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gbwillson

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Reply with quote  #11 
Jim-

How many SF is your home? It would also be helpful if you would draw up a floor plan which would help determine the best input/output locations as well as if more than one heater will be needed.

While attachment directly to the side of the house is ideal, it may not be the best, regardless of what the owner says about you treating the house as your own. Moving the collectors seasonally means you have to have a place to store them. So I would suggest a compromise similar to what Don(DBC) did here:
http://simplysolar.supporttopics.com/post/don-cs-new-2x16-zeropass-collector-8071547?&trail=10

The beauty of his mounting is that other than a few bolts screwed into the mortar between the bricks, he doesn't do any damage to the wall. He mounted the collector far enough away from the wall to allow some adjustability as to where they enter the wall. Which in your case, could be the window. Your windows look like the upper half is fixed, and the lower portion is a slider. So a board could be cut to the size of the sliding portion. Remove the sliding portion of the window and replace it with the duct opening board. This board could have a layer of insulation as well. And be sure to make the board secure so as someone can't gain easy entry to your home. And if you look at his design, it would be very easy to make the lower arms that extend from the house longer. This would allow the lower edge of the collector to be slid out or tilted to the proper angle for heating, and returned vertical when not in use.

How much heat you can expect from a 4x16 or 4x20 ZP? You should think of any solar heater as supplementary. Think of it like a little electric space heater that runs all day while the sun is out. Or more accurately, it is like 3-4 space heaters, each putting out just over 5,000BTU's per hour. So you could easily be putting out 15,000-20,000 BTU's per hour  or more from your ZP heater! It will not completely replace the main source as it won't run at night or when it's cloudy. However...You do live in a mild sunny location, at a high elevation where solar conditions would be near optimal. And with the mass in the walls, the house should hold heat nicely once warmed. But as Willie mentioned, you may end up raising the air temp in the home during the day. As an example, I normally blow warm air into the basement, which in turn warms the house. But for giggles, I routed one of my ducts in through a kitchen window. Let's just say was wearing only shorts as the temp in the house was almost 90˚. The 900sf house cooled much fast than normal too, as the heat wasn't stored in the basement ceiling mass like normal. But you might like the temps at home like that, as long as it warms the house, and especially the floor. 

And while the warm air entering the home will rise, you can deflect in towards the floor. It would also be best to have the intake pulling the cold air off the floor. This way you are maximizing the exchange of the coldest air in the home for the warmest! And once this warmth is absorbed by the walls, the home should maintain a comfortable temp until morning. 


Greg in MN

stmbtwle

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Reply with quote  #12 
You could try something like this. This is a water-based collector but the same basic setup could be adapted to an air collector. It's adjustable through nearly 90°. Pictured is the winter position, at the moment it's vertical for minimum harvest in the summer.
https://simplysolar.supporttopics.com/post/show_single_post?pid=1294026697&postcount=1&forum=268066

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Willie, Tampa Bay
stmbtwle

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Reply with quote  #13 
Jim, reading back on your original post, I realized that you ALREADY HAD several water-based panels, drums, and a pump. Even with the (usual) cost advantages of air, you might be ahead by using what you have rather than start over.

Your panels could be set up outside (if they're metal even on the roof) and the hot water pumped in through a small hole in the wall to a fan coil or baseboard heater made out of tubing or pipe.  It would be relatively easy to get heat into every room that way with minimal impact on the structure.  

As you already have plenty of interior mass, I think (for now at least) I'd skip the plastic drums and run the output from the solar collectors directly inside to heat during the day.  This would be more efficient too.  If you later want to "time shift" your heat, you can install the drums in an insulated outside enclosure.

Suppose you were to drill a couple 3/4" holes in the wall at floor level, (I'd drill from inside to get the level right), and connect a length of cpvc pipe, PEX, or irrigation tubing which is then run along the edge of the floor against the wall. Pump hot water from the collectors through the pipe and back to the collectors.  The pipe would heat floor-level air which would rise along the walls, in turn heating them.  

For a trial system there's no reason you can't run the pipe/hose through the window and thus avoid drilling at all.   

As it uses equipment you already have, I think it might be a good place to start.

