Quick wins for a faster PC:
Scan for outdated or missing drivers - takes under a minuteDriver Scan →Clear out junk files and repair common Windows errorsFree Scan →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →
ThatPainter is reader-supported. When you buy through links on our site, we may earn an affiliate commission. Learn More
Energy-efficient windows are not defined by size or technology alone. They work when their orientation, glazing, shading, ventilation role and operability match the local climate and the way people use the room. A window can bring daylight, warmth and a view, yet it is also a comparatively vulnerable part of the building envelope. The design task is to keep the benefits while limiting unwanted heat, glare and drafts.
That is the central argument in Ruthie Blum’s 2014 feature, “Israeli opening a window onto energy conservation”, about Evyatar Erell’s work at Ben-Gurion University’s desert research institute. The article describes guidance developed in an Israeli and desert-climate context; its examples are useful principles, not universal building-code rules.
As an Amazon Associate I earn from qualifying purchases.
Why a window is an energy-design decision
Windows influence several building loads at once. Their area and position affect how much sun enters, how far daylight reaches, where glare appears, whether occupants can see outside, and how furniture can be arranged. An operable opening can also support natural ventilation. Those benefits can reduce dependence on electric lighting, mechanical cooling or heating, but only when the opening behaves well during the relevant season.
Erell describes a window as a potential weak point in the envelope: a large opening may admit useful winter sun but also unwanted summer heat; a clear view may come with glare; and a room designed around daylight may become uncomfortable if the glass cannot be shaded. The right question is therefore not “How much glass can this facade hold?” but “What job must this opening perform in this climate and room?”
#1 Best Overall
- COMPLETE 5-PIECE BRUSH SET FOR EVERY PAINTING TASK — Includes 1 Inch Flat, 1.5 Inch Angle, 2 Inch Flat, 2 Inch Angle Stubby, and 2.5 Inch Angle brush giving you every size professional painters use daily. Get all 5 for less than the price of a single brush from hardware store brands — professional grade performance at a fraction of the cost. Perfect for walls, trim, cabinets, doors, furniture, and detailed cutting-in work on any project.
- ZERO BRISTLE LOSS — GUARANTEED BY PRECISION ADHESIVE BONDING — Every bristle is locked in place with precision-set adhesive that keeps them in the brush — not in your paint job. The coated steel ferrule provides structural support while the adhesive bond ensures clean performance on every stroke. Premium SRT synthetic filaments load more paint and release it evenly for a smooth streak-free finish on walls, ceilings, and trim. Works with latex, oil-based paint, primer, sealer, and wood stain.
- INCLUDES THE ANGLE STUBBY MOST SETS LEAVE OUT — Professional painters know the 2 Inch Angle Stubby is the go-to brush for tight cabinet interiors, window sashes, inside corners, and detailed trim where standard angle brushes are too long. Combined with the 1.5 and 2.5 inch angle sash brushes you have precision cutting-in covered at every scale — baseboards, crown molding, door casings, and ceiling lines.
- FLAT BRUSHES FOR BROAD SMOOTH COVERAGE ON ANY SURFACE — The 1 and 2 inch flat brushes deliver even coverage on walls, furniture, shelving, doors, fences, decks, and wood surfaces. Ideal for applying primers, stains, varnishes, polyurethane, and specialty coatings. Solid wood handles provide all-day comfort and control for both professional contractors and weekend DIY homeowners tackling interior or exterior painting projects.
- TRUSTED BY PROFESSIONAL PAINTERS AND CONTRACTORS NATIONWIDE — Pro Grade delivers professional-grade results at a price that makes sense for crews who go through brushes on every job. Ideal for property managers, remodeling contractors, apartment turnover crews, maintenance teams, and commercial painting operations. Backed by thousands of verified reviews from working painters. Washable and reusable for multiple projects.
In the feature, Erell summarizes building energy responsibility in three parts: “One is the correct planning of its envelope. The second is selecting efficient equipment and appliances. The third is us. People.” Window design belongs mainly to the first part, but the third matters because occupants open, close, shade and ventilate the building in real time.
Start with climate, not a universal orientation rule
Solar angles, prevailing breezes, humidity, heating needs and cooling seasons differ from place to place. A window strategy that works in an Israeli desert setting can produce glare or overheating elsewhere. Before choosing an orientation, map the local conditions and the room’s schedule: when the room is occupied, when sunlight is welcome, when cooling is required and whether outdoor air is acceptable.
