An airlock improves energy efficiency on the straw bale shelter.

An airlock improves energy efficiency on the straw bale shelter.


Suggestions from one of our readers on how to make the straw bale emergency shelter more comfortable in cold climates. This amazing shelter can be built in just a few hours.

“I just found your website as I am on a quest to ‘put a roof over my head’ as cheaply as possible. I have just started to browse through your website and I read a comment from a lady who had ‘survived’ very cold weather and snow in the Emergency Straw Bale shelter, so I looked and found the post about this shelter.

Double pane windows help keep the cold out.

Double pane windows help keep the cold out.


Please excuse what may seem like arrogance on my part (I assure you it is not) but I would like to give you three suggestions that might be helpful to people who intend to use a shelter like this one during cold weather. I have attached three sketches which I hope as self-explanatory. Please have a look at the attached. If you think there is any merit in them please feel free to pass them on to anyone who might be interested. Or put them (but not my name please) on the website if you wish.
Improvised insulated windows made from low cost materials.

Improvised insulated windows made from low cost materials.


The website is a mine of information by the way. I’m enjoying not just the new things I am learning but also the idea that, if others have managed to build a simple sturdy warm and functional home for themselves without a mortgage, then perhaps I can too.”
Regards,
Anonymous

Owen: We’ve covered airlocks in a separate blog post, but it’s good to show how they can be applied in this situation.

Here’s the straw bale shelter video.

I can assure you many thousands or tens of thousands of people have built themselves low cost housing like you are seeking. The main obstacle is obtaining documentation about these projects. Most people (especially those who are circumventing codes) do not want to publicize their projects or otherwise attract unwanted attention. That leaves us with the relatively few that people send us info and examples we find on the Internet. So again we ask readers to please take good quality photos and send us 1-3 paragraphs about your project.


Comments

Straw Bale Emergency Shelter Cold Weather Upgrades — 13 Comments

  1. This is an excellent post.

    I hope this discussion with be repeated and emphasised to educate people to the maximum degree to a level of importance appropriate for the impact this topic has on structures.

    Windows are a very underdeveloped arena for maximizing performance while minimizing costs in any structure, but especially in the natural building field.

    What is almost never appreciated is how easy it is for anyone with a modest mount of carpentry skill to build their own state of the art ultra high performance windows. They can be build just as high quality and performance as the best commercially manufactured windows, but only if an individual does appropriate research. They also can be built for pennies on the dollar compared to commercially built windows.

    Many natural builders promote the use of salvaged materials. I myself promote the use of salvage frequently, however, most salvaged windows if used without proper repair is an exercise in futility. Most old windows leak and perform poorly when maintained incorrectly. I would even go so far as to say that if you live in a climate with modest extremes in temperature, that using salvaged windows without DIY UPGRADING them to the highest performance, you are not building with respect to natural resources. In fact, you are wasting natural resources and wasting money at the same time. This is just my opinion, but simple engineering calculations will back up my position.

    I make this statement for a variety of reasons.
    1. All windows are effectively a big hole in the thermal envelope of a building. Even slight gains in performance of the windows translates into massive saved energy, natural resources, and big money over the lifecycle of even the most simple basic structures.

    2. The high tech performance characteristics of the most expensive commercially built windows IS ACCESSIBLE to the DIY builder that is willing to take the time to build or modify their windows with care, and then install them correctly to assure that they are water tight, completely sealed, and installed correctly.

    3. Building custom or modifying salvaged windows is not as complicated as it appears. It is not as costly as many believe. It can be done with modest tools and some basic knowledge.

    I am going to explain one way how to do this in a follow up comment.

    • Okay… enough preaching on my soapbox. Time to get down to practical matters.

      How can a DIY builder custom build or modify salvaged windows to achieve performance similar to the best commercially made windows?

      Here is ONE METHOD I have used personally for a client. Keep in mind that there is always more than one way to do something. For this example, I modified the existing single pane windows with leaky aluminum track storm windows in an existing structure. This is a very common type of window that is often free and easy to find for salvage.

      1. Completely strip all the old paint off the old window. remove all the old putty, remove all the glass. (cost=nothing time spent)

      2. Replace/repair any broken wooden parts or cracked/broken glass. Replace using glass cut from the crappy leaky aluminum triple track storm windows. (cost=nothing but the time spent)

      3. Prime/paint all the wood parts, including all the window muntins. Use a high gloss paint because it will seal the best. Do not skip this step. The wood must be completely sealed. (cost=primer/paint [pennies to maybe a max of a $1 per window for expensive paint], and the time spent)

      4. For each pane of glass, create at least two very thin wooden frames that are the exact dimension of the glass. This will allow you to create a high performance triple pane window. If you desire an even higher performance quadruple pane windows, add one more thin frame for each pane of glass. Prime and paint each of these thin wood frames to match the window muntins. (cost=nothing but time spent if using salvaged wood cut into very thin strips.)

