My Engine Heater

[bob865]

17 hours ago, Yetti said:

and possibly the cabin too?

I have considered getting a T fitting to put air into the cabin and into the cowling so I get into a warm plane too.  It's always an option.  Just more hardware to transport though.

[bob865]

16 hours ago, jaylw314 said:

Also, I'm not clear on how the heater works--does it actually burn the diesel and use the exhaust gas, or does it convert it into electricity and then heat an electric element?

Like @larryb said, they are separate.  I will try to take a picture of the back of the box when I get home so you can get a better idea.

[Andy95W]

17 hours ago, DonMuncy said:

I fitted my plug-in heater with a 4 inch semi-flexible (think clothes dryer) hose. I stick it up into the cowl flap and crack the oil filler door on top to allow some movement of air.

I actually get better results by keeping the oil filler door closed and a blanket in top.

It seems like the hot air rises from the heater tube in one cowl flap and then the cold air is displaced to exit from the other cowl flap, maybe?

[thinwing]

Or simply rises thru any gaps around the cylinders and out the intakes...blanket a good idea

[DonMuncy]

55 minutes ago, Andy95W said:

I actually get better results by keeping the oil filler door closed and a blanket in top.

It seems like the hot air rises from the heater tube in one cowl flap and then the cold air is displaced to exit from the other cowl flap, maybe?

You are probably right. I haven't used mine enough to get any worthwhile experience.

[jaylw314]

2 hours ago, Andy95W said:

I actually get better results by keeping the oil filler door closed and a blanket in top.

It seems like the hot air rises from the heater tube in one cowl flap and then the cold air is displaced to exit from the other cowl flap, maybe?

That would make sense for a 60W light bulb or small heater, no sense opening up the oil filler door.  The warm air will simply rise to the top, and cooler air will come out the other cowl flap.

For a more powerful heater, I suppose it might be helpful to open the oil filler door to keep the accessory compartment from getting baked, but I imagine it'd have to be a pretty powerful heater!

[yvesg]

My propane setup produces twice yours, 35000 BTUs and it takes between 20 and 30 minutes to pre-heat when the OAT is -20C. I’ll post a picture when I get home. While the aircraft is at annual, I decided to replace the 4 inch pipe and some other fittings. Have been using it for a few decades and it never let me down.

Yves

[Andy95W]

39 minutes ago, jaylw314 said:

That would make sense for a 60W light bulb or small heater, no sense opening up the oil filler door.  The warm air will simply rise to the top, and cooler air will come out the other cowl flap.

For a more powerful heater, I suppose it might be helpful to open the oil filler door to keep the accessory compartment from getting baked, but I imagine it'd have to be a pretty powerful heater!

This is a great point- my heater is a fairly small one - 1500W.  I use it to supplement my Reiff on really cold Michigan days.

 

[Yetti]

9 hours ago, yvesg said:

 when the OAT is -20C.

Yves

I am just going to put it out there that if the OAT were to ever hit that, I am packing and moving further south.

[yvesg]

Here is the device:

 

[bob865]

On 2/14/2018 at 8:48 PM, yvesg said:

Here is the device:

 

That kind of heater requires to be plugged in correct?  That's why I went the route I did.  I don't have a place to plug a heater in.  Otherwise I would have chosen some electric options.

[steingar]

Congrats to the OP, that is a really clever set up.  That said, I wouldn't fly it inside the airplane on a bet.  Sorry, that fuel container doesn't look like it would survive a trip to high altitude.  I could be wrong, just what it looks like.  I take fuel to any altitude its in a camping bottle built to do so.  Putting anything flammable in the aircraft gives me the willies.  During the winter in the North most of my stops are sufficiently short that the engine doesn't cool down, especially with my cowl plugs in it.  

Actually, I have a little heater from aircraft heaters.com.  I usually carry it and an extension chord during the winter, and if I do stay for awhileI plug the thing in.  I've yet to travel to an airport where I couldn't find some electrical power. If I'm going to stop for that much longer I pony up for a heated hangar.