The feature gives two orientation examples for Israel. South-facing windows can provide winter light and warmth, while north-facing windows can support cross-ventilation. These are attributed examples from that context, not prescriptions for every latitude or hemisphere. A designer elsewhere should treat them as hypotheses to test against the sun path and prevailing wind direction for the actual site.
| Design question | What the Israeli example suggests | What must be checked locally |
|---|---|---|
| South-facing glass | Potential winter daylight and solar warmth. | Summer sun angle, shading depth, cooling demand and glare at the actual latitude. |
| North-facing openings | Potential support for cross-ventilation. | Whether the local prevailing winds, air quality, security and neighboring buildings make that airflow practical. |
| Any orientation | Can deliver daylight, a view and ventilation if sized and operated appropriately. | Seasonal heat gain, privacy, furniture placement, condensation risk and the occupants’ willingness to operate the opening. |
Balance the five jobs a window may perform
Daylight
Window height and position influence how deeply daylight penetrates a room. A high opening can send light farther across a ceiling and wall, while a low opening may prioritize a view or seated eye level. The useful area is not simply the glazed area: walls, ceilings, adjacent buildings and interior finishes all affect how light is distributed. Plan the opening with the room’s work surfaces in mind so that daylight reaches the places where people read, cook or work.
Solar warmth
Sun entering through glass can be helpful during a heating season and troublesome during a cooling season. The same opening may therefore need different treatment at different times of year. Exterior shading, interior shades or an adjustable element can block direct sun when it is excessive while preserving diffuse daylight. Do not assume that a permanently darkened pane is the only answer; it can reduce useful winter light and views as well.
Rank #2
- Great Value Pack Artist Paint Brushes: Soucolor 20 brushes in 10 sizes professional paintbrushes set — no shedding, holds paint well, cleans easily, Acrylic, watercolor, oil, gouache, Halloween pumpkin decoration & face painting, rock painting, ceramics. Fantastic high quality gifts for creative, artistic siblings to share!
- Awesome Set of Paint brushes: Professional paint brushes can cover all of your needs. The multi-purposed brushes are ideal for Watercolor, Oil, Gouache, enamel, Acrylic Painting, Body, Nail, Face Painting, Miniature, Model, Wood, Glass, Cup, Ceramic, Fine work, Art class, Craft Art Painting, DIY Art Crafts etc.
- Soft and long-lasting: The bristles are soft and strong, with nickel metal ferrules and blue wooden handles. After cleaning, the bristles will become soft and fluffy again and will not fall off.
- Easy to clean: it’s very convenient to Wash well in soap and water. Retain shape after drying. the brushes hold up very well. Nice selection to beginners and professionals. Keep them clean and they last a long time.
- Halloween Pumpkin Ceramic Crafts Supplies: A Great painting gift for family, friends, kids, girls, women, student, classmate, teacher. For using in school, travel or used in the home and office.
Glare control
Glare is an occupant-comfort problem as well as a layout problem. A bright patch on a monitor, a reflective worktop or a television screen can make a well-lit room hard to use. Place desks and seating so that direct sun is not aimed at the user’s field of view, and provide a means of adjusting the incoming light. The feature’s emphasis on comfort is explicit: “It has to be comfortable. And if we can live comfortably and also conserve energy, that’s great.”
Do these 3 things before closing this tab:
1Clear out junk files and repair common Windows errors2Fix the driver behind crashes, sound loss and screen glitches3Repair Windows errors before they cause bigger problemsViews and privacy
A window is valuable partly because people can look through it. Erell asks, “What is the point of having a window, if you never open it or look out of it?” That observation argues against treating energy performance as a reason to eliminate every view. Instead, decide which sightlines matter, then use sill height, screening or selective glazing to protect privacy without making the opening unusable.
Ventilation
Operable windows can connect rooms to outdoor air, but effective cross-ventilation requires more than putting two openings on a plan. Air needs a path through the occupied zone, and the outdoor conditions must be suitable. Internal doors, security screens, noise, pollution and wind pressure can all determine whether occupants actually open the windows. A ventilation strategy should identify both an inlet and an outlet and explain when each is operated.
Use light shelves to move daylight deeper into the room
A light shelf is a horizontal surface placed at or near window height. Its upper surface reflects daylight toward the ceiling, helping distribute light farther from the facade while the lower portion of the opening can remain useful for a view. The feature reports that a shelf can be adjusted for seasonal conditions. In practice, that means its position or angle should be considered alongside the sun’s changing path, shading requirements and maintenance access.
Light shelves are not a cure for every glare or heat problem. A reflective surface that catches low-angle sun may create a bright spot, and an exterior shelf must be detailed for weather, drainage and cleaning. Treat it as part of a coordinated window assembly rather than an accessory added after the facade is designed.
Rank #3
- 【All sizes of art brushes】: The 10 sizes of multi-functional brushes have various shapes, making the mixing color easier, which is very suitable for artists, students, teenagers, children and painters at all levels. Wonderful Present ideas for friends and family who like painting!
- 【general brush set】: Professional paint brush can meet all your needs. Multifunctional brush is very suitable for watercolor, oil, gouache, acrylic painting, body, nail, face painting, miniature, model, ceramics, arts and crafts painting, etc.
- 【high quality process】: It is designed with anti falling bristles, anti-rust nickel ferrule and solid wood handle. You can use the brush to focus on the painting and always be creative.
- 【easy to maintain】: After using the brush, it is very convenient to clean the brush with warm soapy water and reshape the tip of the brush. Air dry the brush and place it on top of the top for long use.