      5. For each thin frame (except one per pane of glass… more on that later) stretch a sheet of thin MYLAR over the frame and seal it with a fine layer of thin silicone to the thin wooden frame. Visqueen can work for a couple of years as suggested in this blog post, but it breaks down when exposed to ultraviolet light. Mylar is FAR SUPERIOR and worth the extra cost.

      Gary Reysa at BuildItSolar.com has a lot of great information about the use of Mylar to create storm windows. He has performed a multitude of excellent scientific experiments. I refer you to Gary’s outstanding work to justify the use of Mylar, as well as a more detailed explanation how to attach mylar to a thin frame with silicone. He has many pages of information. The web page linked below is just one example. I encourage you to search his website for more information. He truly has an excellent library of knowledge available to anyone just at your fingertips.

      http://www.builditsolar.com/Projects/Conservation/MylarStorms.htm

      Keep in mind the total lifecycle costs (both in money and natural resources) of the windows and the structure. Cutting corners by using a material that won’t last a period of time that compares in magnitude to the lifecycle of the structure is foolish and wasteful. Wasteful in money as well as natural resources. Do a quality job the first time and it should easily last the rest of your life. (cost=the price of the mylar (variable by the size of the window, $15-$20 per window is a reasonable “guesstimate” for average sized windows, and time spent)

      6. Cut an extra pane of glass for each pane exactly the same size as the original. Use glass from salvaged aluminum storm windows. (cost=time spent)

      6a. (OPTIONAL) Apply a low E tinting film to on of the panes of glass if low E performance is desired. These films are available at hardware stores and even shaded tintings are available at auto parts stores if you prefer the darker tints. (cost=price of your chosen film, time spent)

      7. Seal the extra pane of glass to the unmylared thin wood frame with silicone. (cost=silicone[trivial], and time spent)

      8. Allow all of the silicone to dry/cure on all parts for several days. Do not skip this step or the final assembled windows may fog on the inside later due to condensation of the outgassing of the silicone caulk. (cost=time waiting)

      IMPORTANT. STEPS 9-12 ARE BEST PERFORMED ON A LOW HUMIDITY DAY OR IN A LOW HUMIDITY ENVIRONMENT.

      9. Assemble a sandwich of glass and mylar frames. The two glass panes should be the bread of the sandwich on the inside and the outside. The mylar frame(s) should be on the inside like the meat (and cheese) of the sandwich. Make certain that the thin wood frames keep the mylar sheets suspended and separated and do not allow the mylar to make contact with either pane of glass. If the original window used tempered glass, put the tempered glass on the inside of the window for maximum safety to occupants.(cost=time spent)

      10. Bake free salvaged “DO NOT EAT” silica gel packets in the oven for a couple of hours at a very low temperature setting. around 200-225deg F. This will dehydrate them from whatever water vapor they have absorbed.

      11. Place some granules of silica gel inside each air gap between each layer of glass and mylar. The amount varies with the size of a window. I typically use about

      12. Seal the entire perimeter of the sandwich. Silicone will work okay, but epoxy performs drastically better. I know epoxy is a nasty substance. It smells bad. It outgasses terribly. It’s probably not the best stuff for the environment. I usually avoid the stuff whenever possible. This is one application where I believe the benefits far exceed the detriments. Using epoxy will allow this sandwich to last for decades. Well… they will last for decades if you or some kids don’t throw a baseball through the window, but what is the point of having great windows if you can’t have fun watching kids play ball outside. I say let the kids (of all ages) have their fun. You built your windows so you will know how to repair them very cheaply if the accidental ball breaks one pane. Enjoy life. Play ball. Don’t stress over it. Deal with accidental breakage when it happens with a smile and gentle instruction on how best to avoid future accidents while still having fun. We all were a kid once. Some of us never completely grow up. (cost=sealant perhaps as much as $1 per window, time spent)

      13. Let the perimeter sealant dry/cure for at least overnight.

      Here comes the BEST part. The science proven way to supercharge the performance of your windows to make the perform just as well as high tech commercially built units. You can opt to skip the next few steps (14-19) and settle for a decently performing window using air as the insulating gas. However, to supercharge your window performance, replacing the air with a better performing gas is worth the extra time and money. It is very easy and cheap to do, especially if you have a lot of windows to do this to.

      14. Use a very small diameter drill bit to drill two tiny holes through the edge sealant into each of the thin wood frame separators at diagonally opposite corners. The drill bit should be just barely big enough to allow a hypodermic needle to squeeze inside the sandwich through the hole.

