I know it sounds like an odd question. We tend to think of using solar design for houses, not clothes. I’ll explain.

If you know it’s a cold day, do you think about what you’re going to wear? Of course you do. You might wear several layers. The layering forms more tiny air spaces around you and increases the insulating effectiveness of your clothing. You might pick out dark colors. Even if you don’t think of this as “passive solar dressing,” it is. dark colors absorb the radiant energy from the sun better than light colors. I’m sure when you’re outside on a cold, but sunny day, you walk on the sunny side of the street to stay warmer than you’d be on the shaded side. Ah! Passive solar principles, again. It’s nothing more than proper insulation and receiving the free energy benefit from the sun.

Insulation is important, so let’s not forget your hat. We always hear that we lose the most heat through our heads. Your house loses the most heat through the roof. Heat moves upward as hot air rises. So wearing a warm hat is like putting good insulation in your attic and roof. It’s the place where the investment produces the most benefit.

We do the same thing in the summer, using passive solar principles to stay cooler. Don’t you choose light colored clothes? Light colors reflect the sun’s radiant energy. You’ll stay cooler. A light colored roof in a hot climate will keep your house cooler, too. Don’t you pick clothing that breathes so you’ll stay “ventilated?” Natural ventilation in your attic will reduce your air conditioning expense. It won’t have to work as hard. With the right ventilation in many climates, air conditioning may not be essential, even on the hottest days. On a hot summer day, you might also wear a hat with a big brim. That’s like having a house with proper overhangs to shade the walls and keep the house cooler. The shading keeps you cooler whether it’s a hat or a roof.

I wrote another blog post last winter about using solar energy to help clear my driveway of snow.  It’s rare to get much snow where we live in North Carolina. But it happens from time to time. Hey, if Mother Nature is giving us free energy, we might as well use it. It’s simply a matter of understanding how to use it.

If you would like to read more articles about house and home design, please visit my other website, www.about-home-design.com.

Metal roofs, now often referred to as “cool roofs,” can act like your light colored, open weave shirt and keep your house cooler in hot weather. They do this “passively”, that is they use no electricity in the process. Here’s why they work. In an article posted at Classic Metal Roofing Systems website, they list four energy benefits you’ll get with a metal roof.

1. Thermal Mass. Mass is the “weight” of a material. Stone has more mass than wood because a chunk of stone weighs a lot more than a the same-sized chunk of wood. Heavy asphalt roofs have a lot more mass than metal roofs. The higher the mass, the more heat a material can absorb. Although metal can get quite hot to the touch, it does not store heat in its mass and it will give up it’s heat more quickly soon as the sun goes down, or behind a cloud, or even when a breeze blows. So just like your open weave shirt, the material will cool down easily. Aluminum is even better than steel in this regard.

2. Color. Just like your light colored shirt, a light colored roof will absorb less radiant heat. I wrote a blog post about how I use passive solar principles to help clear snow and ice from my driveway. And color was the key. Here’s a link to that article, if you’re interested: http://www.designingyourperfecthouse.com/blog/2009/01/passive-solar-design-on-my-driveway/

3. Reflective Pigment. In the Classic Metal Roof Systems article, they say “Many dark-colored metal roofs now have reflective pigments so that good reflectivity is achieved even in dark colors.” This means that you are not limited to a silver or white roof to enjoy the benefits of an energy efficient, highly-reflective roof.

4. Integral Airspace. Metal roofs do not lay tightly against the roof sheathing. This means that a gap of air is created that insulates the roof sheathing from conducted heat coming from the metal. This airspace acts like a trivet or a pad you might place beneath a hot pan to keep from burning the countertop or table in your kitchen. Asphalt roofs lay tightly against the sheathing and continually conduct heat into your attic or rooms below, adding to your air-conditioning expense.

No matter what roof material you choose, be sure to provide sufficient attic ventilation. Metal roofs do not replace this essential design feature. But metal roofs will keep your attic and house much cooler and keep your air-conditioning electrical costs down significantly.

Metal roofs tend to cost more, initially, than shingle roofs. I’m researching this and looking for ways to control the added costs. I’ll report on this in future posts. If you have any experiences with metal roofing and the energy benefits, please post a comment. I would love to hear from you.

If you would like to read more articles about house and home design, please visit my other website, www.about-home-design.com.

 When the flakes stopped falling, we had about six inches of nice, clean snow on the ground. I put on my tennis shoes (I don’t have boots anymore since I moved south) and found my gloves (they were in my golf bag where I left them following a chillier than usual round a few weeks ago) and set out to clear the snow. I don’t use a snow shovel any more. I’m not sure I still have one. I use my leaf blower, instead. It works surprisingly well. It fluffs up the snow and blows it away almost without a trace. I cleared my sizeable driveway in a little over an hour. The best part is my back doesn’t hurt! 

