Diesel Heater Duct Routing

[C-Dude]

I am installing an Espar D2 under the galley in my 22' cruiser. I plan to route 1 vent to the vertical surface of the cabinet behind the helm seat. The other vent I would like to run up into the v-berth.

Has anyone routed ventilation into the v-berth and if so how did you run the ducting? Did you have to cut out the fiberglass that holds the gauges and steering wheel in order to make room for the duct to pass? Where did you terminate the vent in the v-berth?

I am thinking of hanging the duct from the v-berth ceiling and running it towards the bow or terminating it right at the beginning of the v-berth next to all the fuses, etc. However, I am not sure which method would be most comfortable and if there may be a better way of skinning the cat. If I mount the vent at the beginning of the v-berth, by the fuses, I am concerned that it will just be blowing right on our heads and ay be less comfortable than if it was blowing towards the front of the v-berth.

Thank you

[colbysmith]

Ben, I installed a Wabasto heater two years ago, and put the main vent in the same place I think you are talking about. (You can link over to Midnight Flyer's photo album and look for the nested album on my heater install.) I have not yet put a separate vent into the V-Berth, but it's been on my mind. The one problem I do worry about, is getting too much heat up there. If I were to run a vent, I think I'd use a much smaller vent line, say 1". I would drill a hole in the seat bulkhead to bring it thru, and then it should be able to just pass thru to the Berth between the hull and the dashboard. For now, I do many nights also run a small fan attached to either the steering wheel or table, directing air into the berth. (Clip on type fan). Another idea I've had is to get like one of those small desk top computer fans, or some other small 12 vt fan that I could mount directly in the berth's aft bulkhead to bring some of the main cabin heated air into the berth. Colby

[C-Dude]

Thanks Colby. I have checked out your install photos previously while researching installation. Great job!!! Interesting how you installed the mounting bracket. I have been thinking of gluing marine starboard onto the hull and screwing the bracket to that, but we will see when I start installation.

I purchased a Y duct fitting in order to split the flow. I agree with your hypothesis on smaller ducting for the v-berth and I have purchased smaller duct for the v-berth run and also the vent on the v-berth ducting will be able to be completely closed, so I think I should be able to control the heat flow.

My only question now is whether or not to terminate the ducting and associated vent at the bulkhead or to run the ducting into the front of v-berth. Terminating at the bulkhead seems like it would be cleaner but getting the heat up to the toes also seems appealing...

BTW, I really like your cover. If you don't mind, where did you get it made, what is it made out of and what was the cost?

Thanks,

Ben

[Marco Flamingo]

Where you place your cold air return is important. On my D2 (and maybe all of them), the thermostat is inside the heater unit. When you set the heat, instead of a "normal" household thermostat based on the air temperature in the living room, for instance, on the D2 you are actually setting based on the temperature of the air returning to the unit. My original idea was to use all outside air and have the D2 bring in fresh, dry air. It wouldn't be as efficient, but on a 16, efficiency isn't an issue. What I found out was that, even with the heat control in the warm cabin, the unit would never sense that the boat had warmed up and it would cook me.

I also found somewhere online a diagram showing the maximum length of run allowed for the intake and heat ducts. Elbows, smaller duct work, and Ys shorten that considerably. The instances where people had any trouble with the D2 always seemed to be cases where they had installed complex duct work.

I can't help with actual routing, as I'm not familiar with your install. Also, I basically use mine to warm up in the morning and warm the bed at night. Other than that, I only use it if I'm soaking wet.

Mark

[thataway]

Ben, you noted:

[C-Dude]

Marco, 10-4, the install manual comes with an allowable formula to use for maximum duct runs and fittings. I am using the formula in my run calculations and I will ensure the install is within allowable parameters per Espar.

I will be cognizant of the cold air return as well, good point. I would've thought the thermostat was on the adjustable temperature control that is mounted in the cabin. Luckily, i can lengthen the intake later if I experience issues with cabin overheating.

Bob, great point. Thank you. Much better to learn that lesson the easy way.

Thanks,

Ben

[colbysmith]

Ben, I would agree with terminating the vent up by the bow. Except, I like your idea of having a "register" on the vent to close it off, which would then make more sense to have it within reach. Maybe midway up into the berth would make more sense. My cover was custom made by a local guy that does excellent work. (Albeit, he usually takes longer than he initially promises, but the quality makes up for that. lol) I believe I have about $1500 or a little more wrapped up in that cover, due to several modifications. (new larger radar antenna, then a new larger anchor roller....) I forget the name of the material, but it's basically the same stuff that semi's use or perhaps a version of sunbrella. He also made my curtains, and has done past cover work for me. I can also tow the boat with it covered, however many times do not as it's not as fuel efficient towing it with the added wind resistance. Colby

[C-Dude]

According to the literature on he Espar digital max controller , it has an ambient temperature sensor

"Products Description

The Digi-Max controller provides an easy to set digital display, an onboard ambient air temperature sensor, an adjustable auto shutoff, adjustable low voltage protection, records maintenance hours, and displays troubleshooting tips for fault codes displayed."

So, hopefully the thermostat will be on the "ambient air temperature sensor" that will be measured by the cabin temperature not at the heater itself......

We shall see

[C-Dude]

According to the literature on he Espar digital max controller , it has an ambient temperature sensor

"Products Description

The Digi-Max controller provides an easy to set digital display, an onboard ambient air temperature sensor, an adjustable auto shutoff, adjustable low voltage protection, records maintenance hours, and displays troubleshooting tips for fault codes displayed."

So, hopefully the thermostat will be on the "ambient air temperature sensor" that will be measured by the cabin temperature not at the heater itself......

We shall see

[brooks&judy]

Our boat has a Wabasto diesel furnace ducted to two outlets, one just inside the bilge pump sump through the panel just below the under-counter galley doors; the other duct runs forward through the panel under the helm seat into the under-foot locker near the side of the boat, then down against the partial bulkhead to exit at the cabin sole.

Both ducts lead to outlets that can be closed or turned to send the hot air in any direction. The aft outlet can be aimed up & out toward the cockpit which helps there when the camper-back has it closed in - or it can aim across to the person sitting aft at the settee.

The forward duct can be aimed forward and the natural rise of hot air warms the f'o'cle bunk, partly from under the bunk which is fine.

Air moves through anchored or docked boats typically from aft forward. Air also generally circulates into a space through the largest opening and out the smallest. Even with the door closed, if the windows are too, air will enter the cabin through the wire & control chase under the starboard side deck and exit slowly through the hause hole on the foredeck, again making the air move naturally from main cabin over the V-berth.

With our system, we're warm wherever we are in the boat. We turn the furnace off just before climbing into bed and the first one up turns it on if it's below about 55. We find our Wabasto heats the cabin rapidly - and then the cabin cools fairly slowly if the curtains are closed. It will tend to cycle on & off.

I doubt you need to do as much ducting into the f'o'cle as you propose to stay comfortable. You mentioned putting an outlet right behind the driver's seat, if I read it correctly. Remember, heat rises. Owners of Wallace stoves say when they are used as cabin heater, occupants are warm from the waist up, whereas ducting down to cabin sole level keeps you warm from feet up.

A benefit to any good cabin heater is drying the boat out in damp Northwest mornings, the interior made more moist by our overnight breathing: We heat the cabin a bit beyond what's comfortable as we dress - and then put on jackets and open the fore-hatch and door and let the warmed & rising moist air flow out the forward hatch. We then open the center windshield a minute before we close the boat up and enjoy a relatively dry home afloat with windows no longer fogged.

Best wishes!

[C-Dude]

excellent advice, thank you. Mounting the vents low sounds like a great idea.