Will the 5.3 gallon isotherm water heater take a lot longer to heat than the 4 gallon one?
Baby Shamu - 170 4x4
- Thread starter gltrimble
- Start date
gltrimble
Well-known member
Yes, the 20 liter Isotemp will take longer to heat up using the engine, D5, or the electric element. Once heated you have extra hot water but the disadvantage is the slower recovery time if you need more hot water. Also, the larger Isotemps do not fit under the van as cleanly as the 15 liter Isotemp.
gltrimble
Well-known member
Yes, I recommend the 15 liter Spa, It fits perfectly under the van on the driver’s side between the crossmembers.
gltrimble
Well-known member
I can’t say for sure if the Isotemp Slim will fit as cleanly. The Slim model is a little longer but smaller diameter compared to the Spa model. I believe the internals are identical. The Slim may hang down slightly below the van’s sheet metal seam weld.
smittylube
Active member
what size tires are you running in the pics from page 5 on?
Excellent work and design btw.
Excellent work and design btw.
gltrimble
Well-known member
In post #79 on page 4 I describe my fourth set of tires. These are Falken Wildpeak AT3 255/80-17 mounted on a set of Method 701 rims. These are 33”+ tires typically referred to as “Pizza Cutters” or “Skinnies”. Popular with the Jeep and Expedition crowd they provide maximum ground clearance, excellent traction, and the taller sidewalls help protect the rims from impact damage. My previous tires were KO2s and Cooper ST Max. Both had wear and noise issues. The Falkens offer exceptional off-road and snow traction with a quiet highway ride. They come with a 50k warranty and cost less than the previous tires. The local Discount Tire sold me 5 rims, 5 tires, and new lug nuts installed and balanced for about $2000 out the door.
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smittylube
Active member
Those look excellent.
@gltrimble
What is the floor you used? Looks like a vinyl sheet of some sort.
What is the floor you used? Looks like a vinyl sheet of some sort.
gltrimble
Well-known member
The floor and storage cabinets in the cargo area are covered in Loncoin vinyl flooring. It is held in place using Roberts 2310 adhesive. The floor in the forward half of the van is covered with “Pontoon boat” carpeting purchased from Amazon. I used a standard carpet adhesive from Home Depot.
TinManKC
Member
Gre
Great Build! Do you have details on the down draft fan used behind the range? Where does it exit? Thx!
gltrimble
Well-known member
I actually have yet to complete the install of the downdraft fan. Everything is in place except the exhaust port. I purchased a 3” diameter turbo fan from PKYS.com. I purchased an 18” x 2.5” black vent grill from West Marine. The fan is controlled by an overhead dimmer switch to vary the speed. The 3” diameter exit port is intended to go on the backside of my galley/sink cabinet but I have yet to complete the port. Of course this exhausting fan only works when the slider is open. For now I just turn on my Maxxair fan which sits directly over my range if cooking ventilation is needed. I could not vent my range top out the floor because my water tank sits below blocking access.
gltrimble
Well-known member
BATTERY HEATING SYSTEM
I finally had an opportunity to see how my battery heating system performs over multiple days in cold weather. We are in the Sierras for six days with temperatures so far ranging from 9 to 36F. In early 2020 I replaced my four AGM batteries with four 105 ah Lion Safari lithium batteries. I wrapped each pair of batteries with an 80 watt AC heating pad. The batteries were then wrapped with 3/4” of neoprene foam insulation. The heating pads are controlled by a pair of 12 volt Inkbird temperature controllers.
Initial results are promising. The Inkbirds are currently turning on the heating pads at 42F and turning them off at 45F. For the first two days at the local ski resort I parked in the sun alongside a dozen other vans. The solar production more than offset the energy use of the entire van which included the heating pads, refrigerator, and a small 350 watt space heater we used at lunchtime. So it was not immediately obvious how much energy the heating pads consumed in maintaining the battery temperatures.
