Parking Heater (Part 4)

Picking up where I left off last time, I was in the middle of the install of one of those cheap eBay parking heaters that are a rip-off of those $1000US jobs. I have a partially constructed custom heat register, the fuel line run from the engine compartment through the fuel pump to the heater unit. I have holes bored for the combustion air intake and exhaust. Last, I have the unit grounded and the 12V source almost together. So, while lots of things are not done, they are all just a few steps away. I didn't quite finish it today.

Exhausting

making register

I had already worked the combustion air intake hose up through the holes from under the bus. This took a few trips in and out of the bus to get the hose to bend and not hang up as it passed through. If you have a helper, even a reluctant one, this is where s/he would really give lots of help for very little effort. With sufficient hose pushed through to the inside of the cabin (I gave myself about 6"), I switched to the exhaust. First, I slid the bendy stainless steel hose into the heat sleeve. The sleeve is 3' long, and it is much longer than the stainless steel exhaust hose/pipe; I will have extra. I got the sleeve as tight around the pipe as I could and slid it up through the holes from under the bus. These holes were more aligned and a little larger than the intake, so it went through with little fanfare.

Once through, I could start connecting the air and exhaust to the heater. The air hose was more willing to be managed, and connected without much effort. The exhaust, however, took some doing, but I got it on, and the sleeve pulled all the way to the top, and then clamped the pipe and sleeve to the heater output with one clamp. In the process, the fuel line popped off, so it needed to be re-attached. For now, the exhaust and intake pipes are laying on top of a car-ramp so they aren't sitting on the pavement in the rain. I'll button them up to the underside once everything is working and after the noise experiments indicate what muffler solution to use.

Heater In

heater in

With the underside connections to the heater all buttoned up, I was ready to press the heater into place. First, I set the heater above the hole and pushed a little bit. Say, 10 pounds of pressure. Then, similar to the run-around I did for the air intake, I got under the bus and tugged on the hoses a little bit. Again 10 pounds of pressure or less. This took some of the excess bends out so I could then press the heater home from inside. I checked again from below just to be sure. I then attached the unit to the bottom of the cabinet with a pair of wood screws and then tried to shake the heater. It wouldn't budge.

Fueled
Next, I needed to complete the connections for the fuel. I had intended to locate the "T" close to the front (front is front) of the engine compartment, but once I got in a position to work on it, I made a small change. The large clear filter was already in a fairly good space, and I figured that I could fit the "T" just downstream of the filter without cutting any fuel hoses. I took the "T", pressed on a short (2" long) stretch of hose on one end, and a 2" stretch of 4mm hose on the small part of the "T". I clamped the other end of the 4mm hose to the trimmed end of the heater fuel line. Then, I squeeze-sealed-off the hose between the clear filter and the large filter with a vice-grip. I was now able to remove the line from the clear filter and then quickly connected the short stretch of hose from the "T" to it. To the other end of the "T" I connected the vice-gripped line. All clamps were snugged down and then I removed the vice-grip, but fuel didn't really move around. The net result has fuel leaving the small clear filter and immediately enter the "T" fitting. The large end of the "T" continues on to the Caterpillar filter while the small (4mm) end of the "T" routes to the heater.

Priming

foamed and screwed

I should note that the picture in the last post of the fuel pump needed to change. The directions give no indication of the fuel flow direction, and that pump is one-directional, pulling towards the end which shares the electrical plug. That's the case with mine and while they may not all be the same, my viewings on YouTube of the little heater professor (John McK) implies that they are all the same. I was also alerted (again by Hal) about the orientation of the fuel pump in my post a few weeks back. So, I re-checked it, and he was right, I had it practically horizontal, and they need to be approaching vertical for the fuel to lubricate the piston inside the pump and for the little bubbles created during the pumping to float up into the heater. I disconnected the heater-side from the pump, shifted things around, and re-connected.

I left the fuel line at the supply-side of the fuel pump disconnected, however. To this line, I connected the Mity-Vac to fill it with fuel. Once the Mity-Vac jar was steadily filling, I stopped the vacuum and quickly reconnected the line to the pump. I checked the clear filter in the engine bay and it was full, so we should have a nice tight system now.

Complete Heat Register
When I last touched the heat register, it was a box, but it needed to be sealed and it still needed a 3" pipe connection. I got a 4" connector from Home Depot, and cut it open. I could have probably used some basic flashing, but thought the dimples and wrinkles would help hold the air hose on. I fit the cut connector into the hose, marked with a pen and then cut the connector so it fit a 3" diameter hose. I also cut about 1-1/2 inches off the end to make more maneuvering room in the cabinet. I fit the connector into the register from the inside, and pushed the seating tabs down. Once set, I used metal HVAC tape on all of the seams on the register, including the connector. You can see the finished result in the top picture.

register completed

My rough forming of the register resulted in the outlet not being completely flat. I tweaked it for a few minutes and got it close, but I knew I couldn't get it perfectly flat. To resolve, I put a thin strip of foam along the edge which would be pressed against the cabinet. Then, I threaded one screw per side through the register edge to hold it to the cabinet. I took it out to the bus, and pressed it into service.

Last for the heat outlet, I needed to run the air hose from the heater to the register. This was relatively simple. I laid out the hose to check length, cut it with a pair of scissors, and clamped it in. It took some wrestling.

Finish Electrical
With the fuel ready and the heated air routed, all that was left was connecting the final electrical bits. First, I completed the wiring from the fuel pump. By now, the switch I had ordered had arrived, so the rest was just as easy. I connected the center post to the heater supply-side and the fused 12V from the main battery to one of the outer posts. Then, I plugged in the controller and the heater.

Tests

The moment had arrived. After charging the battery, I flipped the switch, and heard the fuel pump fire up. Then, the fan on the heater started. Cool air blew through the register and out onto my boots. I felt the air flow and there was positive, consistent air movement all along the grate. But, the air was not warming up. Huh. So, I tried to figure out the interface, and I really couldn't. I knew from John McK's videos that the way you changed the temperature was to increase the speed of the fuel pump, so I messed with that a little bit. Turned out, I was just impatient. Once the glow plug was up to temp and fuel had made it down that last stretch of hose from the pump, the diesel started to fire and I started to get heat. Curious about the noise, I checked the driver side of the bus. It sits below 65dB, floating up and down depending on the fuel pump speed. At the lowest setting, my little phone app decoded the dB to "quiet house". At the mid-setting (3.3 on the pump speed) is decoded to "quiet street". This is without a baffle on the air intake, and the exhaust without any muffling while I was standing, semi-stooped over with a phone a few feet away from the hose ends. More on how these ends are dealt with next time.

Thanks, as always, for following along--

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-