Here's my original thread; the system works well and has been in service for 3 winters now.
https://simplysolar.supporttopics.com/post/willies-solar-hot-water-space-heater-7257880?&trail=10

I think it could be simplified in your case by leaving out the water storage and by using a loop instead of the fan coil...  Something like this:

Solar heater for adobe home.jpg 

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Willie, Tampa Bay
gbwillson

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Reply with quote  #14 
Willie-

I agree that since Jim has already purchased parts for a water-based system he should give that first priority. But parts can be sold. The biggest issue with either air or water is distribution. A 1" hole through a wall is a heck of a lot less trouble than a large duct for air. But in either case, how do you gain access to even drill or cut the openings for either ducts or pipes? Now a setup like Jamie is working on, where the storage is outside, might have possibilities. But even if you enter the water lines into the house, you still need a way to distribute the heat throughout the home. Yes, a radiator, or baseboard heater could be installed at the point of entry. But then you still need a fan to blow the heat throughout the home. And with no air intake, distribution through the home would be limited, unless the home has heating/AC ducting.

So perhaps more than one system is called for. A small water-based system for warming the bathroom floor, while an air system heats the home overall. That would still leave an issue of underfloor access to the bathroom. But that is a heck of a lot less daunting than trying to access the crawlspace in each separate room. 

If Jim can draw up a floor plan, that would go a long way towards identifying a solution.

Greg in MN
stmbtwle

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Reply with quote  #15 
Hi Greg.

In my installation the holes are drilled just above the floor, from the inside, and everything is in the living space (I'm on a slab); that's what I had planned for Jim.  My storage is also outside, not the best place for it but the only place I have available (see the link).  My thought for Jim was to build the system "quick and dirty" with NO storage, and see how it worked. The storage can be installed later, if needed, with a minimum of hassle.

My idea re the water lines inside the house was to run the lines around the perimeter of the rooms, like a baseboard heater. When one came to a doorway one could either go through the doorway into the next room or double back.  

For heating other rooms one could:
A: Go through the doorways
B: Drill through the interior wall
C: Go OVER the wall through the attic.
D: Come in from outside either through the window or the wall. 
E: Combination of the above.  

We already know the three bedrooms and bath are on the south wall.  They probably aren't occupied during the day when they might be hot, but will be comfortable at night.  On the north side would be the living area and kitchen, comfortable in the daytime and possibly cold at night. Seems like a logical layout.

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Solar is like the wind. It may be free, but putting it to work isn't!
Willie, Tampa Bay
Jim

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Reply with quote  #16 
Here is a rough floor plan. Not exactly to scale. The south wall actually faces about 20 degrees east of south.  

IMG_20170524_105818604.jpg 


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Jim in Chihuahua, Mexico
Jim

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Reply with quote  #17 
This is an aerial shot. There are a few trees to the south but I watched last winter and they don't shade the house at all except for the pine tree at the southwest corner. It is mostly dead now and only the skeletal shadows of the topmost branches move across the wall in the afternoon. 

Screen Shot 2017-05-24 at 11.22.33 AM.png 


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Jim in Chihuahua, Mexico
stmbtwle

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Reply with quote  #18 
Hi Jim,
That's pretty much what I had in my "mind's eye", Thanks!

So what is YOUR opinion about going back to your original plan of a water-based system? It is after all YOUR home.


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Solar is like the wind. It may be free, but putting it to work isn't!
Willie, Tampa Bay
Jim

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Reply with quote  #19 
This whole project started several months ago when I sat down to look over our monthly living costs. Our biggest expense is propane for the water heater and the stove. (Got plans for a solar cooker "cooking" in the back of my brain as well.) The next biggest expense was firewood during the winter months. I am hoping to bit by bit, whittle away at the monthly expenses as funds are available. A solar water heating system seemed like the most obvious first thing to tackle, so I bought the used panels, pump, and drums with the idea of also using the heat to supplement the wood stove during the winter, hopefully reducing or eliminating the firewood costs. I got stuck in trying to figure out how to distribute the heat from my tank to the house. The only thing I could visualize was a radiator and fan hanging from the ceiling. Ugly and noisy [frown] .

But after reading about the simplicity and performance of some of the air heating collectors you guys have built, I thought that might be a less complicated way to go. If all goes according to plan, the house will eventually have concrete floors throughout with radiant heat. But it will take quite a while. The reason I'm trying to get it all figured out now is because I am about ready to start the installation of the hot water system and some of the design will be affected by whether I use it for space heat as well.  Any supplementary system I put in will be phased out as we gradually shift all the rooms to radiant floor heat. 

