Go big or go home:

[charlieaarons]

750w is not a “tiny heater”.
In my comparably sized camper with 55mm (2.2”) urethane insulation it takes ~30w to maintain 1C temperature gradient. 750w is worth 25C (45F). Plus 2 human bodies = 100w each = 7C or 12F. In other words if it’s 30F outside it would be 87F inside.

 

[MTVR]

750w is not a “tiny heater”.
In my comparably sized camper with 55mm (2.2”) urethane insulation it takes ~30w to maintain 1C temperature gradient. 750w is worth 25C (45F). Plus 2 human bodies = 100w each = 7C or 12F. In other words if it’s 30F outside it would be 87F inside.

We kept turning the thermostat down and down and down, and eventually had to turn it off.

I think that if the dog had spent the whole night with us, we would not have needed any additional heat.

And once we get the gaps foamed, it's gonna work even better...

 

[1000arms]

Yesterday we finished insulating the walls and did the ceiling. The weather forecast said it was going to be down around freezing last night, so we decided to spend the night in it to see how well the insulation works.

It actually dipped below freezing last night, and even though we haven't foamed the gaps, our own body heat alone was almost enough to keep us warm. We had a tiny little 750-watt heater in there, but we kept having to turn it down and turn it off to keep us from sweating...

750w is not a “tiny heater”.
In my comparably sized camper with 55mm (2.2”) urethane insulation it takes ~30w to maintain 1C temperature gradient. 750w is worth 25C (45F). Plus 2 human bodies = 100w each = 7C or 12F. In other words if it’s 30F outside it would be 87F inside.

We kept turning the thermostat down and down and down, and eventually had to turn it off.

I think that if the dog had spent the whole night with us, we would not have needed any additional heat.

And once we get the gaps foamed, it's gonna work even better...

I thought tiny heaters were used to heat tiny homes, even tiny homes with drawbridges? ...

I think @MTVR was referring to the physical size of the heater.

 

[MTVR]

Yes- the heater was small...

 

[charlieaarons]

I have 2 x 700w reliable failsafe 120v aircraft heaters. One has a 40F thermostat, the other 70F but an adjustable thermostat in series at 41F off, 37.4F on.
The 55mm urethane radiates at 0.44W/sq meter per deg K. Taking into account the permittivity of the 2.3 sq meters of windows at ~ 1.75-2.0 w/sq m per deg K, and rounding everything up, it adds up to about 26w per deg K, so I rounded up to 30w/deg K. As stated the 2 thermostats are at 3-5C. So the two heaters can keep the water system from freezing down to -40. With just 1400w = 12A. That’s about US 9.3 cents/day for every deg F below 41F. Comes out to ~$2-300/winter, but I hate broken hoses.
About 5x5x4” in size. Not cheap, but made in USA and “you get what you pay for”.

 

[MTVR]

Just don't confuse the PL Premium and the Pumpkin Pack!

I do enjoy high-quality pumpkin beers in the fall...

 

[MTVR]

Spent the night in it last night again. It was below freezing again, and we used no heat. It was still fine...

 

[MTVR]

...

 

[MTVR]

Foamed the drawbridge insulation today:

 

[shortbus4x4]

Looks like your beer exploded in there and is coming out the cracks.

 

[MTVR]

Just making damned sure that there is zero airspace inside the walls...

 

[1000arms]

Yesterday we finished insulating the walls and did the ceiling. The weather forecast said it was going to be down around freezing last night, so we decided to spend the night in it to see how well the insulation works.

It actually dipped below freezing last night, and even though we haven't foamed the gaps, our own body heat alone was almost enough to keep us warm. We had a tiny little 750-watt heater in there, but we kept having to turn it down and turn it off to keep us from sweating...

View attachment 621069

Just don't confuse the PL Premium and the Pumpkin Pack!

I do enjoy high-quality pumpkin beers in the fall...

Foamed the drawbridge insulation today:

View attachment 621467View attachment 621467

Looks like your beer exploded in there and is coming out the cracks.

Just making damned sure that there is zero airspace inside the walls...

Well, you did say that you had foamed the drawbridge, but you didn't mention what you had used!

 

[MTVR]

We screwed and glued the exterior sheathing onto the drawbridge the other day...

 

[MTVR]

...then we trimmed, filled, and sanded it...

 

[MTVR]

...and yesterday we applied three coats of marine-grade epoxy to it, inside and out...