Using attic heat for the house - Page 8

Daox · 11-29-10, 12:56 PM

Just a quick little update since it has been a while. I've put this project on hold since I have still been monitoring attic temps and the attic isn't getting anywhere near warm enough to do any house heating as is. As spring approaches, I'll start back up with it.

Ryland · 11-30-10, 08:29 AM

It seems like an air source heat pump that is ducted and has dampeners that allow it to vent outside of the attic and even pull cool air from outside of the attic from the north side of the house in the summer if you wanted to use it for cooling as well, would work well.
you would have to make sure that there was a way for it to drain of course without freezing because on a sunny day in the winter it might be the coolest thing and condensation could become an issue.

Daox · 03-29-11, 08:50 AM

Well, spring is on its way, and as I said I wanted to start this project up around now. It was a nice sunny day yesterday and when I got home I look at my attic thermometer and it read a nice 61F. So, its getting close to being warm enough to heat the house (I keep it @ 60F during the day).

So, a real quick recap here. I have made a platform with two fans on it to blow hot attic air down my chimney and into my kitchen.

I have also made a base that is now mounted on the chimney that I can screw the fan platform to.

So, it looks like the next step is to add a differential temperature controller to control when to turn the fans on automatically. I also need to add and some other things like an air filter to the system, and I'd like to add some plumbing to suck air from the top of the attic to get the hottest air.

Piwoslaw · 03-29-11, 09:12 AM

Looks nice. Will you run it manually before you get the automatics set up?

What height is the attic's temperature sensor at? (Higher or lower than the fans?) What outdoor weather are you having now?

Daox · 03-29-11, 09:32 AM

Quote:

Originally Posted by Piwoslaw

Looks nice. Will you run it manually before you get the automatics set up?

No, I don't think so. I might mess with it on the weekend, but for the most part, the heat I want to harvest is there during the day while I'm at work. So, I'm going to need it fully automated in order to get the most out of it.

Quote:

What height is the attic's temperature sensor at? (Higher or lower than the fans?)

The sensor is currently just sitting on the platform I made in my attic when I put in more insulation. Its ~6 inches above the insulation. So, the top of the attic I'm sure is a bit warmer. The fans will sit ~2ft above the insulation I'd say, so they'd be higher and at a warmer spot.

Quote:

What outdoor weather are you having now?

Well, its been below freezing in the morning at around 15F/-9.5C, but gets to about 35F/1.5C during the day if its nice and sunny.

Daox · 03-29-11, 10:50 AM

Yeah, the back flow preventers will be added. I have a couple of them.

Daox · 03-29-11, 09:58 PM

I worked on this a bit tonight. I realized I'd need to seal the exhaust pipe, and I'd have to do that with metal to handle the heat. So, I sectioned off an area with a 2x2 so I can seal it off separately. I mounted that 2x2 tonight.

The next step is to add some ducting/framing for a filter and add the dampers to that same frame. I also need to seal the base of the frame between the brick and frame better. It is not air tight right now. Some great stuff or just caulk will do the job nicely.

I also pretty much finished up the design for the thermal differential controller that I'll be using on this project. Its a nice simple setup that should work very nicely.

ThomSjay · 03-31-11, 11:14 PM

This is an interesting project.

I was wondering if the chimney is drawing heat from the kitchen. Would it make sense to put some rigid insulation against the chimney in the attic?

Daox · 04-01-11, 07:02 AM

I'm sure the chimney is drawing some heat through natural convection and conduction through the brick. However, I do have the hole in the kitchen blocked with rigid foam and sealed with caulk for the time being. When I did the insulation in the attic they did have it wrapped in fiberglass and I never put it back on. Once I'm done here I'll probably throw it back on.

Daox · 04-02-11, 01:13 PM

I've been working on the fan setup this morning. I got mostly everything wired and ready to go. See my thread on the thermal differential controller to see the wiring schematic for it.

Here it is all wired up. I've only attached the temperature sensor that will be in the attic. The one that will be in the kitchen will be on the other end of the spool of wire.

Next, I went up into the attic to finish sealing around the water heater vent pipe. I cut two pieces of steel sheet, and then sealed it all with high temperature silicon sealant.

The next thing to do was mount up the fan assembly with electronics. The temperature sensor is the thing hanging from the cross member. For now, I am just going to get it going. If it works well I'll add the rest of the stuff we've talked about (filter, dampers).

