Cabin Heaters

[GordMay]

PROPANE CABIN HEATERS:

I recommend the use of Direct Vent heaters c/w co-axial flues (chimney or vent).

Direct-vent space heaters use sealed combustion so the combustion process is totally separate from the room air - they don't consume indoor air, and they don't affect indoor air quality.

Using a coaxial vent system, (a pipe within a pipe), outside combustion air is drawn in through the outer pipe into a sealed combustion chamber containing the burner system. Exhaust flue gases are then vented through the inner pipe outside of the boat. Generally speaking, a co-axial flue is about twice the diameter of a B-Vent (Natural Venting).

Naturally vented appliances use interior cabin air for combustion, and often a single wall flue (a double wall ‘B-Vent’ would be preferable).

Most manufacturers provide thermocouple protection (no flame = no gas), and (usually with naturally vented equipment) oxygen-depletion protection (low oxygen = no gas) devices, both useful safety features.

I would recommend the installation of a good gas detector/alarm (CO & CO2, and if using a Diesel appliance NO2).

Manufacturers:

Force 10 Marine www.force10.com
Offers it’s model “1300" heater c/w 12VDC Circulating Fan (variable 4,000 - 9,000 BTU/Hr), utilizing a S/S co-axial flue.

Dickinson Marine www.dickinsonmarine.com
Offers it’s “P9000 -&- P12000” model heaters c/w 12VDC Circulating Fan (Max. 9000- BTU/H & 12000 BTU/H) , utilizing a S/S co-axial flue.

OTHERS ???

Regards,

[delmarrey]

It doesn't suck that cold air in thru the gaps in the gangway hatch.

[cpa]

i love my dickenson p9000, will never do back to diesel/kerosene

[tenknots]

While it's true that a CO detector is important for any combustion heater mounted inside, it should be known that diesel and kerosene produce about a tenth of the CO as is produced by propane or alcohol.

It's great to have pipes within pipes, but if you have an older heater without that luxury, make sure there is a way for combustion air to get inside. And mount a CO detector with a digital reading so you can monitor problems before the alarm goes off. If you're depending on your detector to save your life, get more than one and replace them every three or four years.

[GordMay]

Tenknots writes:
"While it's true that a CO detector is important for any combustion heater mounted inside, it should be known that diesel and kerosene produce about a tenth of the CO as is produced by propane or alcohol...."

Please be aware that Diesel produces NO2 (Nitrogen Dioxide) and several THOUSAND other pollutants.

The air contamination potential for both un-vented gas and kerosene space heaters is CO, CO2, NO, NO2, RSPs, SO2, and formaldehydes.

Be AWARE!

[delmarrey]

(Compressed Natural Gas) would be ideal for heating but the availability is still a little scarce especially at a marina. But maybe in 20 - 30 years we'll be setting up stations for the public most everywhere. The big problem for now is COST of compression. LNG (Liquidified Natural Gas) is easier to convert to CNG but is less efficient without the small percentages of Propane, Ethane, Butane and other gases. Also, it has to be delivered in trucks rather than out of a main pipe.

In the boat, it would be nice to have a CNG engine as well, the only problem would be the tank storage. It has to be on the exterior just like propane, but you could run the whole boat on one tank.

CNG also has the highest safety record to date. No one has died, yet, due to the use of CNG.

We have over 100 cars and trucks in our facility, and the only real problems are the people that don't listen and/or abide to procedures.

Just a thought!

[tenknots]

GordMay, you're right, I didn't mean to imply that diesel or kero heaters aren't dangerous, but no one that I know has died of NO2 and NO2 detectors are hard to come by, so it doesn't appear to be an issue. Every year plenty of people die of CO poisoning and CO detctors are available - every boat that burns fuel should have one.

The build up of the chemicals you mention are certainly not good for humans, but I feel that diesel and kero heaters are safer than other types if there is a problem since the risk of CO poisoning is lessened.

[GordMay]

Tenknots:
I'll have to defer to your apparent expertise, and support your advice to install a readily available CO detector - with one further caution:

All of the specifications for products of combustion assume 100% combustion.
Dirty orifices & etc., that can cause incomplete combustion, WILL have deleterious effects.

'Cause I just can't seem to "let go"

[Jim Cate]

Question: Why is a vented propane space heater so dangerous, but a completely unvented propane cooking stove (which most uf us use daily) considered safe (with reference to combustion products,not explosive mixtures in the bilge)?

[Sandero]

I have a diesel fired Espar Airtronic 4 which cost in kit form about $1500 for 3 outlets. It's invisible, and provides forced warm air and uses outside air for combustion. It's saqfe, thermostatically controlled and uses little electricity after start up.
I love it.