Using attic heat for the house - Page 2

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, 10:14 AM

Sorry, I haven't responded to a bunch of posts here.

Quote:

Originally Posted by Ryland

what about installing a heat pump? the attic should always be warmer then the outside temp.

That would probably work very nicely, but I'd like to start out as simple as possible for now.

Quote:

Originally Posted by Piwoslaw

If you have an unused chimney then go ahead and use it! It will save you the hassle and expense of running a duct between floors. Maybe make a circuit that checks temperatures and turns the fan on only when the attic is warmer than the kitchen? And Patrick is right about filtering.

Any chance of getting some insulation on that attic door?

Yeah, thats what I think I'm going to do. No filter for now. Its pretty clean up there so we'll wait to see if its a problem.

There is insulation above the door when its all closed up.

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.

09-18-10, 12:07 PM	#11
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	#12
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	#18
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	#19
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	#13
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	#16
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	#17
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	#20
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.