some backer steel and reinforce the outside with some angle aluminum. I would love to put in a heavier piece of square tubing and and angle bracket on the outside.
This front part looks a bit messed up. I have removed this and I found it to be ok--just slightly tweaked. I need to put a new plywood floor in there to make it perfect and bang it straight. The sheeting is torn in one spot and shows damage from rubbing against a pickup bed.
Below you can see where the aluminum sheeting is torn. I have this entire piece removed and plan to replace it completely and use this scrap piece for repairs under the wings. 
Here is a view with this panel removed.
Subscribe to:
Posts (Atom)