Parking Heater (Part 3)

Continuing the story of getting some heat into the bus while camping or parked. In Part 1, I touched on why I was doing this, how I arrived at the unit I got and what I needed to get to augment the kit so it was a viable install. In Part 2, I got into the planning, preparation and the beginning of the install. Today, I'm deep into it. This project is a little strange in that you can only go so far with one aspect before you need to get the others caught up. You'll see what I mean.

Heat Register

register mock-up

After all the destruction and time spent lying in puddles under the bus in my last post, I wanted something a little more creative and less wet. So, I moved inside the bus with a couple of cereal boxes from my recycling bin to mock-up a heat register. Judge me all you want, but Frosted Mini-Wheats are a great TV snack. Anyway, I set the heater in place and put a piece of cardboard underneath, roughly aligning with the steel grate opening. This is where science goes away and art comes in. I used the 3" vent that is supplied with the kit to give me perspective of where the register inlet would be. I considered the backside of the register could not touch the heater unit or there could be vibration noise. After a few cycles of test, measure, cut, test again, I arrived at a 3-dimensional cardboard model that fit, and should deliver the warmed air without leaking (see picture to the right).

To convert the cardboard model to something real, I just needed some HVAC flashing (be careful; it's sharp! Ask me how I know). I had intended to follow the same pattern I did with the trunk carpet in Oliver (see MGB Trunk Carpet Part 1), but it turned out my 3-dimensional model was really only suitable as a basis for taking measurements. The picture of the measurements is shared here in case someone else wants to do something like this. With dimensions in hand, I considered a few ways to go after it while I tried the measurements on another recycler-bound cereal box (Honey Nut Cheerios this time. Again, a very good TV snack). I cut one top/bottom and then the sides. The sides were simple rectangles 3" wide, spanning from the large outlet around to where the hose fit in. I concluded that I could do something very similar to the carpet on the speaker box, limiting the number of seams, and therefore cuts and extra tabs, etc.

register design

I decided to depend on DAP contact cement to hold the register together, and use no fasteners to hold it together. DAP can handle up to 180* and the heater specs say its output temp peaks at 135* so it should be a good match. Based on the website for the contact cement, I can bond the steel-to-steel with it. Then I'll go back around with HVAC tape inside the register so it is fully sealed. Considering that this is for functionality not a show-piece, I may even wrap the whole thing in that thin closed-cell insulation I have used around the various cars to help keep the hot air as hot as possible before it flows into the cabin.

With all of this in mind, I re-planned and drew a top, sides and bottom as 2 pieces on the HVAC sheet. That sheet was not quite large enough for all of it, so I created an interruption at the 3" hole, making for the smallest additional seam I could manage. The unit folded together along the 8" stretch that runs from the rear edge of the vent-to-bus to the edge furthest to the driver's side. This eliminated the longest seam. The other seams had small tabs that folded inside. I used my bench vise to help keep the lines straight as I folded the flat steel into a 3-dimensional box. The drawing can be seen in the picture to the right.

Once assembled, I test fit into the cabinet and then shifted focus again. I still need to integrate a 3" fitting / bib / inlet for the hose to attach to.

Fuel Pump Electrical

planning the cut

With a plan for the heat register, I looked at the wiring bundle. It's fairly simple. There are 3 plugs and 2 thick wires (12V supply and ground). The 3 plugs are relatively straightforward: there's a round one for the LED thermostat, a 2-pin rectangular one for the fuel pump and a large one for the heater. All three are keyed to only go one one way. The fuel pump cable is about 6 feet long, so I ran out most of it, and cut all but the last foot of it off the loom so I could thread it up into the bus from underneath. I drilled a 1/4" hole behind the auxiliary fuse box (driver's side under the rock-n-roll bed) and then slid under the bus. I plugged in the fuel pump and then ran the wire up over supports and then up through the hole, leaving very little slack, but not taught either.

The other wiring is all inside the bus. So, I climbed back inside the bus, and fished the fuel pump cable through the service opening near the rear driver tire well back into the rear of the fridge cabinet. I threaded the cable through to where the heater unit is being installed, and left things like that while I finished every thing else. I figured that I could decide to shorten wires once the heater is set, but doing it now, when the register isn't plumbed, the heater isn't bolted down, etc, was premature. It was around this point when I bolted the steel pan/sheet to the bottom of the heater. This seemed important (they wouldn't have included it otherwise). I figure it is some kind of heat shield or something.

Fuel Sourced
I ran a stretch of rubber/viton fuel line from the plastic tubing within the belly pan space to the inlet on the heater. I gave myself just enough hose so I could lift and tilt the heater to access the line. There is very little extra fuel line. The other end of the plastic fuel line for the heater is routed to the engine compartment. I intend to move the big clear plastic filter in the main fuel line down to the point where the main fuel line from the fuel tank enters the engine compartment, which is pretty much right next to the plastic line for the heater. Immediately after the filter, I will add the "T" for the heater. Rather than get into that now, I stayed with the electrical. Besides, it's cold and raining outside, and inside the bus was dry and out of the wind.

