Vented Cat Heater in a Van?

[Cammalu]

Should be roughly 300 cubic feet of air space in something the size of a Chevy Express. The human body produces about 340btu. That leaves 5,000btu to raise the temp one degree F per minute. In other words, if your van interior matched the ambient temp of 0F then it would take 1 hour to raise the temp all the way to 60F with the heater on the whole time. Once 60F is achieved it will only take a small fraction of that runtime to maintain that temperature.

Or you can just put one menopausal/post menopausal woman in the van and with the heat generated you will never have to worry about heating your van again. It's at least 2000 degrees boiling inside off and on.

 

[masterplumber]

I thought I'd chime in on the Mr Buddy band wagon. I have a cargo trailer with roughly the same dimensions as a high top extended cargo van. I have 1" foam in the walls, 1" foam and 1 layer reflectex in the ceiling, and just a felt pad and indoor/outdoor carpet on the floor. In the winter in Colorado at 0 F and the starting temp inside roughly the same, I can turn my Mr Buddy on high and be 70 F inside in about 45 min. Then I can turn it to low and maintain that temp, sometimes even turning it to pilot. I had plans for a Dickenson sailboat furnace originally, but already had the Mr Buddy from my previous camper. Saved over a $1000. This is all at 7500 ft elevation which reduces efficiency of any combustion appliance.

 

[Raven+Squid]

The temperature gradation between the floor and ceiling is tends to be rather significant. The closer your bed is to the ceiling the less heat you'll need a night. And night tends to be when you need the most heat.

Unless you add sleeping bags and a wool cap into the mix. Then your need for heat(at least at night and moderately cold temps) goes way down.

 

[Gideon33w]

You actually mean Thermal Stratification.

Thermal stratification should only be about 1 degree C per meter. If you are having issues beyond that mark then you have an insulation problem. Most likely allowing induction of the naturally cooler ground temps through the floor.

For $10 you can throw down some carpet and see if the stratification is reduced. Even the minor R value of carpet would help. If you see a marked improvement you know that your issue is the floor conducting cooler temps to the living space.

 

[Raven+Squid]

You actually mean Thermal Stratification.

Thermal stratification should only be about 1 degree C per meter. If you are having issues beyond that mark then you have an insulation problem. Most likely allowing induction of the naturally cooler ground temps through the floor.

For $10 you can throw down some carpet and see if the stratification is reduced. Even the minor R value of carpet would help. If you see a marked improvement you know that your issue is the floor conducting cooler temps to the living space.

Thermal stratification it is!

Yea it's definitely a poor insulation/air infiltration thing. That stratification is about 1degree F/per inch for us haha! we have 1layer of reflectix, then layer of 1/4ply, then vinyl flooring then yoga mats then a throw rug. Haha!

 

[Gideon33w]

Nearly everyone on here installs reflectix wrong so that is no surprise. The yoga mat material makes for reasonable sound dampening and cushion but has poor R value. 

To keep the floor reasonably thin but gain a huge improvement I'd suggest foamboard down 1st (you might want to add struts), followed by a layer of mylar (space blanket material or reflectix), plywood, and then carpet.

A radient barrier material (ie mylar or reflectix) placed directly against metal will do  absolutely nothing. With reflectix you are actually only gaining the radiant effects from one side of the material because the other side contacts the vehicle skin.

To be more on topic ... The better you insulate the less energy you must expend to heat/cool. Considering how expensive it is to have high btu output heating/cooling and then power that appliance it is FAR more cost effective to insulate properly.

 

[ascii_man]

Have you insulated your van?

Generally speaking, I am a real world test kind of a guy.  I would take a double burner camp stove, most of them are about 10k BTU per burner that I've had.  Crack each front window 2 inches, fire up both burners full blast, and see how long it takes to heat things up to where you want them.

By doing this you will have a base figure to start with, that with simple math you can CORRECTLY figure out your needs.

The reason that I asked these questions is that I don't own a van yet, so I can't test. But I needed to order my heater ASAP due the 8-week lead time and cold weather.

But I've ordered a 5200 BTU/h unit and will see how it does.

 

[Gideon33w]

Without the ability to test makes the case for listening to practical experience all the more compelling ...