Planar Heater Install

[ak-guy]

I have a Planar 44d heater on the way that I will be installing it in my Allweather. When I got the boat it had a very old non functional Webasto that I removed. The Allweather is only 26' and basically one space inside. Wheelhouse - setees - V berth not even an enclosed head. The heater will be installed close to where the old Webasto was using the same exhaust thru hull and in the wheelhouse area. The former heater was simply installed with combustion air and heater air both being drawn from inside the boat. Reading online about these type of heaters I find a lot of conflicting information concerning intake air for combustion and heating. I know that official instructions say that combustion air must not be taken from accommodation space but perhaps they are mostly concerned with tight truck cabs. The Allweather has plenty of designed-in ventilation so I am not too worried about the heater combustion air intake, should I be? I mostly want to have the interior air drying effects these heaters are known for. Should I draw combustion air from outside? How about heater air?

 

[Gdavid]

If the combustion air is drawn from the cabin, you will have cold air drawn into the cabin to make up for the lost volume which makes the heater less effective and creates uncomfortable drafts. Most boats have a lot of infiltration already but pulling a vacuum on the space will make the drafts much worse.

 

[CaptTom]

On my Planar I draw combustion air from the space where the heater is, which is connected to the engine room, which is well ventilated. Cabin air in and heated air out have their own ducts. Personally, I doubt you'll have anything to worry about just using the same set-up as before.

I don't know about the Webasto, but I can tell you that the exhaust pipe for the Planar gets dangerously hot. Make sure it's far away from anything combustible and well insulated.

 

[Nomad Willy]

My Wabasto draws combustion air from a belowdecks compartment just aft of the engine compartment. I call it "the hold". The 10' exhaust exits outside the transom. Been that way for about eight years.

 

[garrobito]

I'm in the process to finish installing a planar. I bump in a couple troubles, including the fact you need to run first time around 30 minutes in order to burn the chamber. i found diesel pump was unreliable and ended replacing.
Not totally convinced of this product. I would get a webasto or espar next time...

 

[Pau Hana]

If the combustion air is drawn from the cabin, you will have cold air drawn into the cabin to make up for the lost volume which makes the heater less effective and creates uncomfortable drafts. Most boats have a lot of infiltration already but pulling a vacuum on the space will make the drafts much worse.

Yup yup yup!

Combustion air must be taken from outside the vessel.

 

[CaptTom]

I would get a webasto or espar next time.../QUOTE]

So would I, IF it weren't for the fact that I could buy three Planars for the same price. Or buy two, have a full set of spares and still save money.

I've heard others mention fuel pump failure, that might be a good spare to stock.

I did have to run it for a while to burn off the oils from the exhaust hose manufacturing process. I expected it, the manual mentioned it, but it was still scary to see and smell smoke. It's all gone now, but it made me very cautious about running it.

 

[Nomad Willy]

Yup yup yup!

Combustion air must be taken from outside the vessel.

Says who?
I didn't install mine. The boat was in LaConner and we were in Alaska. The Wabasto install was part of the engine repower.
Your word "must" obviously isn't true as in a previous post you'll see we have been using the Webasto for years drawing both combustion air and inlet heater air from inside the boat. But it may be advisable to have outside air for combustion. In theory it would seem to work better and in the install instructions it may even say to plumb it from outside. But I can confirm that it does work fine drawing from inside the boat.
I was concerned about my exhaust length as it was at the maximum recomended length of 10'. Perhaps that's why I left the intake plumbing length at 1". To make the exhaust plumbing expel air at a good safe rate .. not too hot. Without much trouble I could install exhaust intake plumbing for an outside intake. If it would increase my efficiency 25% I'd be doing it but I'll bet it would be more like > 5%. I'll be going to Sure Marine in a few days and I'll ask about this.

 

[ak-guy]

I almost installed a Dickinson Newport diesel heater but could not find a good place to put it. The Newport would take combustion air from inside the cabin of course and the instructions do say to provide said air. I don't see the difference though if the boat interior has a good supply of fresh air from somewhere it would make no difference if you had a Newport or a Planar drawing inside air for combustion. I want to minimize interior humidity so encouraging air movement is important. Drawing combustion air from inside and or heating air from outside would seem to be the answer.