Main Power and Ground

heater grounded, but blurry

Power should have been the most straight-forward, but I just can't do simple, I guess. Consider that Hapy has 2 batteries during his in-use months: the main battery and the luxury battery. When we're camping, I'll want to source the heater off the luxury battery so we don't strand ourselves somewhere. When driving or when Hapy is off season, just parked in the driveway like now, I will want to run the heater off the only battery that's there: the main. So, with a plan to integrate a switch, I ran a 14ga (that's what came with the heater) wire from an unused battery-top 20A fuse along the familiar route: above the rear engine hatch, through the spare tire well and then forward into the little storage cabinet next to the rock-n-roll bed. From here, I ran a separate wire through to the heater, and spliced that into the harness. I had to pause that progress, since I don't have a switch handy, so I'll get back to this later. I will run a third wire from the switch to the luxury fuse box eventually. To keep things safe, I unplugged the 3-wire plug from the battery-top fuse box. I should also point out that the kit arrived with a 20A fuse, so the battery-top set-up is on-frame with the design.

For the ground, I looked around and through the various gaps in the cabinet for some exposed steel. I figured I could get at one of the side supports but that wasn't fruitful. So, I looked elsewhere. The cabinet floor had a 1" round hole just in front of where the heater unit was sitting. I think this was a drain hole for an ice-box option in the late-70's Westy. I was able to bore a hole into the steel floor there, scrape off the top paint and then steel-screw the ring terminal on the grounding wire (also 14ga) to the floor. It almost looks planned.

Intake

not an advert for Pepsy

At this point, I started to feel like this project was nearing its end. I needed to get the air intake attached to the air hose and the air hose attached to the air filter. The air hose is paper, and the aftermarket filter assumes that it is wrapping around the outside of something relatively firm, like a pipe. Those 2 characteristics don't align well. To remedy, I threaded the top of a soda-pop bottle into the foil/paper hose. Once it was all the way in, I cut the bottle off with a hacksaw. This provided the firm hose end that the air filter could attach to, so I forced it on and tightened it into place with a clamp.

I had intended to route this between the belly pan and the floor. Ya see, I have an old hole in the floor for the sink-drain when the '79 interior was installed, and I thought I would be able to maintain the air filter through that hole. I was mistaken, and probably ought to patch that hole. Anyway, the air intake hose provided in the kit was not long enough, and left me reaching around for it through that hole. There was no way I would be able to remove and re-install a filter that way. So, I was back to boring a hole. Similar to the exhaust hole, I used another drain hole as the center point for a hole saw. This hole is inboard of the exhaust hole by a few inches so the air hose will have a couple of extra bends in it. Recall that the intake hole was made smaller by the frame support. I decided to cut the steel floor between the holes so the intake could fit. Then, I sent the air hose up from the bottom. I decided to wait on attaching it to the underside of the belly pan until after I had the exhaust at least this far.

After all this, I got the comment from our old friend Hal. He indicated that the "air cleaner" is really nothing more than a noise baffle for the intake. He expressed concern that I might actually create an issue with a real air filter, so I removed the air filter. I will be wrapping the intake with some window screen or something to keep the flies out, but will not be using the air filter I got.

As usual, this post got long. So, I'm going to stop here. More next time and thanks, as always, for following along-

Pardon the Interruption

Brief today. The company I work for has a few annual training expectations. Among them are things like how to be secure, or how to conduct business or whatever. In an extreme case of irony, on the day of the impeachment vote in the US Senate, I had to take the annual business ethics training. Within this training, we must recognize the standards and sign that we agree to them, and will abide by them. There are 2 particular items that I thought were particularly interesting:

Anti-Bribery and Anti-Corruption
(the company) is committed to operating in an ethical manner and in compliance with all applicable anti-bribery laws and anti-corruption regulations. (the company)'s Anti-Bribery and Anti-Corruption policy reinforces our intention and obligation to act honestly and ethically in all our business dealings.

In simple terms, bribery is the offering, giving or receiving anything of value with the intention of inducing a person to act or to reward a person for having acted, while corruption is the abuse of someone's power or position for personal gain.

Bribery and corruption are not only against our company values, they are illegal and can expose both our employees and our company to fines, penalties, and reputational damage.

Whistleblower Provision
Reporting a suspicious or potentially illegal activity can be scary. You may wonder:
• What if I report an activity and I'm wrong? Will I get in trouble?

• What if I report an activity about my coworker and she gets into trouble? What will happen to me?

• What if my boss or employer goes after me for implicating them in criminal activity?

Luckily, there are laws in place to protect people — known as whistleblowers — who make a good faith report of suspected or detected misconduct that breaks federal or state rules, laws or regulations. While the actual laws differ by industry and country, they typically prohibit retaliation against the whistleblower.