To me, the collectors hanging on the side of the house blowing through the windows looks like a non-intrusive, easily reversible way to supplement the wood stove. Eventually, I will need the capacity of a bigger storage system, but at the moment, I could keep it smaller and use the air system in the rooms that don't have heated floors yet. I had just never considered air before because I assumed you would need a monstrous panel to put out enough heat to be practical. 

You mentioned the attic - there is an area where improvements could be made. The ceiling is lath and plaster with 2X10 joists, then 3/4" boards with a 4" layer of earth on top. I would like to blow in about 16" of fiberglass on top, but I do not know yet if anything like that is available here. There is also a thick layer of bat guano on top of the dirt up there, so I am most definitely not interested in drawing any hot air from the attic into the living space. The attic is now sealed up enough that the bats no longer live there, but the smell is still bad enough that I wear a mask whenever I go up there. 

At the moment, I think I prefer the idea of the air heat. The wood stove will still be there if it doesn't produce enough. It seems like anything temporary that I put in to use the hot water would be less than satisfactory. There are a half dozen other smaller houses on the ranch that could use the heaters as they get phased out of the big house. Summer storage for the collectors is not a problem - nearly 2 acres of storage available in an old apple refrigeration building here at the ranch. And, also, I enjoy the challenge of thinking through, designing, and building something like that. Keeps the brain from rusting out!

I'll have to keep thinking about blowing heat into the crawl space. The idea is very attractive but the doing seems a little complicated. Maybe I could cut a hole in the floor of bedroom #3. it is in bad shape and is next in line for a concrete floor upgrade. 

I do like the idea behind the passive heater that Rick pointed out. Electric cost here jumps from 4 to 15 cents per kwh after the first 130 khw a month. But I question whether those heaters would put out enough to be worth building when compared to an actively circulated model. I also have plans for some grid-tied electric panels sometime in the future, so that would offset the electricity usage of the blower. 

Brainwave that occurred to me just now - would it be possible to drop the collectors to the vertical position in the summer, remove the glazing and the air heating "cartridge", and put in an evaporative cooling "cartridge"? The blower looks like the most expensive part of the project, so you could get year-round use out of it that way. 

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Jim in Chihuahua, Mexico
Jim

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Reply with quote  #20 
Here are the hot water panels I am working on. I bought them on Craigslist from a plumbing company in Las Cruces, NM. They had taken them off an apartment building and were anxious to get rid of them. 

IMG_20170524_115349320.jpg

These are two 4x8 units built by Novan. They seem like a very sturdy well built panel. The rubber seal on the glazing had gotten twisted on both of them, allowing dust and water to enter the interior. All I had to do to these is open them up, clean the absorber with a wet rag, wash the glass on both sides, and put them in the sun to dry out before sealing up the glazing again. I just need to solder a copper union fitting on the manifold ends, then these are ready to install. The paint on the absorber looked to be in good shape yet, so I left it alone. 

IMG_20170524_115245034.jpg   
The 4x10 unit is a Heliodyne. It is definitely built a bit more flimsy than the others. They depend too much on the glazing frame to stiffen everything up. The plumbers kinked the risers on this one when they de-installed it, so the guts are currently at a radiator shop to get repaired and brazed back together. The sides had flexed enough that the glass had come completely loose from the frame along one side. The absorber and underside of the glass were quite heavily caked with dirt. When I wiped down the absorber with a wet rag, most of the paint came off as well. I will need to repaint it when it comes back from the radiator shop. 

I am not quite sure how I will mount these guys on the roof. I am planning a drainback system so they will be as close to the peak as possible. The planned location for the storage drums is in the attic on a wood-framed platform that I will build on top of the hallway walls. The 15" adobe walls should be easily strong enough to handle the weight. They are not carrying any roof load and extend all the way down to the stone foundation. This location will give me about 36" drop between the bottom of the collectors and the top of the drums. What I am not sure about is whether I want to put them flat against the 20 degree slope of the roof or to build a frame to raise the top for a steeper angle.


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Jim in Chihuahua, Mexico
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