[yvesg]

8 hours ago, bob865 said:

That kind of heater requires to be plugged in correct?  That's why I went the route I did.  I don't have a place to plug a heater in.  Otherwise I would have chosen some electric options.

This one requires 12V for the fan. I replaced the 120V AC by a car heater fan motor. I usually carry an emergency battery power pack which has cig lighter outlet. I made the cable long enough that I could reach the one in my car. However they do sell such devices with integrated batteries like this one: http://www.mrheater.com/35-000-btu-hero-heater.html

Yves

[Awful_Charlie]

Thought I'd add to this, as thanks to the original idea, I went ahead on one of these.

The only power I have at my home 'drome is via a generator, and I wanted something I could take with me too, as hangars for visitors can be quite difficult when touring. I also wanted something that could be used to eg heat a tent, or even potentially for working in the hangar.

Things I wanted over Bob's original design were less protrusions on the exterior, able to be left as well as used outside (less susceptible to rain), and possibly a greater autonomy. If it could be more rodent-proof that would be an advantage, as would making it resistant to spills (I think the smell of diesel/jet fuel/heating oil in a confined space particularly nauseating)

After getting the bits and starting to assemble, I wish I'd done more research before! In Europe, heaters like these are frequently found in boats and motorhomes, and sometimes the long distance trucks. They're often known by the trade name "Eberspacher" https://www.eberspacher.com/ where a D5 model equivalent from ebay could be had for less than USD250. The D5 uses up to 0.6 liters (a litre is near a dammit a quart) per hour foor a 5500W output

After the heater itself, a tool box from a local DIY store (expensive - this is Switzerland!, but at least I could see what was inside etc before buying), fuel tanks, batteries, charger and some odds and ends from a model shop (batteries for an RC model were more like the load profile than a motorcycle battery I thought), and a couple of evenings with a drill and knife.

Result:

Fairly standard looking toolbox from a distance (Oil cans for scale!)

On left, exhaust, charging socket and master switch, heater supplied control panel in the middle, thermometer stuck on the right

Air inlet is via hundreds of small holes drilled below the drip line of the lid that continue round the tool box

Hot air outlet

All the gubbins:

By routing the exhaust inside of the box I expect some slight additional heat recovery! Fuel tank vents to felt air filter incorporates a non-return valve, but hoping that the loops in the vent lines will prevent the stuff getting that far - has bee tested in the roll 90 degrees either way about the long dimension. No so visible is the aluminium plate between the heater and the batteries - the idea here is to get some heat to the batteries (after all, it is being used in the cold!) to improve the capacity

With exhaust extension (just visible extending out of the hangar door - I expect to put a hole in the wall at a suitable position in due course) and duct extension (short black length is what will be used to go up the cowl flap for engine heating) for use in the hangar:

Autonomy at minimum heat is in excess of 18 hours which is more than I needed. At maximum I'm expecting more than two hours, which should be more than enough for an engine pre-heat - maybe another report after the cold sets in (it has remained remarkably warm so far this autumn - maybe making a heater is going to give us a mild winter!!)

Edited November 12, 2018 by Awful_Charlie

[Bob_Belville]

On 2/13/2018 at 8:13 AM, bob865 said:

I have considered getting a T fitting to put air into the cabin and into the cowling so I get into a warm plane too.  It's always an option.  Just more hardware to transport though.

I would not do that (again). The setup shown in this old photo resulted in a lot moisture condensing under the carpet. 

[bob865]

17 hours ago, Awful_Charlie said:

Autonomy at minimum heat is in excess of 18 hours which is more than I needed. At maximum I'm expecting more than two hours, which should be more than enough for an engine pre-heat - maybe another report after the cold sets in (it has remained remarkably warm so far this autumn - maybe making a heater is going to give us a mild winter!!)