 

[Pau Hana]

Says who?
I didn't install mine. The boat was in LaConner and we were in Alaska. The Wabasto install was part of the engine repower.
Your word "must" obviously isn't true as in a previous post you'll see we have been using the Webasto for years drawing both combustion air and inlet heater air from inside the boat. But it may be advisable to have outside air for combustion. In theory it would seem to work better and in the install instructions it may even say to plumb it from outside. But I can confirm that it does work fine drawing from inside the boat.
I was concerned about my exhaust length as it was at the maximum recomended length of 10'. Perhaps that's why I left the intake plumbing length at 1". To make the exhaust plumbing expel air at a good safe rate .. not too hot. Without much trouble I could install exhaust intake plumbing for an outside intake. If it would increase my efficiency 25% I'd be doing it but I'll bet it would be more like > 5%. I'll be going to Sure Marine in a few days and I'll ask about this.

Just checked the Wallas folks- I was wrong. Wallas 40DT takes combustion air from the engine room/install location, and strongly suggests that the intake for the inlet (heated) air be taken from both inside and outside the vessel. Reasoning is that the make-up air from outside the vessel keeps the vessel interior supplied with fresh air vice recirculating the interior air.

 

[Nomad Willy]

Thanks Peter,
I was down there yesterday and could'nt remember what I was going to ask Sure Marine about at the moment I was ready to leave. They told me to call .. haha but you beat me to it.
Mine Wabasto is ready to reinstall now. But an additional air intake won't be needed. May work on my radio first though.

Re the choice Wabasto/Espar or Wallas I think it had more to do w fuel burn than quietness. But I still really don't remember why I bought the Wabasto. The Wabasto is plenty quiet to suit me but for some the extra quiet is important.

 

[spinoeca]

I talked to Sergei at Planar BC today and asked this same question. His response was that it is an issue of oxygen concentration. If you use inside cabin air for the combustion supply you diminish the concentration of oxygen and in a totally tight system that wouldn't be sustainable. I suspect none of us have completely tight systems but short of monitoring O2 concentrations I don't plan on using cabin air for combustion. Easy enough to run a short length of intake into the engine compartment right below my installation.

 

[Nomad Willy]

spinoeca,
My 1" combustion air intake is located in a compartment just aft of and level w the engine compartment. Fresh air comes into this space directly through a 2' X 3' hole in the bulkhead tween the Laz and the storage compartment aft of the engine compartment. There are numerous slotted holes in the inside of the aft cockpit enclosure. So plenty of fresh air is available. I can't imagine how it would be much different vented directly outside.

I see your plan to use the engine compartment for combustion air. If the only access to outside air is through the engine intake vents probably on the side of the boat the engine and the heater could be competing for air unless the size of the vents was large and the engine small.

 

[CaptTom]

I talked to Sergei at Planar BC today and asked this same question. His response was that it is an issue of oxygen concentration. If you use inside cabin air for the combustion supply you diminish the concentration of oxygen and in a totally tight system that wouldn't be sustainable.

I'm not sure I understand. If you use cabin air for combustion, and send the exhaust outside the hull, one of two things is going to happen:

1: In this theoretical air-tight cabin, you'd bring down the pressure until the heater's fan could no longer pull enough combustion air, and it would stop.

2: In the real world, air would find its way in to replace the air that's vented outside.

Neither of these scenarios changes the concentration of O2 in the cabin air.

I suppose if you discharged the exhaust into the cabin, that could happen. But I haven't heard anyone recommend that!

I'd be comfortable using air from the cabin, or better yet, the ER, for combustion.

 

[koliver]

Chances are good that if you are drawing combustion air from the ER, that air is being replaced through a variety of sources.
1 obvious ER vents on the cabin sides
2 not so obvious gaps in the flooring of the cabin, such as, where the holes are cut for controls to the helm, heat pipes to the fwd cabin, aft cabin and main cabin,
3 uncompleted flooring in the forepeak locker,
4 drainage channel from the chain locker.
5 where the bilge limber holes allow air from the lazarette to pass through to the ER, vents from the laz through the transom.

After you have located all of the openings, added up the cross sectional area of those, you will very likely find an excess for all your needs.

 

[spinoeca]

My thoughts exactly. I know that my Ideal windlass as it is currently set up vents directly to the chain locker thence to the bilge. Capt. Tom's assertion that the O2 concentration inside the cabin wouldn't change is correct. The gas minus the burned O2 is the exhaust which is vented outside. So I feel comfortable not going into the ER for the source air to feed the combustion.