In addition, we have specific provisions in our Code of Conduct that protect you should you report anything in good faith that you feel violates the law or our policies.


This all seems especially ironic today. On the day that I am being made aware of these rules, asked to sign that I understand and will follow them under penalty of loss-of-employment.... the Senate and the President are effectively side-stepping these same expectations.

What a wonderful world. Back to the bus next time-

Parking Heater (Part 2)

Today's post continues my process of introducing an experimental parking heater into the microbus. My main driver for this was our 4Peaks Music Festival experiences. Even though it is around the Summer Solstice, every year, the overnight temperature gets down into the mid-30F's (that's like 2*C for our non-US friends). That had caused us to us the Little Buddy heater a lot, heating up the tented-zone outside the bus while hanging out and then again inside the bus before going to bed. I figured if we had something dedicated to the bus, the little propane heater could just focus on keeping the hang-out zone tolerable. Aaand... the bus could be pre-warmed either while we were away at the stages or while we were sleeping.

Planning

blurry picture of test fit

It all starts with determining where you want to install it. I chose the old fridge cabinet because it had a false floor as well as a metal grate I could send the warmed air through. The air supply-side would just pull from under the cabinets and the bed; these are the coldest zones, so that should work great. The fuel and exhaust needed to get through the wood floor of the cabinet, the steel floor of the bus and the belly pan unique to the early 70's bus. I figured that I could source the combustion air from between the floor and the belly pan since there were multiple holes that would allow air to freely flow.

I will "T" off the diesel line from the main tank, and not use the kit-included second tank just for the heater. I figure I can introduce the "T" after the large clear filter so I won't need the tiny one shipped with the kit that does not look as hardy.

Preparation
Before I could start installing, I needed to remove the false-floor. I would have liked to reuse that floor, but the way it was installed made that impossible. So, with a 1" paddle bit on my drill, I bore multiple holes into the floor until I could smash it into pieces. Once the chunks were out, I cleaned up all the edges, removed the little bits of fasteners (staples and short wood screws) and shop-vac'd the thing out. Once it was gone, I could really evaluate my options. There were only so many ways the heater could go in, so I ended up with it just inside the outer wall and an inch or so in front of the rear wall (see blurry picture). This created the most room for the air intake while creating the least dramatic curve to the outlet hose. The picture doesn't really show it, but there are 1/2" gaps along the rear edge and a modest sized hole along the outer edge near the front. So, air will be able to enter without fighting a vacuum condition.

The outlet hose will still need to bend about 270* before entering a heat register that I will need to custom construct. For a mental picture, imagine a floor register in your house. It changes a 4" (or greater) diameter air hose into a rectangular shape. I could bore a 3" hole in the front of the cabinet, but I wanted this to be total stealth, and, honestly, this way was more fun. Most US housing is done with venting that is larger than 3" in diameter, so this would be a total fabrication.

Boring

fuel pump install

The heater unit delivers with a metal sheet that rests on the floor between the heater and whatever surface it is bolted to. I loosely taped the metal sheet to the heater and when I had set the heater where I wanted it, I pushed the metal sheet off, and I had a template for where the holes needed to go. I marked them with a pen, found the center-point of the holes and drilled a pilot hole in the wood cabinet floor at that center-point. I grabbed a hole-cutter for a 1-1/4" hole and drilled out the holes for the intake and exhaust. With a hand saw, I connected them together, making one single oval. I test fit the heater to make sure it dropped into the hole as intended.

With the same bit, I cut holes in the floor of the bus directly beneath the two I had just cut. The front hole went through beautifully. The rear hole, however, was partially blocked by a support running side to side. I'm a little concerned for how the air intake will need to adjust for that. With the holes in the floor, I could see one of the drain holes below and a little in front of the front hole I had just cut. So, I went underneath and bore a hole, using that drain as the center-point. I will route the exhaust out there.

Fuel
After a couple attempts, I arrived at routing the fuel from the front right corner of the engine compartment back along the stock fuel line path, then over the suspension support, along the emergency brake tube, past the nose of the transmission and then over to the passenger side along a cross support. To the rear side of this support nearest the passenger side frame rail, I attached the heater's fuel pump (see picture). The plastic fuel line would pass over the top of the frame rail and enter the space between the belly pan and the floor between the frame rail and the floor. Once I had the fuel line laid out and zip-tied in place, I installed the line to the pump with short sections of 4mm fuel line. I will caulk around where the fuel line passes into the belly pan space so vibrations do not slowly create a weakness in the line.

I figure I am maybe 1/3 done on this, so there's plenty left to do. I have the electrical, finishing the fuel, fabricating, installing and routing to a heat register, the air intake and exhaust. Then, I will test the heater, measuring the noise level and experiment with suppression ideas. I figure it'll be 2 more posts before it's all done at this rate.

As always, thanks for following along and more next time-