One thing that became evident is the slow thermal response of the batteries. My Inkbird temperature probes are located between each pair of batteries while the heating pads surround most of the perimeter. When the heating pads turn off at 45F the batteries continue to warm up to 50F. I assume the opposite is true when the heating pads turn on at 42F, that the battery perimeter is in the 30s. I also have a pair of Victron Bluetooth temperature sensors on the top of the batteries and they do read colder temperatures compared to the Inkbirds.
I made some adjustment to my Victron solar controller when it stopped charging the batteries by lowering the acceptable charge temperature from 35F to 32F. The Victron temperature probe was seeing 33F even though the Inkbirds were registering much warmer temperatures. The batteries immediately accepted the solar charge telling me that the battery BMS was above 32F. I will likely fine tune my Inkbird settings to minimize my energy use but keep the batteries above 32F.
For nighttime use the van was connected to shore power so I could not get an accurate measure of the energy consumption. I might disconnect the shore power for one night to get a better estimate of the battery heating energy consumption.
I finally had an opportunity to see how my battery heating system performs over multiple days in cold weather. We are in the Sierras for six days with temperatures so far ranging from 9 to 36F. In early 2020 I replaced my four AGM batteries with four 105 ah Lion Safari lithium batteries. I wrapped each pair of batteries with an 80 watt AC heating pad. The batteries were then wrapped with 3/4” of neoprene foam insulation. The heating pads are controlled by a pair of 12 volt Inkbird temperature controllers.
Initial results are promising. The Inkbirds are currently turning on the heating pads at 42F and turning them off at 45F. For the first two days at the local ski resort I parked in the sun alongside a dozen other vans. The solar production more than offset the energy use of the entire van which included the heating pads, refrigerator, and a small 350 watt space heater we used at lunchtime. So it was not immediately obvious how much energy the heating pads consumed in maintaining the battery temperatures.
One thing that became evident is the slow thermal response of the batteries. My Inkbird temperature probes are located between each pair of batteries while the heating pads surround most of the perimeter. When the heating pads turn off at 45F the batteries continue to warm up to 50F. I assume the opposite is true when the heating pads turn on at 42F, that the battery perimeter is in the 30s. I also have a pair of Victron Bluetooth temperature sensors on the top of the batteries and they do read colder temperatures compared to the Inkbirds.
I made some adjustment to my Victron solar controller when it stopped charging the batteries by lowering the acceptable charge temperature from 35F to 32F. The Victron temperature probe was seeing 33F even though the Inkbirds were registering much warmer temperatures. The batteries immediately accepted the solar charge telling me that the battery BMS was above 32F. I will likely fine tune my Inkbird settings to minimize my energy use but keep the batteries above 32F.
For nighttime use the van was connected to shore power so I could not get an accurate measure of the energy consumption. I might disconnect the shore power for one night to get a better estimate of the battery heating energy consumption.
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Looks awesome, where did you get that bed frame? did you make it, is it sitting on L-brackets - is it strong enough?
gltrimble
Well-known member
I custom fabricated both the upper and lower aluminum bed frames and upper steel mounting rails. I estimate both upper and lower bed panels will support close to 500 lbs. Details of the bed panels and support rails can be found on this build thread. If I made the upper bed panels and rails again I would make a few changes including eliminating the center cross member in each bed panel, using 3/8” Baltic Birch rather than 1/2”, and replacing the steel bed rails with aluminum versions to cut down on weight.
@gltrimble Do you have any pictures or details of how you mounted your gray water tank on the front side of the tank? I assume you made some sort of custom hanger. Did you through bolt it to the floor? I am thinking of installing the same tank in the same spot.
gltrimble
Well-known member
Each front hanger on my gray tank consists of a short length of horizontal angle rivnutted to the factory crossmember. A second vertical piece of angle is welded to the horizontal angle. The lower allthread is welded to the side of the vertical angle similar to the rear supports. The first picture is the best I could find of the front supports. The positioning of the brackets should allow adequate clearance for the rear sway bar, about an 1”+. The rear brackets have a pipe spacer between the vertical angle and the factory tire hanger. I added a few other pictures to help visualize the layout. Some of the changes you see on the rear galvanized hanger bracket were done to accommodate my 33” tires and not for the gray water tank.
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