using suntuf as the only roofing on a large shop? - Page 3

AC_Hacker · 11-11-13, 02:10 PM

Quote:

Originally Posted by skyking

So, you are thinking insulating board or something similar over the roof sheeting?
Like this?
3/4" Foil Faced Insulation Panel at Menards
That does pose a fastener question regarding the metal roof. I'd have to get a long enough fastener to reach through to the OSB to tie the metal down well.

Yeah, I was thinking of something like that... not any kind of super-insulation strategy (unless you want to be a certified insulation hero) but enough to allow the heat to build up for the water or water/glycol fluid.

The fastener issue is not a big deal, metal roofs go on over much thicker insulation than you are considering, all the time.

But where on the metal roofing will your fasteners go? Will that intrude onto your PEX channel?

-AC

skyking · 11-11-13, 02:56 PM

Here is what I am imagining:
Roof joists->OSB sheeting->3/4" foil board.
Hero-style R-26 minimum insulation between the joists below the OSB

there is a 1.5"x1.5" nailed around the roof perimeter, nailed to the OSB sheeting. The 3/4" foil is inside that.
Now we have a 3/4" space for pex. 3/4" pex might not be needed, but the dimension works for many reasons.
Lay out the pex and clip it down with U-clips and fasteners.
Use a horizontal pattern so you can see the pex. Don't worry about roof fastening yet.
Use small pieces of insulation to block between loops. Lay roofing over that, and shoot the screws down to the OSB. The standing seam roofing only gets screws on one edge, then the next sheet clips onto that piece and hides the screw.
It is easy to put in screws and not hit your tubing. Nothing is covering it.
Finish out the metal as normal.

AC_Hacker · 11-11-13, 04:17 PM

Quote:

Originally Posted by skyking

Here is what I am imagining:
Roof joists->OSB sheeting->3/4" foil board.
Hero-style R-26 minimum insulation between the joists below the OSB

R-26 for vaulted roofs isn't even code anymore in our fair PNW states. But since it's a shop, you should be due your proper respect.

Quote:

Originally Posted by skyking

there is a 1.5"x1.5" nailed around the roof perimeter, nailed to the OSB sheeting. The 3/4" foil is inside that.
Now we have a 3/4" space for pex. 3/4" pex might not be needed, but the dimension works for many reasons.
Lay out the pex and clip it down with U-clips and fasteners.
Use a horizontal pattern so you can see the pex. Don't worry about roof fastening yet.
Use small pieces of insulation to block between loops. Lay roofing over that, and shoot the screws down to the OSB. The standing seam roofing only gets screws on one edge, then the next sheet clips onto that piece and hides the screw.
It is easy to put in screws and not hit your tubing. Nothing is covering it.
Finish out the metal as normal.

Otherwise, it all sounds quite reasonable.

-AC

skyking · 11-11-13, 04:52 PM

I'll have a 15' by 56' roof pitch to work with, more or less. one 500' roll will give me a 14" spacing between runs. That's $400, the 3/4" foil backed board is another $400.
Under a grand difference. I will look at some charts and see if it would pay. We really don't do solar well up here

AC_Hacker · 11-11-13, 07:01 PM

Quote:

Originally Posted by skyking

I'll have a 15' by 56' roof pitch to work with, more or less. one 500' roll will give me a 14" spacing between runs. That's $400, the 3/4" foil backed board is another $400.

$400? how do you break that down?

Quote:

Originally Posted by skyking

I will look at some charts and see if it would pay.

I'd like to see what the charts tell you.

Quote:

Originally Posted by skyking

We really don't do solar well up here

Roger that... but we do get low quality solar. You need to have a goodly amount of temperature difference between your heated water and your radiating structure. It just so happens that a homemade heat pump can extract the heat and give you the delta-T, quite happily. The question is, will it supply heat at the rate you require. This is where reducing infiltration and increasing insulation becomes so important.

Also, if you have the land and the gumption, a ground source loop field can provide heat for you during the chill months, but during warm months, your PEX in the roof can gather warmth that you can stash in the ground (assuming you don't have serious water movement in the ground)... and it will cool your roof at the same time.

randen used the loop field to heat his shop near Toronto, and he built a homemade heat pump for that purpose.

He left a fairly well-documented trail...

BTW, I've kind of come into this thread in the middle... does your shop exist already? Are you building new? Are you renovating or are you planning out your ultimate shop?

-AC

AC_Hacker · 11-11-13, 07:23 PM

Hey skyking,

I was able to locate the study that I was referring to previously...

HERE IT IS!

It should provide much food for thought.

-AC

skyking · 11-11-13, 07:43 PM

as they say "you are the man"!
To summarize, they were able to extract about half as much as an exposed collector. I don't believe it was an evacuated tube high efficiency system they were comparing to though.
This shop is in planning stages. It will not be heated to the extent our house is.
I am very familiar with ground loop systems.
This is my brother's system in Yakima. I did all the ground work there.
http://ecorenovator.org/forum/geothe...m-install.html
I am contemplating that as well. He jacks solar heat into his ground system too.

