Insulation Walls vs celing 1st

[dodge em]

i am running heated floor in a 15x30. Im in northeast ohio and on a limited budget and can do one or the other. Currently i have R5 + or so ceiling w/ 1 or 1.5 foam board and half the walls with r13 I did the walls that get hit with the winter wind.

i know the ceiling is going to be the ticket with a hot air heater as heat rises but heard here some time ago that radiant heat is a little different. but seeing as the ceiling is supposed to be R38+...

The foam board is all i have for a ceiling so the blow in would be on the foam board

 

[z28toz06]

I would do the ceiling first. The walls would be easy enough to do later as you get some cash. plus the whole heat rises thing.

 

[JC23]

I'd go with the ceiling first seeing how you have the floor heat. But what about running all your wires in the walls and ceiling? Is that done already? If both are done, then it becomes a issue of retaining heat that rises.

I'm in NE Ohio, where are you? And welcome aboard!

 

[fflintstone]

Physics 101 HEAT DOES NOT RISE!!!! Heat radiates equality from its source migrating to cold.
Hot AIR rises. In a closed room this is caused by convection.
Since you have a radiant FLOOR heating system it makes the most sense to do the walls first.
If you had forced air heat it would make more sense to do the ceiling first.

 

[dodge em]

im in hartville (by akron/csnton)
all my wiring is handled or able to be with insulation not a problem.

ok if the heat is covection and i do the walls now, what precent of heat eff gain will i see when i do the ceiling?

My issue is last year i was heating with a 6500watt house water heater and was running $284-$320 a month to heat.
a sewer line went south in the winter and i had to run a new line and saw the option to run the gas line as the septic is just past the shop...

So i upgraded to a 40gal 32k or 40k btu hot water tank. but it warmed up so i dont know what my cut in energy bill will be.

I had winter work last year so its not a issue but this year i dont so the garage may go cold.

thanks

 

[fflintstone]

im in hartville (by akron/csnton)
all my wiring is handled or able to be with insulation not a problem.

ok if the heat is covection and i do the walls now, what precent of heat eff gain will i see when i do the ceiling?

My issue is last year i was heating with a 6500watt house water heater and was running $284-$320 a month to heat.
a sewer line went south in the winter and i had to run a new line and saw the option to run the gas line as the septic is just past the shop...

So i upgraded to a 40gal 32k or 40k btu hot water tank. but it warmed up so i dont know what my cut in energy bill will be.

I had winter work last year so its not a issue but this year i dont so the garage may go cold.

thanks

Sorry I get a bug up my… when people say “heat rises”. The more you insulate the less heat will migrate to the cold outside air. The gas WH should be a cost savings over electric. As I said (my opinion only)(with radiant floor heat) if I were to add either or, I would do the walls first and then the ceiling next year. The cost payback when you insulate is beyond “top of my head” knowledge. It will be most cost effective (return on the dollar) to get to a minimum level in the ceiling. Example adding R13 may save you 15% but doubling that to a R26 may save 21%. Get the point.
I went from R19 in an 800SF house to R49 the first year my heat bill dropped a little. the second year it was back up to what it had been, but the cost of gas per CF had almost doubled.

 

[nate379]

If you plan on using that garage any time in the winter and having heat, I would not let it go cold. It will take a solid day at least to get the slab up to temp and the building warm.

I keep my garage at 55* and it's plenty warm to work in at that temp and I don't have to worry about anything freezing up.

I would first do the walls that don't have anything and go from there. Around here R21 walls and R45 ceiling is normal. Might actually be min code even.

 

[dodge em]

My walls are 2x4's spaced un even ones 13in and the next 22in OC and anyhitng inbetween like that when i bought it, thats for sure.

I did my house 3in the the attic to 14in and did draft control around, dropped my bill by about half

what would be the expected savings switching to natural gas as i did? any one have a rough precent based off experience?

thanks

 

[dodge em]

O and that was my second thought about keeping the stat all the way down, 50*f or so. I bought a vent free 32k btu heater $35 garage sale and was thinking turning that on to heat up to take the chill off when i go out.

But im spoiled now an may miss my winter concrete temper pedic

 

[Kevin54]

Do the walls first, but toss some drywall on the ceiling if you do not have any. Whether it keeps the heat from rising up to the rafters or the cold falling from the attic, at least you won't be sending ALL the heat up into that space. Then you can insulate it next year.

Never mind...just went back and re-read. You have foamboard on the ceiling

 

[walrus]

O and that was my second thought about keeping the stat all the way down, 50*f or so. I bought a vent free 32k btu heater $35 garage sale and was thinking turning that on to heat up to take the chill off when i go out.

