What size Reflek heater do I need?

[Onemoreproject]

Hello,
I am refitting a 36' cold molded (wooden) boat and want to install a Refleks heater.
My boat has a 15LX10WX6H= 744 cubic feet in the main cabin that with a 2 quarter berths with only curtains separating them from the main cabin. They add an additional 7x8x4= 174 cubic feet of volume. I have low expectations about how much heat will make its way forward into the head and vee berth. Although if we are sleeping in the vee berth, I will direct some heat that way with fans.

The heater that has been recommended to me is an MK66 that puts out 5500 BTUs. They burn cleanest on high. I am concerned that a larger heater will be uncomfortably hot at the lowest setting and that when they are turned down, they don't burn as cleanly - making soot and needing to be cleaned more often.

If anyone has experience with a Refleks of any size I would like to hear about it.

Thank-you,
Onemoreproject

[NornaBiron]

We have a Refleks 60/61M installed in our saloon which heats the whole boat via radiators. It also supplies hot water via a coil through the heater and another through the hot water tank. We generally run it on low, the heat produced is comfortable throughout the whole boat and the water gets very hot within 2 hours (we have a 60 litre tank). Running on low uses approximately 40mls of deisel per hour, it burns much hotter on kerosene but we can't always get it. We live aboard on the anchor full time so run the heater all winter and it only gets cleaned once per year. We have a separate air intake chimney for the heater so that we are not reliant on cabin airflow. My husband worked on trawlers that all had the same model of Refleks heater but without the second (intake) chimney, the only problems ever encountered were when the cabin airflow was restricted. The heater does get red hot if run on full - far too hot for the cabin.

[Littlechay]

I have sailed extensively on several boats with Refleks heaters and am a big fan. My boat is of similar dimensions to yours and the 66MK should be fine. It is what i have but what is your insulation like?

In my experience people who buy the next size up end up downsizing as they have to run their heater on low and are always cleaning it.

As for fans, get one of the ecofan range of heat powered stove top fans. I had one on Pelagic and it worked even at sea held in place with a couple of bungees. The fan is important as it gets rid of the hot spot around the Refleks and circulates enough air to even help keep your feet warm.

Chris

[Sailormantx]

60 Mk size works well on my 42' schooner. You will learn through experience just how low a setting it can be run at without getting carboned up. Flue length is important for a good draft. Even with a 1.5 meter stack, it can be tough to light in high winds. Usually opening a windward facing port pressurizes the cabins enough to get it going and once it is hot all is good. A fan blowing down across the heater is essential otherwise all the heat stays by the heater and you will have cold feet


Thanks for the tip on ecofans, that is something I can use.