      15. Attach a hose from a tank of Argon or Krypton gas to the hypodermic needle stuck through the edge of the sandwich into one of the air gaps. Argon gas is the most commonly used high performance window gas. Krypton gas is the absolute best state of the art highest performing window insulating gas used today and is what I recommend if you can get it locally. Both gasses are non toxic and heavier than air. Both gasses are noble gasses that are inert and won’t react chemically with much of anything under normal conditions. (Check your periodic table of the elements and a high school chemistry book if you don’t believe me.) They are very safe to work with. No special respirators required.

      Both gasses can be purchased at a WELDING SUPPLY STORE. Their smallest tank will more than fill your needs with plenty to spare. In fact, if you have a friend that is a welder, he may already have those gasses and will be willing to help you so that you don’t even have to buy the tank. Check your Yellow Pages. Look under welding supply. One common supplier in the U.S. is “Airgas”. (Not intended as an endorsement of this particular company, but it is probably the most common name and will be easy for most people to find in their area.)

      16. Hold the sandwich vertically such that the needle is lowest to the ground and the diagonally opposite corner with the open hole is at the highest point from the ground. Krypton and Argon gasses are both heavier than air. They will fill the bottom of each cavity first expelling the air from each cavity out through the top air vent.

      17. Very very slowly open the tank valve and gradually fill each airgap with Argon or Krypton gas. The slower you fill the better. You don’t want to blow the sandwich apart. Be very gentle. Practice opening and closing the valve a couple of times without the needle inserted to be certain you can open and close the valve just slightly to allow a tiny trickle of gas to flow. Don’t ruin all your hard work building your window sandwich by blasting it apart with a compressed gas at the last steps.

      18. Once a gap is filled with Argon or Krypton, turn off the tank of gas and seal the vent hole with the same sealant you used all around the perimeter of your sandwich. Then remove the hypodermic needle from the bottom of that gap and fill that hole with sealant.

      19. Repeat steps 14-18 for each airgap on every window pane sandwich.

      20. Use silicone (not epoxy) to seal/glue each sandwich window pane into the window frame.

      Finally, it is important that you not neglect the other operational seals of the window. It won’t matter how high performing your window glass is if it leaks around each sash and has crappy weatherstripping. Pay attention to the details. In fact, air sealing and weather stripping a window is more important than high performing multipane glass. Invest your money and time sealing the operating mechanical parts of a window before attempting turning any window into an insulating window. A well sealed single pane of glass is better performing than a leaky window with 5 layers of Krypton filled high tech insulated glazing. Do the basics first. Walk before you run.

      I’ve tried to explain the process as best I can. Hopefully this will help someone figure it out. Most any reasonably capable carpenter should be able to build something like this without much difficulty.

      • Everything sounds good except I wonder how long improvised windows like this would hold argon or krypton.

        • The gas will last nearly indefinitely if sealed with Epoxy.

          The atoms of these gasses are very large. Much larger than the Nitrogen and Oxygen atoms that make up the majority of typical air. That means that Argon, and especially Krypton will have a much more difficult time escaping.

          It’s the glass and the epoxy that are holding the gas inside. Not the wood frames.

          The process I described is effectively the same technique commercial manufacturers use. All I did when I did this myself was adapt the commercial process to DIY tools and materials.

          Here is a “How It’s Made” video describing a dual pane Argon filled thermal window construction. This one uses Polyurethane glue as a sealant. It was a video similar to this one that inspired me to try to do it myself. I really wasn’t very difficult. It took some time, but not too much longer than simple refurbishing of any salvaged wood window.

          http://www.youtube.com/watch?v=gXqNi8KB9ws

          Ugh… now that I watch that video, I realize that I left out the important step of cleaning the glass thoroughly before assembling the sandwiches. That should be common sense, but I still should have included it at the proper place.

          Oh well.

          The point of that video is that the thermal pane is nearly exactly the same process that any DIY builder can do themselves.

          Salvaged glass (triple track aluminum storm windows are so plentiful in salvage that it’s rediculous. I always grab them when I see them by dumpsters so I don’t have to pay for glass, and then I toss the aluminum in the aluminum recycle bin in my shop. Then I get paid for the aluminum at the metal recycling yard in the big city whenever I make that trip.) I never pay for plate glass for any project anymore.

          Salvaged wood is easy to find for free.

          Most of the cost is the Mylar, the epoxy (or the polyurethane glue), and the insulating gas, and most of the cost of the gas is the initial purchase of the tank which can get refilled.

          Yes… the work can be tedious, but it’s a great project to work on in your shop during the bad weather winter months. Have them ready for the next construction season. Of course, that requires that you know that far in advance what windows you’ll be using the next season.

          • Consider making a video to demonstrate the process. It would probably be very popular.

          • Popular? HA! Get real.

            Nobody wants to see an old fart like me on YouTube unless he’s getting his pants snagged on a loose bolt on an escalator and ends up on the 2nd floor of the mall half naked and then some woman sees my state of half dress, gets offended, and hits me with her 15lb handbag knocking me back down the up escalator.

