One of the advantages of building a tiny house or small house is there is seemingly more time and more interest in building such a house with as little heat/air loss as possible. Through photos we have seen far more fuss and concern over insulation, joint tightness, ceiling framing and “sandwiching”, and overall attention to temperature detail then perhaps in larger sticks ‘n bricks. No matter how much care is given to the topic there is still a chance of heat/air loss/gain and that is typically found in the window areas. And while windows give our little homes light, warmth, ventilation, and even ambiance, they also play havoc with our energy efficiency. One way to reduce such energy costs is two-fold. The first method is to install energy-efficient windows or retro-fit your home with energy-efficient windows. The other method is a more simple and cost-effective one and also a more historical option.
The window quilt is a dateless tradition in heat retention and is a simple enough method of reducing up to 80% heat loss through window glass. In fact, in our first winter in the tiny house we realized that despite our ENERGY STAR windows with a significant rating the sub-freezing temperatures outside were no match for the glass or gas pocket within. We needed something more. That is when I remembered seeing a documentary – This Far By Faith – on PBS that covered The Quakers during the 17th century. Having settled in Pennsylvania they were forced to endure some rather unfortunate weather scenarios and turned to their own resourcefulness to solve the problem. Many of the small homes would use standard quilts made by the women to cover up windows and doors thereby stopping any unwanted drafts. So what exactly is the window quilt other than a blanket hung upright?
The Window Quilt
In the most simple of terms the window quilt is just that. It is a blanket (or quilt) that is hung on the inside of a window to reduce heat transfer through your tiny house windows. And while wall cavities vary in their insulating capacity (ranging from R12 to R40), windows, and especially older, aluminum ones, can be as ineffective as R2. In fact, the average window at a big box store is still only R4 to about R7 with the cost rising with each R-value. So a window quilt with its topping, filling (or batting), and backing can easily add another R8 to R10 insulating property to give your windows a total of (optimistically speaking) R10 – R12 which is pretty comfortable when considering the use of a proper indoor heating system as well. Adding another R5 (the quilt) is comparable to adding 1″ of styrofoam insulation.
How Do We Lose Heat Though
Very quickly, there are 3 ways windows lose heat from your house:
- Conduction. This is the transfer of heat energy by contact. Warm interior > window glass > cold exterior.
- Convection. Heat loss caused by moving air.
- Radiance. Loss of infrared energy using the windows as light energy.
A window quilt addresses all three loss methods by creating another layer between the interior air and the exterior air.
Conduction is the simple transfer of heat energy by contact from the warm air in the room, to the glass, to the cold air outside. (In the case of double glazed and triple glazed units, conduction losses are slowed by creating more layers to be crossed, including insulating layers of air or inert gas.) Convection is the loss caused by moving air. Radiance is the loss of infrared energy simply transiting the window barrier as light energy, to which the windows are fairly transparent. The quilt covering our window addresses all three heat-loss modes. It creates an additional boundary layer between the warm air in the room and the cold air outside – in fact, 4 layers of boundary, to reduce conduction loss. By hanging against the window frame, it prevents air from flowing from the room to the window surface, reducing convection loss. Finally, by including a radiant barrier within the quilt, it reduces radiant heat loss.
What we found was that hanging quilts (which was archaic in our approach….read: duct tape and clothespins) once the sun started dipping down everyday we would maintain our interior temperature more effectively while staving off the chill that came with nighttime. We would reverse the process in the morning and allow the sun to heat the house and do its job. And because we used quilts we really liked and because winter has that certain “feeling” our tiny house really was not just warm but also quite cozy.
What about you? Have you ever used window quilts or are they something you may see a need for now? Do you remember anyone in your family historically using them?
By Andrew M. Odom for the [Tiny House Blog]
I’ve thought about using quilts or blankets over my windows and walls. I live in a 1973 Stardust cruiser that has 1 inch plywood walls. I haven’t proceeded with that yet. However, over my single pane aluminum windows I have placed opaque floor underlayment. It shows white from the outside and lets light in. Looks like frosted glass. And I can tell it helps somewhat with heat retention.
Quite cool (or warm). We’re also using window quilts on our small, but not tiny energy efficient home. My wife is a watercolor artist so we had custom material made using her art,
One thing we read was that the quilts should be against the window frame on all four sides, but especially the top and bottom. Otherwise the cool air against the window and the warm air rising in the room creates a chimney effect that passes that warm air through the openings, cooling it before ejecting it back into the room.
Thanks!
I made window quilts for our old Victorian house back int he 70s! They’re gone now, but they did work great…
If you quilt them yourself, you could applique/quilt the scene outside that window…for southerners, you could have a white Christmas…or you could have a “Starry Night,” French cafe scene, beach front, and, for children (and me), an enchanted forest, filled with elves and sprites…or a Dr Seuss village…the prospects are endless…
Forwarding this to my friend who loves quilting 🙂
this is great, thank you! what is the radiant barrier you use in the quilt?
Clued together 2 rigid insulation pc’s to get R-10. Affixed quilt fabric to one side, then reflective barrier for summer on the other side. Have 2 finished pc’s of wood that extend 3 inches past each side. When cold enough or too much direct sun just put in window and let the wood slide into bracket that holds it against the window.
What are you using for a radiant barrier in your window quilts?
Look below for my comment about the type of batting quilter’s use for window quilts. Can be purchased at any fabric store. Hope that helps.