Nice work!!  I definitely saw room for improvement after I built mine, and you did too.  Maybe I should have patented the idea so I can be like Garmin, if Garmin can sue everyone in aviation, why can't I?

[Keith20EH]

Here is my cheap and easy pre heater, effective, but takes awhile.  Hdw store for about $25. 

[carusoam]

Keith,

Great pic!

for a few dollars more...

add another hose to bring the air back out the other inlet side...

recirculating the warmed air might cut the heating time down...

Increased temperature, with some convection... doesn’t have to perfectly mimic the airflow during flight to be effective.

Engineering ideas, not just a PP today...  

Best regards,

-a-

[Andy95W]

Keith- I have the same set up, but with a smaller diameter hose.  I put it into one cowl flap, block off the front air intakes, and let the warm air rise.  Cool air descends and comes out the other cowl flap.

[One Whiskey Hotel]

Y’all mean like this setup?

This gets things up to about 140 or so after about 2 or 3 hours on a 20 degree night with blankets over the cowling and inlet plugs. Plus I like that oil sump, oil cooler, and cylinders are all heated fairly equally. @carusoam I really like the idea of convection, bringing a hose out the other cowl flap and attaching to the other side of the heater, might cut the heating times down and possibly warmer overall temps. 

I got a bill from some elf for about 50 bucks for this gem. It was made by the same elf who was inspired by a conversation among elves about LED recognition lights recently.

[Awful_Charlie]

OK, as you may have seen, it got quite a bit colder in the last week or two in Europe!

I set the heater up, fuelled with a mixture of heating oil (transpires that on its own this is too viscous at low temperatures for the fuel pump to manage), Avgas (to thin it down) and road diesel (to top it off). As I'd let the batteries go flat, I had to run it with a battery charger attached (hope the batteries recover after a full charge!) The initial draw is horrible (like 7-8 amps) but it settles down to about 2 amps when it's fully fired.

The temperature as shown on various thermometers in the hangar was +1dC, connecting the battery minder to the aircraft and running the JPI monitor gave 28dF for the imperial probes, and -4dC on the metric probes. As the snow was not so crunchy outside, I'm more inclined to think it was nearer +1dC than -5dC - probably about 0dC

Put the two top cowl plugs in, but no cover, and left the intercooler and induction plugs out. Heater took just over two minutes to fire up to hot output, and then put the heater output up the right hand cowl flap and set it to max (nominal 5.5kW of heat)

Took readings from the JPI every 20 minutes or so and plotted the resulting temperatures from the JPI. After half an hour, the right side of the cowl was warm to the touch (to be expected), but the induction and intercooler ducts were warm too, so put in those bungs.

As to be expected, the EGT's rose quickest (greater external surface area to mass ratio), and the right side warmed faster than the left. The oil temperature is as measured by the JPI (ie top of the crankcase just behind the prop) as I didn't have a thermometer that I trusted not to end up in the sump if I dangled it down the dipstick hole! Chart below, left temperature scale in dF, on the right in dC. Final sample is after 75 mins of heat, max output used the whole time, fuel consumption (approx 0.75 litre) suggests it is in the right ballpark. I would guess that if the heat was removed the temperatures would even out through conduction, but that will be another test another day, when I'll also look into possibly better duct positioning/sealing/direction to improve the distribution.

My conclusion: It works, but 5kW is barely enough! Maybe a cowl blanket will help a bit, but I doubt even with that it will be easy to get the whole engine from freezing to +90dF in an hour

[skykrawler]

Definitely like the box heater.

For those that are plugging in I purchased a cheap cell operated switch: 

https://www.amazon.com/OlogyMart-Controlled-Sockets-Controller-Temperature/dp/B07GRFX8XB/ref=sr_1_14?ie=UTF8&qid=1548622811&sr=8-14&keywords=remote+gsm+switch

T-mobile sim, $3.50 per month.

