Using attic heat for the house - Page 2

Daox · 09-17-10, 06:15 PM

Its been roughly an hour now. I checked the temperature in the room and it has risen a bit over 2 degrees.

Daox · 09-18-10, 12:07 PM

I only had about another 45 minutes before I had to leave last night. So, in just under 2 hours of blowing the attic air down, it brought the temp up from 68.5 to around 71.5. Not too shabby if I do say so. Well worth looking into IF the temperature gets high enough in winter.

Daox · 09-21-10, 09:22 AM

I did this again last night. I wasn't very sunny yesterday, but the attic was still 72 and the upstairs was 66. So, I wanted to see what a 6 degree difference would do to me. ~2 hrs later the upstairs was 67.5 and attic was ~70. With so little temperature differential I didn't think there was much benefit, but I was happy to see the temp go up 1.5 degrees.

So, going forward I'm thinking of improving the setup. I think the next easy step would be to move the fan into the attic and set it on top of the cutoff chimney. I recently bought a remote outlet control for another project, but I'm thinking it would be perfect here for manual control. When I notice its warm up there, I flick it on and have warm air blowing down into my kitchen. Of course I'll need to unblock the previously blocked hole.

Ideas, thoughts?

Xringer · 09-21-10, 10:08 AM

Is there an all-season attic-vent-fan product on the market with bi-directional fans,
that's insulated, with a flap that shuts during winter nights.?.

It would be nice to clear out indoor hot air in the summer and suck down warm air on days like this..

Daox · 09-21-10, 10:16 AM

Quote:

Originally Posted by Xringer

Is there an all-season attic-vent-fan product on the market with bi-directional fans,
that's insulated, with a flap that shuts during winter nights.?.

It would be nice to clear out indoor hot air in the summer and suck down warm air on days like this..

That is a great idea! I need to plug the chimney up anyways as I'm sure its a source of heat loss in the winter.

Anyone have any ideas on what products could be used like this? I'd imagine a bi-directional flapper door wouldn't be the easiest thing to come by.

Xringer · 09-21-10, 10:58 AM

It's 70 outdoors, 72 in my PC room right now (good solar), 66 in the basement and about 89 in the attic.

I have the pull-down door open about 8", so it doesn't get real hot up there..
Mainly, I want fresh dry air circulating in the basement. (for now).

When that pull-down door is sealed in the winter, it gets pretty warm up there..
Sun hitting any part of the roof will help keep the snow melting.. From the peak down.

I think my summer setup is okay, but I'll have to see if I can use some of that
attic heat for winter space heating.

skyl4rk · 09-21-10, 02:51 PM

Use an arduino or other microprocessor: When the attic is greater than 72 degrees and the house is less than 70 degrees, turn the fan on.

Daox · 09-21-10, 05:01 PM

Yeah, thats probably the way I'll go eventually if all the manual testing works out.

Daox · 09-23-10, 07:23 AM

So, I checked my chimney the other day. The opening is actually about half the size of my box fan. So, I'm thinking it would be a good idea to find some other fan for it. So, I'd imagine a squirrel cage fan would probably work better for this application since they're normally used for hvac stuff. I'm guessing because of their ability to create a higher pressure differential? Does anyone have any suggestions?

Patrick · 09-23-10, 08:36 AM

If you're going to use a squirrel cage fan, you can run it down the chimney since the discharge area is typically a lot smaller than a box fan. And it does produce a higher pressure differential than an axial fan.

09-17-10, 06:15 PM	#1
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Its been roughly an hour now. I checked the temperature in the room and it has risen a bit over 2 degrees. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

09-18-10, 12:07 PM	#2
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	I only had about another 45 minutes before I had to leave last night. So, in just under 2 hours of blowing the attic air down, it brought the temp up from 68.5 to around 71.5. Not too shabby if I do say so. Well worth looking into IF the temperature gets high enough in winter. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

09-21-10, 09:22 AM	#3
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	I did this again last night. I wasn't very sunny yesterday, but the attic was still 72 and the upstairs was 66. So, I wanted to see what a 6 degree difference would do to me. ~2 hrs later the upstairs was 67.5 and attic was ~70. With so little temperature differential I didn't think there was much benefit, but I was happy to see the temp go up 1.5 degrees. So, going forward I'm thinking of improving the setup. I think the next easy step would be to move the fan into the attic and set it on top of the cutoff chimney. I recently bought a remote outlet control for another project, but I'm thinking it would be perfect here for manual control. When I notice its warm up there, I flick it on and have warm air blowing down into my kitchen. Of course I'll need to unblock the previously blocked hole. Ideas, thoughts? __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. Last edited by Daox; 09-21-10 at 09:49 AM..

09-21-10, 05:01 PM	#8
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Yeah, thats probably the way I'll go eventually if all the manual testing works out. __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

09-23-10, 07:23 AM	#9
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	So, I checked my chimney the other day. The opening is actually about half the size of my box fan. So, I'm thinking it would be a good idea to find some other fan for it. So, I'd imagine a squirrel cage fan would probably work better for this application since they're normally used for hvac stuff. I'm guessing because of their ability to create a higher pressure differential? Does anyone have any suggestions? __________________ Current project - To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts. & To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.

09-21-10, 10:08 AM	#4
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Is there an all-season attic-vent-fan product on the market with bi-directional fans, that's insulated, with a flap that shuts during winter nights.?. It would be nice to clear out indoor hot air in the summer and suck down warm air on days like this..

09-21-10, 10:58 AM	#6
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	It's 70 outdoors, 72 in my PC room right now (good solar), 66 in the basement and about 89 in the attic. I have the pull-down door open about 8", so it doesn't get real hot up there.. Mainly, I want fresh dry air circulating in the basement. (for now). When that pull-down door is sealed in the winter, it gets pretty warm up there.. Sun hitting any part of the roof will help keep the snow melting.. From the peak down. I think my summer setup is okay, but I'll have to see if I can use some of that attic heat for winter space heating.

09-21-10, 02:51 PM	#7
skyl4rk Helper EcoRenovator Join Date: Sep 2010 Posts: 66 Thanks: 3 Thanked 6 Times in 4 Posts	Use an arduino or other microprocessor: When the attic is greater than 72 degrees and the house is less than 70 degrees, turn the fan on.

09-23-10, 08:36 AM	#10
Patrick Apprentice EcoRenovator Join Date: Jul 2010 Location: East Coast of Florida, USA Posts: 149 Thanks: 2 Thanked 5 Times in 5 Posts	If you're going to use a squirrel cage fan, you can run it down the chimney since the discharge area is typically a lot smaller than a box fan. And it does produce a higher pressure differential than an axial fan.