That 400 was for just the tubing and nothing more. Same for the insulation. I was talking about the bare bones that went under the metal.

AC_Hacker · 11-11-13, 08:33 PM

[QUOTE=skyking;33144}...That 400 was for just the tubing and nothing more...[/QUOTE]

I can understand if you want to buy local and support your community, however there are some pretty good prices HERE.

-AC

rvCharlie · 12-26-13, 12:09 PM

Quote:

Originally Posted by MN Renovator

The color doesn't matter. Color affects how something absorbs light, not how it radiates or convects heat. Unless the radiator in a path to receive sunlight, the radiator will have the same output and the pattern of output will be the same.

Sorry; I'm a bit late to this party. The above statement disagrees with every scientific source I've checked. One source:
Thermal radiation - Wikipedia, the free encyclopedia

The concept of more efficient emission from a 'black' surface is supported even by the instructions for using non-contact thermometers, which say that more accurate readings can be obtained by painting the target black.

Can you back up your statement with scientific sources?

Charlie

Exeric · 12-31-13, 04:06 PM

I was thinking about this. Sometimes people wake up on the wrong side of the bed. I think both I and MnRenovator did on the particular day this interchange came up. I don't hold any grudges here and don't want to rehash this, though I appreciate the support for my view, regardless. But let's all let it go and move on and continue to be friends.

11-11-13, 07:23 PM	#26
AC_Hacker Supreme EcoRenovator Join Date: Mar 2009 Location: Portland, OR Posts: 4,004 Thanks: 303 Thanked 724 Times in 534 Posts	The Solar Study I was Referring To... Hey skyking, I was able to locate the study that I was referring to previously... HERE IT IS! It should provide much food for thought. -AC Attached Thumbnails __________________ I'm not an HVAC technician. In fact, I'm barely even a hacker...

11-11-13, 08:33 PM	#28
AC_Hacker Supreme EcoRenovator Join Date: Mar 2009 Location: Portland, OR Posts: 4,004 Thanks: 303 Thanked 724 Times in 534 Posts	[QUOTE=skyking;33144}...That 400 was for just the tubing and nothing more...[/QUOTE] I can understand if you want to buy local and support your community, however there are some pretty good prices HERE. -AC __________________ I'm not an HVAC technician. In fact, I'm barely even a hacker...

11-11-13, 02:56 PM	#22
skyking Helper EcoRenovator Join Date: May 2011 Location: Western Washington Posts: 91 Thanks: 47 Thanked 20 Times in 13 Posts	Here is what I am imagining: Roof joists->OSB sheeting->3/4" foil board. Hero-style R-26 minimum insulation between the joists below the OSB there is a 1.5"x1.5" nailed around the roof perimeter, nailed to the OSB sheeting. The 3/4" foil is inside that. Now we have a 3/4" space for pex. 3/4" pex might not be needed, but the dimension works for many reasons. Lay out the pex and clip it down with U-clips and fasteners. Use a horizontal pattern so you can see the pex. Don't worry about roof fastening yet. Use small pieces of insulation to block between loops. Lay roofing over that, and shoot the screws down to the OSB. The standing seam roofing only gets screws on one edge, then the next sheet clips onto that piece and hides the screw. It is easy to put in screws and not hit your tubing. Nothing is covering it. Finish out the metal as normal.

11-11-13, 04:52 PM	#24
skyking Helper EcoRenovator Join Date: May 2011 Location: Western Washington Posts: 91 Thanks: 47 Thanked 20 Times in 13 Posts	I'll have a 15' by 56' roof pitch to work with, more or less. one 500' roll will give me a 14" spacing between runs. That's $400, the 3/4" foil backed board is another $400. Under a grand difference. I will look at some charts and see if it would pay. We really don't do solar well up here

11-11-13, 07:43 PM	#27
skyking Helper EcoRenovator Join Date: May 2011 Location: Western Washington Posts: 91 Thanks: 47 Thanked 20 Times in 13 Posts	as they say "you are the man"! To summarize, they were able to extract about half as much as an exposed collector. I don't believe it was an evacuated tube high efficiency system they were comparing to though. This shop is in planning stages. It will not be heated to the extent our house is. I am very familiar with ground loop systems. This is my brother's system in Yakima. I did all the ground work there. http://ecorenovator.org/forum/geothe...m-install.html I am contemplating that as well. He jacks solar heat into his ground system too. That 400 was for just the tubing and nothing more. Same for the insulation. I was talking about the bare bones that went under the metal.

12-31-13, 04:06 PM	#30
Exeric Apprentice EcoRenovator Join Date: Aug 2012 Location: California Posts: 274 Thanks: 19 Thanked 37 Times in 28 Posts	I was thinking about this. Sometimes people wake up on the wrong side of the bed. I think both I and MnRenovator did on the particular day this interchange came up. I don't hold any grudges here and don't want to rehash this, though I appreciate the support for my view, regardless. But let's all let it go and move on and continue to be friends.