But here’s the reason I’m writing this post. No sooner had I gotten most of the snow off of the concrete, it started to melt. The air temperature was only twenty seven degrees. The sky was cloudy. But enough solar (radiant) energy still filtered through the clouds, was absorbed by the concrete, and was converted into heat to efficiently melt the dark ice that remained. Here was a perfect example of Passive Solar Design. It’s called “passive” because no mechanical systems are required. It just simply happens. As you might imagine, the portions of my driveway that sit in the shade did not melt. But the totally free energy from the sun did the job for me elsewhere.

 Shouldn’t your house be designed to take advantage of this free energy? I discuss this in more detail in my book, Designing Your Perfect House. If a house is designed properly, the sun’s energy will be kept out in the summer by the use of properly sized roof overhangs. You don’t need expensive solar collectors, photovoltaic panels, pumps, batteries or anything. Simple, thoughtful design will make your house energy efficient. A good architect or residential designer can do this for you. And if you live where you might get snow, be sure your driveway is on the sunny side of the house.

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If you would like to read more articles about house and home design, please visit my other website, www.about-home-design.com.

 
        The second planning consideration involves the mechanical system. A “standard” type of heating and air conditioning system depends on a fairly high velocity of air flow and a fairly small volume of air, which is why you can often hear the system so much when it comes on. This is also why you sometimes feel drafts. A better way is to design a system with large ductwork so you can provide each room with a larger volume of air that is moving more slowly. The comfort of the occupants is greatly increased, the efficiency of operation goes up and the sound levels go down. Of course, to build a system like this requires adequate space for the larger ductwork, so early planning is critical, if you want to avoid conflicts and compromises.

 
        Using multiple HVAC (heating, ventilating, and air conditioning) units that handle separate portions or zones of the house has been the traditional way of designing mechanical systems. What works more efficiently is to have multiple units placed in series, along one main trunk line, that all serve the entire house. What happens is that when the temperatures outside are moderate and the system does not have to work very hard, only one smaller HVAC unit, with a smaller, more efficient compressor, comes on at a time. You are not cycling a big compressor on and off throughout the day. That repeated cycling is very energy inefficient, because the start up of the unit causes a big power draw, and the charging up and cooling down of the unit are simply wasted heating or cooling that slips away from your house unused. On those days when the temperatures are more extreme, the second unit comes on to assist the first, and the proper amount of heating and cooling is provided. The “zoning” of the right amount of air to various portions of the house is achieved by means of automatic dampers that are activated by thermostats throughout the house.

If you would like to read more articles about house and home design, please visit my other website, www.about-home-design.com.

      Bill Hirsch

      www.designingyourperfecthouse.com

      Generally speaking, houses built in cold climates are best built with southern exposure. This simply means that the side of the house side with the most windows should face south. Because southern sun is the easiest to control, properly designed roof overhangs can limit the amount of sunlight that shines into the house (called solar gain) in the warm months when the sun is high in the sky, thus reducing heat build up. Then in the wintertime, when the sun is low in the sky, lots of sunlight can stream in beneath the overhang, warming the body and cheering the soul.

       Consider climate and weather factors when positioning a house on a site. The garage, the utility room, or other non-living spaces, can serve as a buffers against the weather. Rooms for living and sleeping usually have many windows and doors which causes them to be more vulnerable to severe weather. In harsh climates, you may want to protect those rooms by positioning the garage on the “weather side” of the house. Consider the classic farmhouse built in the middle of the American prairies. The barns and outbuildings would often be located to the northwest, to serve as a windbreak. The farmer would plant some shade trees to the south, giving the house shade in summer and then, after the leaves fall, needed sunlight and warmth was allowed to come through the branches and into the house in winter. This kind of design, simple as it may be, is quietly responsive to the environment in which it is situated. The barns and outbuildings placed to the northwest mean that the farmer and his family will stay warmer in the winter with less concern for the winter winds howling through their house.

If you would like to read more articles about house and home design, please visit my other website, www.about-home-design.com.

      Bill Hirsch

      www.designingyourperfecthouse.com

     I use SketchUp all the time. I’ve drawn everything from cabinetry ideas to entire houses. It take some time, but I’ve found it very useful to develop a 3D computer model of things like kitchen designs and then rotate them around, zooming in and out, to help me and my clients get a better feel for the design than a single, flat drawing could ever give.

      Another good use for SketchUp is to examine sun angles. Knowing the position of the sun is valuable information for passive solar and energy efficient, green design. The program lets you take even a rudimentary model of a house and place it anywhere on the planet. Then, you can orient the building relative to the compass by rotating it. SketchUp will then show the shadows for any time of the day for any day of the year. It’s a great tool to check your orientation relative tot he sun and also to see if your overhangs are the right size to shade the windows and walls in the hot summer, yet allow warming sunshine in during the winter months.

If you would like to read more articles about house and home design, please visit my other website, www.about-home-design.com.

      Bill Hirsch

      www.designingyourperfecthouse.com