One vs one and half story, a heating and cooling question.

[Dallas2build]

Ok guys I need some serious help.  I am at that point where I am second guessing my entire plan.  My reason for the rethinking is the concern with heating and cooling the one and half story cabin. 

Here is the scenario.  My cabin will be in southeastern Oklahoma where heating is really only required 4 months of the year and 2 of those months it is just needed over night and early mornings.  For heat I will be using wood, with a couple of propane wall heaters for instant heat upon arrival or evening out cold rooms.  My real concern with heating is that by the time the downstairs is comfortable the loft will be a firey inferno and unbearable.  My next big concern is the cabain will be off the grid and although I will have a battery bank running a couple ceiling fans over night there is no cooling except for the breeze.  This makes me concerned that the loft will be a firey inferno during the late spring and early fall months as well.  So I begin to wonder if I am building a loft that will only be comfortable for use about 2 months out of the year.

Thoughts??   

[John Raabe]

In a house with 2x6 walls, good insulation, airsealing and good windows you are not going to see those old vertical temperature differences you get in leaky uninsulated structures.

Our upper level is completely open to the cathedral ceiling area of the main floor where the wood stove sits. The normal temperatures when the wood stove is going is that the upper floor hall is perhaps 4 -5ºF warmer than the main level. We keep the upstairs bedroom doors closed since we like cooler sleeping rooms. They usually run 4 or 5º cooler than the main floor living areas, so the door can be used to control the room temp.

The house is pretty evenly heated by the single stove - however, this takes several hours when a cold house is first heated up.

[ScottA]

Our loft is prefectly comfortable. All that's needed is a cieling fan to circulate the air and that's only needed when it starts to get hot. In the winter it's the same story. We are running A/C now ( I don't see how anyone could live in OK in the summer without A/C) It's maybe 1-2 degrees warmer in the loft with the cieling fan on low.

[Dallas2build]

Thats a good point John.  It's not like I will need to have the stove blazing away to heat the downstairs if I do a good job insulating.  It will be 2x6 build.

(I don't see how anyone could live in OK in the summer without A/C)

I couldn't imagine a house without a/c.  I ususally don't even go up there during July and August.  My buddy that has a cabin there close that I usually stay with tried a small a/c but it is still hard to cool off the cabin to sleep at night.  Without running it all day it's almost impossible to cool it off and make it comfortable enought to sleep.  He doesn't like to leave the generator running all day and night so it just doesn't work out very well.

My concerns are definetly more towards being cool than staying warm.  That's why I tried to design for maximum airflow through the rooms.

Question:  I will have cathedral ceiling thoughout, what if I put in a couple dormers in the roof line and designed a way to open the windows from the floor.  Would that create a good airflow up in the peak and help the heat escape and make late spring and early fall visits more comfortable?

[rwanders]

Have you considered a "whole house fan" in the upper wall or roof ? ----they will usually quickly exhaust hot air and make the start up of AC a lot more efficient. After a short time, you shut off the fan and let the AC catch up.

[Dallas2build]

Have you considered a "whole house fan" in the upper wall or roof ? ----they will usually quickly exhaust hot air and make the start up of AC a lot more efficient. After a short time, you shut off the fan and let the AC catch up.

I'm off the grid.  No A/C and no electricity to run a large attic fan.  I have the generator and could turn it on to exhaust the heat and then turn it off I guess.

Anyone have a thought on the dormers?

[rwanders]

Dormers and opening windows both there and on the first floor would certainly help to cool off the home-----any arrangement that mimics a chimney will do that. Consider the prevailing wind direction when you place the building and windows too----opening upper windows on the downwind side and lower ones to catch the wind may be most effective at drawing out hot air.

[kenhill]

Add a cupola at the top of your stairs for ventilation and scenery viewing.

[Dallas2build]

  Rwanders and Kenhill thank you!  I will design a good looking cupola that will create adequate airflow and use it to create the chimney effect as rwanders said.  It will draft the heat right out of the top.  It's even better than dormers because it is in the peak.

I have all kinds of ideas now about how to build it, make it water tight, open and close, etc...  This will make the difference I was looking for.  Thanks again guys!

[Dave Sparks]

We keep the upstairs bedroom doors closed since we like cooler sleeping rooms. They usually run 4 or 5º cooler than the main floor living areas, so the door can be used to control the room temp.

Words of wisdom John!
My better half and I are fairly smart people but it still took 2 years to figure out the door trick! We ruined a few happy hours discussing why it was cold in the living space or too warm in the sleeping space!

To the OP, also consider your soffit vents and the wind! If you are on a hill, or if there is a prevailing afternoon wind the soffits can be oriented to maximize late afternoon cooling of the attic. If you get it right there will be a blanket of cool air over your insulation and the roof heat will still go out the gable or ridge.

[Dallas2build]

That is a great ideal, but I was planning for an open loft so I wouldn't have the ability to close off the upstairs rooms.  I think the cupola will give me what I need for cooling in the spring, summer and early fall.  As far as winter goes you guys have convinced me there won't be a drastic difference between the zones if well insulated.  So I shouldn't have the wood stove so hot to heat downstairs that it's too hot to sleep in the loft.  If it gets too hot when it's time to hit the loft for bed I can open a cupola window for a few minutes and cool it right off.

The cabin will have a cathedral ceiling throughout and no attic space.  I'm looking at using the same 16" deep manufactured i-joist for my rafters that I am using for floor joist.  If I do that I will have a lot of room for insulation between my decking material and the ceiling material as well as an airflow space between the top of the insulation and the decking.  Does anyone have any thoughts on that?  Won't that provide an optimum protection from the radiant heat?

[rwanders]

   If you google solar powered attic fans you will find some that may be of use.