11-29-10, 12:56 PM	#71
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Just a quick little update since it has been a while. I've put this project on hold since I have still been monitoring attic temps and the attic isn't getting anywhere near warm enough to do any house heating as is. As spring approaches, I'll start back up with it. __________________ 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.

03-29-11, 08:50 AM	#73
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Well, spring is on its way, and as I said I wanted to start this project up around now. It was a nice sunny day yesterday and when I got home I look at my attic thermometer and it read a nice 61F. So, its getting close to being warm enough to heat the house (I keep it @ 60F during the day). So, a real quick recap here. I have made a platform with two fans on it to blow hot attic air down my chimney and into my kitchen. I have also made a base that is now mounted on the chimney that I can screw the fan platform to. So, it looks like the next step is to add a differential temperature controller to control when to turn the fans on automatically. I also need to add and some other things like an air filter to the system, and I'd like to add some plumbing to suck air from the top of the attic to get the hottest air. __________________ 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.

03-29-11, 09:12 AM	#74
Piwoslaw Super Moderator Join Date: May 2009 Location: Warsaw, Poland Posts: 964 Thanks: 190 Thanked 111 Times in 87 Posts	Looks nice. Will you run it manually before you get the automatics set up? What height is the attic's temperature sensor at? (Higher or lower than the fans?) What outdoor weather are you having now? __________________ Ecorenovation - the bottomless piggy bank that tries to tame the energy hog.

03-29-11, 10:50 AM	#76
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	Yeah, the back flow preventers will be added. I have a couple of them. __________________ 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.

03-29-11, 09:58 PM	#77
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	I worked on this a bit tonight. I realized I'd need to seal the exhaust pipe, and I'd have to do that with metal to handle the heat. So, I sectioned off an area with a 2x2 so I can seal it off separately. I mounted that 2x2 tonight. The next step is to add some ducting/framing for a filter and add the dampers to that same frame. I also need to seal the base of the frame between the brick and frame better. It is not air tight right now. Some great stuff or just caulk will do the job nicely. I also pretty much finished up the design for the thermal differential controller that I'll be using on this project. Its a nice simple setup that should work very nicely. Attached Thumbnails __________________ 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.

11-30-10, 08:29 AM	#72
Ryland Master EcoRenovator Join Date: Mar 2009 Location: Western Wisconsin. Posts: 913 Thanks: 127 Thanked 82 Times in 71 Posts	It seems like an air source heat pump that is ducted and has dampeners that allow it to vent outside of the attic and even pull cool air from outside of the attic from the north side of the house in the summer if you wanted to use it for cooling as well, would work well. you would have to make sure that there was a way for it to drain of course without freezing because on a sunny day in the winter it might be the coolest thing and condensation could become an issue.

03-31-11, 11:14 PM	#78
ThomSjay Helper EcoRenovator Join Date: Mar 2011 Location: Sarnia, Ontario, Canada Posts: 91 Thanks: 8 Thanked 2 Times in 2 Posts	This is an interesting project. I was wondering if the chimney is drawing heat from the kitchen. Would it make sense to put some rigid insulation against the chimney in the attic?

04-01-11, 07:02 AM	#79
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	I'm sure the chimney is drawing some heat through natural convection and conduction through the brick. However, I do have the hole in the kitchen blocked with rigid foam and sealed with caulk for the time being. When I did the insulation in the attic they did have it wrapped in fiberglass and I never put it back on. Once I'm done here I'll probably throw it back on. __________________ 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.

04-02-11, 01:13 PM	#80
Daox Administrator Join Date: Aug 2008 Location: Germantown, WI Posts: 5,525 Thanks: 1,162 Thanked 374 Times in 305 Posts	I've been working on the fan setup this morning. I got mostly everything wired and ready to go. See my thread on the thermal differential controller to see the wiring schematic for it. Here it is all wired up. I've only attached the temperature sensor that will be in the attic. The one that will be in the kitchen will be on the other end of the spool of wire. Next, I went up into the attic to finish sealing around the water heater vent pipe. I cut two pieces of steel sheet, and then sealed it all with high temperature silicon sealant. The next thing to do was mount up the fan assembly with electronics. The temperature sensor is the thing hanging from the cross member. For now, I am just going to get it going. If it works well I'll add the rest of the stuff we've talked about (filter, dampers). __________________ 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.

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