My engine has a heat pad on the pan and bands on the cylinders.  I send a text message 3 hours before I need to start and with a blanket the engine thoroughly warm.   I also have a ceramic type heater that I can leave in the cabin.

I also operate my LED hanger lights through this switch.

[anonymouse]

Hi Guys,

I no longer own a Mooney; but I used to be on this board. Now I own a Cessna TR182. It's a lovely bird, but absolutely refuses to start below about 45 degrees. No amount of jump packs, throttle/mixture combos, flooded starts, dry starts, throttle pumping (no accelerator pump), jumping around in circles or wiggling my ears works. I had a few other people give it a whirl and they also couldn't make it happen. Even an EZ-Heat plug in engine heater for an hour didn't work. 

While searching for solutions outside of the $1000+ Tanis/Reiff preheater or the $1200/mo. heated hangar, I came upon this thread. I took heavy inspiration from the OP in this thread and came up with a battery-free version with longer leads and alligator clamps on my car battery. I didn't want yet another thing to charge and omitting the battery makes the build significantly lighter/easier/cheaper. I ran it for half an hour today with ambient temps about 35 (engine was colder) and a pretty dead battery (from the prior failed attempts) and the plane started as if on a warm day (1 pump of primer, closed throttle, full rich mixture).

Here are some more details and labeled pictures that may give more info to the next person to attempt the build.

Parts:

1x VEVOR 5kw diesel parking heater with the cheapest control option available ($90)

1x 24" plastic toolbox ($25)

1x 1.5 quart coolant overflow bottle ($8)

1x roll of duct tape/heat tape ($5)

1x 12' 4" dryer vent hose ($8)

1x 4" to 3" vent reducer ($5)

1x alligator clamps ($4)

1x 6 foot stranded black wire (the red one is long enough) ($4)

1x small pack of wire nuts (you need only 1) ($3)

4x 1/4" x 3/4" bolts and 4x nuts (for mounting the backing plate) ($1)

Total $153

Notes:

The heater is designed for heating vans/RV's while parked without needing to leave the larger engine running. It is rotated 90 degrees along its long axis for this installation (the most allowed; "up" would have the intake/fuel line/exhaust at the bottom). It produces (clean) hot air out the left side and sucks in clean/cool air from the right side. It uses a separate clean air intake/exhaust from the back side and transmits heat via a heat exchanger within the unit.  My version is designed to be used with the lid open, so I didn't have to cut a hole in the right side.

The heater comes with a metric ton of accessories and hardware, virtually none of which are mentioned in the manual. It comes with a 10 liter gas tank, but that was far too large, so I used a couple bits from that hardware along with a 1.5 qt. coolant overflow bottle from my local auto parts store for the diesel fuel tank. The tank fits perfectly with friction between the tool box and heater case. I left the fuel line intentionally long from the fuel tank to the pump so I can pull it out for refueling outside of the case. The heater case stays cool/warm-ish to the touch, and diesel doesn't ignite without compression at any reasonable temperature, so I'm not too concerned about explosion/detonation. The heater burns about 2 liters/.5 gallons per hour at full power.

The heater kit comes with most of the hardware pictured - the controller, wiring harness, fuel line (cut to size), too large a fuel tank fuel line clamps, filter, fuel pump, screw clamps, and short 3 inch diameter hoses, the rubber mounting gasket and metal backing plate were all in the kit. There is also a bunch of unlabeled mystery hardware that I didn't end up using. What's not in the kit? A negative battery lead longer than a few inches (bizarrely, the positive lead is about 10 feet long), any sort of termination for the wires (they are just stranded insulated copper unceremoniously cut), any semblance of build quality, or a usable instruction manual. It's comically poorly translated, has incredibly blurry images, and features hardware that isn't in the kit while making no mention of hardware that is in the kit. You are really on your own (or, what you can Google).