But im spoiled now an may miss my winter concrete temper pedic

I would never run a vent free heater, too much moisture. when burned, propane produces a ton of water

 

[dodge em]

bought the remaining wall insulation tonight. Im gonna run with this and see what me bill will look like first before the ventfree. I was planing on using the vent free to warm it up a little not as a perminat heat source. and the moisture cant be much more then washing the truck in a in-floor heated garage... but i get the point

thanks for your guys s help, if any one knows the cost savings of natural gas over ele i would love to hear

 

[z28toz06]

Physics 101 HEAT DOES NOT RISE!!!! Heat radiates equality from its source migrating to cold.
Hot AIR rises. In a closed room this is caused by convection.
Since you have a radiant FLOOR heating system it makes the most sense to do the walls first.
If you had forced air heat it would make more sense to do the ceiling first.

Very true, however since the floor is the heat source/sink and it is insulated all around the perimeter, the heat coming off the floor will radiate up and the resultant warming air will rise straight up and warm the air column and very little heat will migrate or radiate to the walls, rather straight up and very little heat will be absorbed by the walls. So the only real effective way to cap the loss would be to insulate the ceiling. As the warm air that was rising reaches the ceiling and has no where to go, it will start to stack in the room. If you do the walls first, it will just form an insulated chimney sending the heat out up to and out through the uninsulated roof.

 

[fflintstone]

Very true, however since the floor is the heat source/sink and it is insulated all around the perimeter, the heat coming off the floor will radiate up and the resultant warming air will rise straight up and warm the air column and very little heat will migrate or radiate to the walls, rather straight up and very little heat will be absorbed by the walls. So the only real effective way to cap the loss would be to insulate the ceiling. As the warm air that was rising reaches the ceiling and has no where to go, it will start to stack in the room. If you do the walls first, it will just form an insulated chimney sending the heat out up to and out through the uninsulated roof.

WRONG!
With uninsulated walls the heat radiating from the slab will be drawn to the side walls and start a convection losing heat thru the walls and creating a downdraft it the center of the room (an updraft along the un insulated walls). The air will convect in a circular pattern all the way around the perimeter of the room.
If you insulate the walls, and create ”an insulated chimney” there will be less convection, as the air warmed by the floor will rise SLOWLY towards the already lightly insulated ceiling.

 

[DzNuts]

WRONG!
With uninsulated walls the heat radiating from the slab will be drawn to the side walls and start a convection losing heat thru the walls and creating a downdraft it the center of the room (an updraft along the un insulated walls). The air will convect in a circular pattern all the way around the perimeter of the room.
If you insulate the walls, and create ”an insulated chimney” there will be less convection, as the air warmed by the floor will rise SLOWLY towards the already lightly insulated ceiling.

I think you're reaching!

 

[z28toz06]

Originally Posted by fflintstone
WRONG!
With uninsulated walls the heat radiating from the slab will be drawn to the side walls and start a convection losing heat thru the walls and creating a downdraft it the center of the room (an updraft along the un insulated walls). The air will convect in a circular pattern all the way around the perimeter of the room.
If you insulate the walls, and create ”an insulated chimney” there will be less convection, as the air warmed by the floor will rise SLOWLY towards the already lightly insulated ceiling.

I think you're reaching!

I agree, and fflintstone, what's up with the pink "wrong" in bold? what else are you trying to tell us?

That whole insulated chimney theory is really reaching. it's not going to slow any cold air falling from the ceiling.

 

[stealthbob]

Semantics...

Hot Air rises and heat dissipates in any direction, theoretically correct but...

That only exists in a Vacuum but in an atmosphere the heat is in the air which when heated rises.

It will rise and the cold will fall because our Garages contain atmosphere.

The quandary would be mitigated greatly by adding a fan to circulate the air thus rendering the up or side argument moot. It ALL needs to be insulated....

 

[Teken]

Semantics...

Hot Air rises and heat dissipates in any direction, theoretically correct but...

That only exists in a Vacuum but in an atmosphere the heat is in the air which when heated rises.

It will rise and the cold will fall because our Garages contain atmosphere.

The quandary would be mitigated greatly by adding a fan to circulate the air thus rendering the up or side argument moot. It ALL needs to be insulated....

I have to affirm that thought process as well . . . I have lived in all kinds of homes with attached garages.

Some had bare bones, others had partial insulation, others had the full meal deal.

Insulation is only one of the key components, heating is the next, and circulation of that heat with in the insulated space is last.

Anyone who doubts this need only join me in my garage when the mercury hits -40'C, then they can tell me how all three don't play a important role in the heat system . . .

 

[ryaninmichigan]

thermadynamics. hot air rises not heat. Heat is energy it seeks out that that does not have energy. (cold = lack of energy) heat moves vertically and horizonaly. If that is not so then tell me why overhead radiant works?

 

[dodge em]

well a little update. Pulled a all nighter and got the walls done. I do have a fan by the way.

what are the three keys? insulate 1 walls, 2 ceilling, 3 a fan?

Im going to try to get the ceilling up to R21 from 7 but thats the best i may be able to do.