Best wall configuration for passive solar doghouse.

I'm building a passive dog house for our frigid winters.  The dimensions are 4'x8', 8' wall on the south, and 6' wall on the north.  I have three ideas for the south-facing wall.  I'm trying to decide which will work best.  

1) Build a regular stick frame doghouse.  The south wall would just be a solar heater, the type lots of people build with two layers of black metal screen, a cold air intake vent on the bottom and a vent on the top for heated air to blow into the doghouse.  Pros are, it's quicker and easier to build, the materials are cheaper, and it's a tried and true method of heating a building.  Cons are, there is nothing to hold the heat, so it will cool fairly quickly after the sun goes down, and that is very early here, usually by 4PM.  That isn't a huge problem because I bring the dogs in at night anyway, but it would be nice if they didn't have to come in at 5 every night.  The other con is that is may become too warm on sunny days.  My hoop house greenhouse can hit 100 F when it's 20 F outside on a sunny day.  Not what I want for a doghouse.

2) Build the same regular frame doghouse but instead of a regular framed wall at the south end, build the solar heater, but rather than a black painted box with screen as a heat absorber, build a brick wall with the bricks painted black.  Some bricks could be left out top and bottom so it would still draw in cold air from the bottom and vent the hot air into the dog house at the top.  The idea is, it would still act just like a passive solar heater, but the bricks would absorb a large amount of heat to be radiated out when the sun goes down.  That would be the pro of course, along with the fact that the bricks should absorb a lot of the heat and keep the doghouse from getting too warm.  Drawbacks are, the bricks may cool so much at night that the sun can't heat them up and the doghouse would stay cold, maybe colder than if they had nothing but an insulated house and their body heat.  I don't want to create a freezer.  (Maybe this is a trombe wall?)

3) Same as above, but without leaving any bricks out, thereby removing the solar heater aspect of it and just using the sun to heat the brick wall, and the brick wall to heat the interior.

Anyone have any knowledge that can help me decide the way to go?  Ideally, I would build all three and just test, but I don't have the time or money to do that, so I'm hoping to get input from anyone with any ideas of which of these is best, or something different altogether would be better.

Hey Trace!
I assume you are insulating the doghouse...

Easy way to modulate the temp might be a bimetal greenhouse vent.

Something I have heard of used (although I have not made one) (AND I'm not finding it right now) (Check https://www.builditsolar.com/   )    is to have the air intake up off the floor, to stop the air from siphoning when the heat is not pulling it up.

Good luck with having warm dogs! But then how do you warm your bed if your dogs aren't there? :D

Yep, all the other walls are insulated.  I have those self opening greenhouse vents, but if I could find a way to store the heat and use it for some time after the sun goes down, that would be ideal.  

I use a piece of plastic over the top vent that closes when heat isn't circulating, and stops the flow from reversing at night.  Builditsolar is the placed I learned about these passive solar heaters :)

Yay! sounds like you read the same things I do :D
Thinking on it, I think I'd skip the bricks totally, as they are a complex to debug wild card in this, and make sure the floor is thermally broken off the ground.

Hi Trace,
Could I ask what kind of dogs? I live in Maine with some pretty cold winters, and our dogs were outside most of the time. We build a small insulated doghouse with a small door and put some straw in. The bigger the doghouse, the more heat you need. For this size dog and doghouse, their own heat with the insulated sides was plenty... we never needed additional heat.

Having said that... there are some short hair dogs that don't grow thicker fur... so that is a whole different thing.

Hey Matt, I have a LGD that can stay out in any weather above -20F.  Also have an English Mastiff, but she is a house dog.  The dog I'm concerned with is a Presa Canario.  I would like him to be able to be outside, but they aren't equipped for Wis winters :)