Topstitch
•Warm Insul-Bright by the Warm Company Batting for Quilts
Insul~Bright consists of hollow, polyester fibers needlepunched through a nonwoven substrate and through a reflective metalized poly film. The needled material is breathable and won’t break down with washing. The hollow fibers resist conduction while the reflective metalized poly film resists radiant energy. The energy, hot or cold, is reflected back to its source. •Needlepunched Insulated Lining
•Reflects Heat or Cold Back to the Source
•No Pre-wash Necessary
•Machine Wash and Dry
•Made in the U.S.A.
I’ve made many a window quilt using InsulBright but after it made a giant leap up in price a few years ago I’ve successfully used a psuedo-version composed of one or more layers of washed wool (old blankets) and a layer of mylar film (“emergency blanket” type works well) along with a layer of product called Thinsulate if I need a really heavy-duty quilt. I don’t actually quilt the layers as the compressed quilting line works against the insulation value; I simply align the pieces well and secure all at the edges. For large house windows this is insufficient stabilization but for campers and tiny houses it seems to be working fine. I have made some as Roman Shades, thereby requiring stitching at intervals for the drawing cords and on those I don’t notice cold spots.
Sarah
I have read that spraying your window with water then attaching some bubble packing (the kind used by UPS, FedEx, U-Haul) will also aid in keeping your residence a bit warmer. It is a cheap, quick fix until something more permanent is done.
I have constructed insulated curtains for my RV using these materials cut to fit the inside frame face & mounted on outside of hanger sticks (top & bottom) that slip into brackets mounted on wall in a position that will hold the curtain against the window frame.
This construction will absorb condensation easily and dry easily without mold/mildew problems.
Reflectix
reflective coated bubble insulation
http://www.homedepot.com/p/Reflectix-4-ft-x-25-ft-Double-Reflective-Insulation-BP48025/100052556
Polyester Fabrics
http://www.walmart.com/search/?query=polyester%20fabrics
1/2″ High Loft Batting
http://www.walmart.com/ip/Morning-Glory-High-Loft-Batting-4-pack-110-x-110/19397508
You could use “hollowfill” sleeping bag material as an easier build material but usually contains cotton which requires drying to prevent damage.
Growing up in houses built in the 1800’s , we tended to focus on warming the body more than the house. These houses were not insulated, and had Windows that shook , every time the wind blue, and had gaps around the doors. The ceilings were twelve feet high, making it hard to to heat the house. I remember rolling up towel, putting them up against the bottom of the door. That was the extent of the efforts made to help block the cold out. Hanging quilts sounds like it would help. If I ever move to a really cold place, I’ll do that. Living in CA, for the last thirty odd years, I haven’t needed to heat the entire house, once. Just the bathrooms, for an hour in the morning, and an hour at night.
Wow, that can be really useful information. Thank you so much for that. : )
We have a tiny house with large windows – too large for a heavy quilt. I’ve found an ideal solution. (Prior to this I used large bubble wrap which functioned fairly well but insulated only half as much, and looked stupid from the street.)
I made interior storm windows from the metal frames and the plastic cording that are normally used to make screen windows. Rather than screen, plastic roll sheeting is stretched taut in the frames, so it’s like having slightly blurry glass. From the street you would never know it’s there.
For my windows I had to put in a center support made of the same metal. Because I have no wood framing of any kind around my stucco windows, I’ve had to use the solution of holding them in place with the kind of putty used to seal air gaps. I only use it in the corners. Even though the seal is not complete around the sides, the air flow is minimal and offset by the amazing insulating properties of the plastic sheeting.
The bottom line is that I was able to save $700 the first winter I had them, and didn’t get them in until January. My house walls are much, much colder to the touch than the plastic storm windows. I keep wondering how I could wrap the whole house in plastic for the winter. Summer too, for that matter. When the windows are closed in the summer during the AC season, they work in reverse.
When I lived in the Yukon I put up shrinkable window film inside every winter and that combined with thick curtains made a big difference. Before that we used to use heavy plastic stapled on the outside but that always caused the windows to frost up as the escaping warm air hit the plastic. Using plastic inside stopped the air leaks completely and definitely made a good tight air space to slow down heat transfer.
When I spend time in the Boler trailer in cooler weather I wrap clear plastic bags around the screen inserts and it keeps drafts from the jalousie windows at bay for a much warmer interior.
Condensation can be a big issue behind a fabric window covering.
I’ve done this! While we don’t live in an official tiny home, our rented house is rather small, less than 1000 square feet for a family of five (with five pets). The home is old, and drafty, and I took a quilt I got for ten dollars at a thrift store and covered the enormous windows in our living room. The queen-sized quilt was barely big enough, but it came out beautifully and our heating bill went down by about 20%!
http://allureofhearthandhome.blogspot.com/2013/12/i-wonder-how-much-i-will-save-now-on.html
i purpose make quilted roman blinds. same mechanism as a regular roman blind but as thick (ie 3 layers) as a patchwork quilt. They work a treat. Initially I made them to keep the heat out as we regularly have temperatures over 40 degrees C. But they work just was well at keeping cold out and heat in in winter.
I have a large piece of mill felt given to be used as a blanket- grandpa used to work in a paper mill. Rather than just get rid of the heavy thing, I added some nails above a large drafty window in the kids room that I hold the mill felt up with. Each year we get to use the mill felt, think about Grandpa and keep us all warm. I may think about adding the straps though to allow more light in during the day.
Did this one winter in Montana when it went to -30 for three weeks. I heated exclusively with wood, and had 3 floors to heat. My many windows helped during sunny days, but were a huge drain at night. I put blankets over all my windows at night-the north side ones never came down-but I noticed a difference immediately!