"Fun" things I discovered while bodging this together:

1. Getting the combustion air in, exhaust air out, fuel line, and four mounting bolts through their holes and through the backing plate is an exercise in patience and frustration. It's very tight tolerance, and the fuel line on my unit was at an angle to the other tubes/bolts.

2. My fresh air intake fan would not spin freely, so I got error E-06 (indicated by the first 6 lights on the control panel blinking). This was resolved by removing the fresh air cap, popping off the plastic cover, stroking my chin thoughtfully, and then taking a screwdriver to the fan and prying it out (toward the right) about 1/4". Then it worked flawlessly. Like I said, build quality is non-existent. Get the German designs ($400-500) if you want better.

3. The 4" dryer vent line at it's near full extension blows 161 degree air at the outlet, which will melt your fuel lines, corrode your engine and make the wings fall off your plane. It fits perfectly in my oil dipstick door, but I could also easily put it in my nose cowling with my cowling plug helping to hold it in. I couldn't figure out an effective spot to put it through the landing gear, but Your Mooney May Vary.

4. Battery usage is near-trivial - about 70 watts to get things started, and then it drops to about 20 watts. I drive an EV, so it's even more trivial for me as the high voltage pack charges the 12V battery, but even barring that, you'd run out of diesel well before you run out of electrons.

5. The exhaust is really noxious as it is getting started/purged, but then it clears up quickly. However, it's still pretty noxious 10-15 minutes after use (probably just the exhaust in the pipe working its way out) as well. I put it in the back of my car and had to keep the windows cracked for a bit. I'm not sure I'd fly with it after use for multiple reasons, but this one being paramount. However, I do store it in the luggage compartment of the plane while parked on the ramp in between uses. Any diesel leaks that manifest would be wholly contained within the toolbox.

6. It stores pretty nicely; immediately after turning the unit off, it's easy to disconnect the leads from the car, toss the wires in the case, close the lid, pick up the box with one hand and the dryer vent line with the other. It doesn't get too warm, even with the lid closed (but again, I use it with the lid open for ample fresh air in).

7. Pressing and holding the "off" button on the control panel turns the fuel pump on for priming/clearing air bubbles out of the fuel line (not in the manual).

8. My control panel has 10 lights for fan control speed/temperature, but you can only adjust the fan from 1 to 6. At least on my model, the last 4 lights are for decoration. Maybe the 8kw version uses those. Maybe it's just a generic controller. Maybe it's just bad build quality.

9. The fuel pump should be mounted at an angle - it cannot be horizontal; ideal is 15-30 degrees, but up to vertical is allowed.

In any case, if I can do it, you can do it. I have next to no motor skills and I don't even own a socket set. A dremel tool or a hole saw kit will make your life immensely easier, but you can do everything I did with a crescent wrench, a Fisher-Price drill, a couple of screwdrivers and a nail clipper (for clipping fuel lines, stripping wires and crimping the connection to the alligator clamps, of course). You really are in the Thunder Dome when it comes to figuring out which of the 4 slightly different sized screws/bolts/nuts that aren't in the manual to use to attach a bit that isn't in the manual to another part that may be in there, but I'm happy to help out if you get lost. For $153, 4-5 hours of head scratching, and about $1 of fuel per pre-heat, it's quite the worthwhile project.

Edited November 28, 2022 by anonymouse

[rbp]

3 hours ago, anonymouse said:

The 4" dryer vent line at it's near full extension blows 161 degree air at the outlet, which will melt your fuel lines, corrode your engine and make the wings fall off your plane. It fits perfectly in my oil dipstick door, but I could also easily put it in my nose cowling with my cowling plug helping to hold it in. I couldn't figure out an effective spot to put it through the landing gear, but Your Mooney May Vary

not quite sure what you're saying -- its too hot?

[anonymouse]

8 hours ago, rbp said:

not quite sure what you're saying -- its too hot?

It's a joke. There's always a lot of hand wringing about damaging your plane by breathing on it the wrong way.

Edited November 28, 2022 by anonymouse