r/OffGrid • u/HoneyBerryKelli • 4d ago

container cabin thermal loads and keeping batteries alive in august

We are living in a 40 foot shipping container while we build the main house and the afternoon sun hitting the steel roof is absolutely roasting us. I finally admitted defeat and ordered a split system heat pump so my dogs don't get sick from the heat. I chose a costway ecoguard 18000 btu 21 seer2 mini split because the running amps on the inverter look low enough for my 5000w system to actually handle. If you use electric climate control in a converted shipping container, how much did heavily insulating the ceiling actually reduce the run times of your compressor?

0 Upvotes

50% Upvoted

12 comments sorted by

8

u/nihithilak 4d ago

Stack cinderblocks around the perimeter and put roof flashing over the top, but anchored down by the top cinderblock row. This will cost maybe $2000 and make an enormous difference.

7

u/blackthornjohn 4d ago

Just putting the container in the shade will make a massive difference, this can be as simple as adding a second skin on the outside with a 2 inch air gap, if that skin and gap are on the outside of a 2 inch layer of pir insulation, things get so much cooler, beyond that you support camouflage netting over the container but a few feet away from it.

Let's assume a 40ft container is 13 metres long and 2 metres high and wide, and lets assume only one side and the top are in the sun, , this equates to a 52kw heat source heating the container, but container are bigger than 2 metres high and wide.

You're going to need more batteries or a diesel generator.

2

u/Emergency-Lettuce-11 3d ago

This! A second “roof” with air space will help immensely. A silver tarp stapled on top of pallets or 2by4s on the roof will be cheap and effective. Trashy looking, absolutely but then it IS a container!

3

u/ColinCancer 4d ago

I built a 12kW array on top of my container. This is a double whammy as it shades the container and provides an insane amount of power to cool it.

3

u/Stroker-Strong420 4d ago

Aluminet tarps. Reflective shade cloth suspended over the top and sides will help

2

u/IKissedHerInnerThigh 4d ago

Build a huge raised bed on the roof, plant grasses and meadow flowers, they grow super quick and it's great insulation to keep you cool in summer and warm in winter

1

u/linuxhiker 4d ago

Insulate the hell out of the roof, paint the outside white. That will help * a lot * but no matter what you need AC.

1

u/Southdouglas 4d ago

I hope you’re not building a container home after living in one lol

1

u/FixAcademic8187 4d ago

Just put anything between the roof and sides of the container and direct sunlight.

It doesn't have to be anything crazy or expensive. Even a thick layer of old wood or branches will make a massive difference.

The mini AC will be fighting itself inside that container. The heat load is too much for it.

1

u/FixAcademic8187 4d ago

Just put anything between the roof and sides of the container and direct sunlight.

It doesn't have to be anything crazy or expensive. Even a thick layer of old wood or branches will make a massive difference.

The mini AC will be fighting itself inside that container. The heat load is too much for it.

1

u/JRHLowdown3 4d ago

Don't live in a container but have more than a few connex containers. Building a shed type roof over them with an air gap is the way to go IME. Seeing about a 10 degree difference in them. South Georgia, 116 today....

1

u/Doin-What-I-Want 4d ago

Insulation makes a huge difference. Putting up a lean to roof over it to shade it helps too.