          • I meant the topic would be popular. You can demonstrate the process without showing your face if you want. Now, I realize many people are too busy to make their own modified insulated windows, and I realize many aren’t up to the task or understand the long term benefits. But I suspect there are quite a few (many thousands) who would watch. For what it’s worth, I prefer short videos that show the key points only. I suspect there are many others who prefer not to slog through long videos. The main point is it’s easier for some people to learn by watching than just reading about something.

          • Thanks Owen,

            I got your point. I just don’t give two hoots about popularity.

            I’m not saying I won’t try a video, but I’m not convinced it will be all that popular. The thing is, popularity wouldn’t really matter all that much to me. It’s one of those things that I would do to try to help a few people the way that some of my mentors helped me learn to do things when I was younger.

            A few hundred views is about what I would expect, and that’s fine with me if those that do view the video learn something from it and some of those are able to take advantage of the knowledge and put it to use for themselves. Heck, somebody will probably figure out a way to do it better than me, and if they do, I want to hear about what they did so I can steal their ideas too.

            The thing is, a video wouldn’t really include any information beyond what I’ve already included in these comments. It would simply make the information easier to understand. That has value too, I guess.

            The next time I modify a window to turn it into a thermal window, I may try to make a video, but only if I’m not under a time crunch. I’m not exactly a video expert. It takes me a while to do those types of things. It will easily double the length of time I need to complete the project if not triple. If I have a deadline to meet, then the video will get postponed to another time.

            I do know that my client for my first set of windows has been extremely happy with his windows. He has a very nice home that is over 150 years old. He wanted to keep the authenticity of the old windows, but he also wanted better efficiency without the gawd awful ugly triple track aluminum storm windows the previous owners had slapped on. They weren’t even good ones. Crappy ones probably made in the 1970’s during the oil crisis. Those old storms made this beautiful old house look like a trashy rundown rental.

            In all honesty, the most difficult part of working on those old windows, aside from removing them from the house without destroying them, was dealing with all the old lead paint. It was really nasty getting that stuff off in a safe manner. We never used to worry about those things when I was starting out. I understand the risks and respect the need to avoid spreading contamination all around. It sure wasn’t much fun, though. Usually I enjoy my work a lot, but stripping all that old paint still gives me shudders today just thinking about it. 8 layers. It was like trying to remove petrified tar from an asphalt driveway while working inside an uncomfortable plastic suit.

            They were beautifully built windows by the original craftsman. I’d like to think that if that old craftsman were alive today he would have appreciated my efforts. Most people don’t realize that they have been modified to the extent that they have been. I’m rather proud of that. Only people that do this kind of work for a living tend to notice that the windows have been upgraded. When people don’t notice that I did anything to an old window like that, I think I’ve done my best work. It’s like I’m invisible.

            I don’t know when I’ll get another project where I’m doing that to a window, but I have been getting several local people asking questions about how much I would charge to do the same thing to their windows, so it’s probably only a matter of time before I get another job similar to that.

            Meanwhile, this old fart just tries to keep busy fixin’ stuff and tries to keep his pants up when on the escalator.

          • By “being popular” I mean quite a few people would likely watch the video. This has nothing to do with you “being popular”. Word of mouth advertising is already starting without any extra effort on your part.

            Suggestions/comments:
            – a picture is worth 1,000 words
            – hire someone to do the video (high school kid, neighbor, relative…)
            – keep it short and to the point
            – even very simple videos on my Earthbag Natural Building YouTube channel get 5,000 – 15,000 hits

    • Yes, recycled windows can be a big money loser due to energy loss. And yes, most heat loss is through windows and doors (and roofs) and so it pays to focus on these areas to cut energy costs.

  2. The airlock is particularly easy to build and effective. The same basic idea can also be used on nicer straw bale homes, earthbag homes, etc.

    • I don’t mean to pile on the comments for this blog post, but I really appreciate the principles being promoted. They make a great deal of sense.

      I would like to add that building an airlock into many (most?) earthbag structures would be very easy. When buttresses are used for the door openings, they naturally lend themselves to two of the walls for the airlock. Why not finish the job? It just makes a great deal of sense to build those buttresses out and make the airlock. This can be a very practical useful space in any climate as a mudroom. It’s very nice to have that entryroom for storing coats, umbrellas and mucky shoes. Such a room does wonders to help keep the living space inside much cleaner and more comfortable.

      I am a big fan of these spaces. They used to be very common, but “new code approved” structures seem to have mostly abandoned them, to the detriment of every structure that doesn’t have a mudroom/airlock. Now all the muck gets tracked into the house and parents are stressed out fussing at kids for bringing all the mess inside with them.

      Bring back the airlock/mudroom and bring peace back to family life and reduce parental stress!!! Can we get a more valuable payback than a more peaceful family life?

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