Friday, 22 October 2010

Planning for the cold

We know that we are going to be seriously affected by the cold weather. For the last twenty years we have been living in Australia where we have experienced a warm and dry climate. The locals have no idea of cold weather. In winter they dress in anoraks, beanies, scarves and gloves. In comparison, I will be wearing a T shirt and shorts. They talk about the frost on the ground which in reality is dew! However we are old enough to remember years of living on New Zealand’s North Island volcanic plateau where we had snow drifts and biting winds. Insulating the boat is a priority. Most new boats are spray foam insulated on their sides and ceiling. We will have the same. However I also want insulation under the floor. The problem was finding room for the insulation. Any insulation must have a gap between it and the underside of the timber flooring. There must also be a gap between the ballast and the floor to scour the bilge. Unfortunately there didn’t appear to be sufficient clearance to achieve this. We could reduce the headroom in the boat, however I hit upon another idea. By increasing the thickness of the baseplate and its weight I could reduce the amount of ballast. After doing some calculations I specified the baseplate thickness at 20mm which is double the conventional thickness. The increased weight of the baseplate halved the amount of ballast and provided sufficient clearance to fit 1” Kingspan foil backed foam sheeting between the ballast and the flooring. I also read a magazine article where foil backed bubble wrap was inserted between the spray foam insulation and the wall and ceiling panelling to provide double insulation on the walls and ceiling. So I’ve included this in the boat specifications.
It’s not sufficient to rely solely on insulation to keep the boat warm. We need active forms of heating. The boat will have a Lockgate diesel stove in the saloon. The location of the saloon means the stove will be reasonably central and we hope this will assist in keeping the boat warm while we are awake and not cruising. The central heating system will be a combination of finrads at floor level and smaller heater panels in the wardrobes. When cruising the heater source will be the engine, otherwise it will come from a Hurricane heater. The Hurricane is designed and manufactured in Canada. It is more expensive than other available options, however my previous experience with Canadian cold weather equipment has been very positive and we are hopeful the Hurricane will prove to be a good choice.
We will know if the heating and insulation plan has been a success if the boat is warm in winter whilst the exterior is coated in snow.

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