Should the door be open?

It’s about 34°F (1°C) outside. We got a foot of snow last night but now it’s clear, sunny, and bright. I opened the front door for a while and let the cats lie on the dark tile mud-floor, basking in the sun.

Many photons streamed through the storm door and generated heat on the tile and wood floors. But also, warm air flowed out around the storm door.

When *should* I leave the door open? What factors into the balance?

It’s a log home that relies on thermal mass instead of insulation if that matters. (And I’m not prepared to solve partial differential equations to get the real answer — I’m looking for “rule of thumb” level analysis. )

Is the door a solid door Christopher, so that when closed you don't get solar gain?

Good one — it has a window in it, so I could get 1/3 the solar gain and all the insulation advantages! But it sure seems like a *lot* less gain. Maybe because it misses the black tile.

Fresh air is good. Houses get stuffy and dusty in winter.

The air you're getting right now is probably as clean as it gets -- no dust or pollen or bugs, and possibly a few negative ions from the storm. All good stuff.

I don't air my house enough because I pay for my heat (natural gas) which ain't cheap. I tend to take *myself* out into the fresh air.

We keep our door open and the storm door can act like a window to the world.  And so the cat can tell us that she wants to come in ....

Usually keep the main door closed and let the sun come through the storm door/glass.

Rule of thumb: if it’s sunny and calm, a few minutes open is fine, but at 34°F the warm air loss usually beats the solar gain.

Best bet:
Closed glass = gain heat
Open door = lose heat

Chris,   Just to be clear, that's a glass storm door on the outside, not a screen door, correct?   Even as a glass storm door has low insulating value, I think on sunny days the gain is pretty worthwhile, just in sunlight and effect on mood!  I'm assuming that is south facing....just like us, I suppose there are days to be concerned about nasty SE and SW winds, but our worst right now are the NW ones Douglas A is sending down from the prairie provinces.  Even as it didn't clear 25F today, the sun was allowing for puddling around the yard and driveway....makes for muddy dogs, but the geese and chickens are pretty happy.  [Unfortunately, we are dealing with a rogue mink lately and learning which houses need serious refurbishing this summer! ]   Nevertheless, on days like this, my wife will open the large south-facing garage door on the insulated barn and the sun does wonders!  Pigs, chickens, dogs all stretched out along the entryway enjoying the light and heat.  What it does for attitude compensates in my mind for a bit of lost home heat.   Edited to add, not looking forward to near zero again on Sunday and Monday night....

John Weiland wrote:I suppose there are days to be concerned about nasty SE and SW winds, but our worst right now are the NW ones Douglas A is sending down from the prairie provinces.  

Hijack alert:

FEEL MY DIVINE WRATH! MWAHAHA!

Well not really, we got whacked by those near-hurricane winds last weekend. Trees snapped off and half the neighbourhood lost power. Serious chainsaw festival. Weirdly, up on our steep hill, we didn't have any damage at all. I did make points with neighbours lending my little RV 2kW genny so their fridges and freezers wouldn't spoil.

/End of hijack

Douglas Alpenstock wrote: ......near-hurricane winds last weekend. Trees snapped off and half the neighbourhood lost power. Serious chainsaw festival.  

We just had those last night and I don't know if they will be sustained on the way to Chris's location.  Funny thing is I had been chainsawing in preparation for the storm to arrive, then left some of the dead tree crowns dangling overhead in the branches of neighboring trees.  The wind took care of that!....all had worked loose from the high winds and now were easy pickin's on the ground for the smaller saw. As irritating as those high winds are for comfort and home heating, they dry out a thawing surface just itching to flood our basement.  So far, Red River down here looking pretty tame...but can't speak for its march towards Winnipeg.  Returning to topic, I don't think Chris's location gets the constant winds that we do, although they certainly have large forest blow-downs from severe summer storms.  But wind is an important modifier in the decision to keep doors closed or open.