Insulating cold floor in mobile home.

[^woody^]

I've spent many winters in a Portakabin office and nothing makes the damn floor any warmer. Electric heated mats under feet at the desk, carpets, heating whatever, it does not work. You are going to need something like 250mm of insulation to stop that floor feeling cold.

 

[Harry Bloomfield]

I've spent many winters in a Portakabin office and nothing makes the damn floor any warmer. Electric heated mats under feet at the desk, carpets, heating whatever, it does not work. You are going to need something like 250mm of insulation to stop that floor feeling cold.

I wonder if boarding around the edge would make much difference, to help reduce the cooling air flow below the OP's floor?

 

[Old Salt]

I wonder if boarding around the edge would make much difference, to help reduce the cooling air flow below the OP's floor?

I was thinking that, I have a skirt for my motorhome that is supposed to stop the wind whistling underneath.

You will need to add some “air bricks” or something to enable some airflow to prevent damp, mould etc.

 

[^woody^]

I wonder if boarding around the edge would make much difference, to help reduce the cooling air flow below the OP's floor?

I don't know. The retained air may well be a very slight bit warmer but I doubt enough to make a difference.

 

[Ufoxed]

Hi guys thanks for your time and replies.....The walls are all newly insulated ,double glazed windows ,the roof is ok no major leaks as I can tell as the roof is always covered when we have a frost...good sign. I three oiled filled 250kw radiators one in each room so plenty of heat. Woody- there is no more room underneath to get anymore insulation in,130mm that I have is more than Xtratherm advised me to: they said that 90mm would be sufficient!!
I was thinking along the same lines as Harry Bloomfield will lay visqueen underneath on the floor as it is always damp under there (bit of a slope) the mobile has a skirt made of decking but has gaps between so will use bubble wrap with foil both sides as a lining on the inside and No vent ...Its all I can think of at the moment . the trouble is your feet are cold your body is warm from heating so you start sweating it is so uncomfortable,then there is the sleeping bit as the bed is two foot off the ground so you cant get warm there even with an electric blanket.....So slippers no good

 

[just pumps]

edit.

 

[IT Minion]

The air in your caravan is the only way that floor is going to be heated. It will, slowly, shed that heat through the insulation so it will always be a bit colder than that air.

The air at the bottom of a room is always the coldest, as hot air rises and cold air sinks. I'd be surprised if you didn't find the air quite cold if you laid down on the floor.

You could go for underfloor heating, but even with that you might not have warm floors all the time as it won't need to be on full time. Now you've got a lovely insulated floor that heat will nearly all rise up and warm your home.

Finally the feeling of cold isn't about absolute temperature, it's about transfer of heat. Metal feels colder than plastic at the same temperature.

 

[big-all]

i assume you mean 250w x3 is only 750 w i suspect you need nearer or maybe above 2500-3000w to overcome heat loss dependent on comfort required
you dont say iff you expect to be bare foot or dressed for outside, so possibly a draft from somewhere drawing the heat out at floor level
the temperature at floor can easilly be 6 degrees less than shoulder height, even more with a draught ??

 

[Harry Bloomfield]

A major problem which I soon spotted in the design of my tourers blown air heating system, was the part where it blew 'warm' to air to the bathroom at the rear. There were three outlets, two feeding air to the front area, one to that rear bathroom. The heat source located in the middle, blowing along ducts along the inside cupboards to the front left, with air drawn back in to the heater, to recirculate. As the door was on the left, to the rear of the heater, the only route was to take the duct under the floor emerging on the right in the bathroom. Just bare, uninsulated, flexible, metallised air ducting. By the time the warm air had emerged at the far end of this duct, when the weather was cold, it was simply blowing cold air. Not just blowing cold air, but cooling the entire caravan down too and simply negating the heat produced by two other ducts.

An incredibly stupid design and the designer had obviously never tested the system in cold weather. I solved it by removing the underfloor duct completely and installing a new outlet blowing towards the rear area from forward of the door and into the bathroom.