- 【100% satisfaction guarantee - buy now】1 packs of set brushes, you can also get friendly customer service, any questions feel free to contact us, within 24 hours to help you! There is no risk in buying our paint brush kit.
The Seasons window prototype
The article describes Erell’s Seasons window as a prototype intended to admit or exclude sun and heat while supporting thermal and visual comfort. Its frame could rotate. One pane was clear and weather-tight; an additional pane was tinted. Rotating the assembly allowed the occupant or designer to change the relationship between the opening, sunlight and the room.
The concept illustrates a broader principle: seasonal performance can come from changing the window’s configuration instead of accepting one fixed compromise. A clear setting can favor daylight and a view; a tinted setting can limit intense sun. Any movable system, however, needs a clear operating method, durable seals, safe access and a maintenance plan.
The 2014 feature says the Seasons project had not been sold in Israel because marketing fell through. That is a historical status report, not evidence of present-day availability. No current seller, specification, energy rating or independent performance result is established here, so the prototype should be treated as a design concept rather than a product recommendation.
A practical method for designing or renovating a window
- Define the room’s priorities. Record whether the primary need is winter warmth, summer cooling, diffuse daylight, a particular view, privacy or natural ventilation. Rank the priorities instead of assuming they are equal.
- Map sun and wind for the site. Check the actual latitude, seasonal sun path, neighboring obstructions and prevailing breezes. Do not transfer the Israeli south- and north-facing examples without this check.
- Choose opening locations with the interior plan. Mark desks, beds, screens, cooking surfaces and circulation routes. Keep likely glare angles away from critical tasks and preserve the sightlines occupants value.
- Separate fixed and operable areas. A fixed pane can provide a stable view and daylight, while a smaller operable section can supply ventilation. Make the operating hardware reachable and understandable.
- Plan shading before selecting glass. Decide how direct sun will be blocked in the cooling season and admitted when warmth is useful. Consider exterior devices, interior shades, light shelves or an adjustable assembly as a coordinated system.
- Check airflow paths. Identify where air enters and leaves, and verify that interior doors, screens and security measures will not defeat the intended path.
- Review comfort at different times. Walk through morning, midday and late-afternoon conditions in both warm and cool seasons. Look for glare, hot surfaces, cold downdrafts, condensation and loss of privacy.
- Document operation and upkeep. Give occupants simple instructions for opening, shading and seasonal adjustment. Include cleaning, seal inspection, hardware access and replacement of worn components in the maintenance plan.
How to compare window and shading choices
The feature does not provide product-level performance figures or a quantitative ranking. A useful comparison therefore asks the same questions of every option rather than assigning a score that the evidence cannot support.
Recommended Free Tools
| Decision axis | Questions to ask |
|---|---|
| Climate and orientation | Does the option suit the site’s sun path, wind, heating season and cooling season? |
| Seasonal solar gain | Can occupants admit useful warmth and block excessive heat at different times of year? |
| Daylight and glare | Does it light the work area without creating reflections or uncomfortable brightness? |
| Cross-ventilation | Are there operable openings and a realistic path for air through the room? |
| Privacy and views | Does the arrangement preserve important sightlines while controlling unwanted visibility? |
| Occupant comfort | Can people adjust the system easily, and does it avoid hot spots, drafts and visual discomfort? |
| Cost and maintenance | What installation, cleaning, hardware and replacement obligations accompany the design? |
Common mistakes and how to correct them
Copying an orientation rule
Symptom: A plan labels one facade “best” without checking the site.
Rank #4
- Bates paint brushes come in a convenient 6 pieces with 3 flat and 3 angled bristle styles, including (1”, 1.5”, 2”) flat and (1.5”, 2”, 2.5”) angled bristles, perfect for tackling any surface painting or staining job.
- The sturdy natural bristles of each brush are designed to hold more paint, creating a smoother finish with fewer streaks and saving you time on the job.
- The lightweight wooden handles provide extra comfort and ease during long painting processes like walls, trims, cabinets, and doors.
- These versatile brushes are ready-to-use, easy to clean, and can be reused multiple times, making them economical as well as reliable tools for any painting project.
- Bates paint brushes can be used for both oil-based paints as well as latex stains and are ideal for home or commercial projects such as decks, fences or DIY painting jobs.
Correction: Recalculate solar and wind conditions for the project’s geography. The source’s orientation advice is specifically presented in an Israeli context.
Making the glass area the goal
Symptom: A larger window is added for daylight, then blinds stay closed because of glare or heat.
Correction: Compare the desired daylight zone with the room layout, add adjustable shading and test the opening at occupied workstations.
The Tool Desk
Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →Ignoring operation
Symptom: A theoretically ventilating window remains shut because it is difficult to reach, unsafe, noisy or confusing.
Correction: Put controls within reach, define safe operating conditions and provide a clear seasonal routine.
Best Value
- 2 Inch Angled Paint Brush for Precision Cutting-In – Designed for clean, sharp lines around trim, baseboards, ceilings, corners, and detailed edge work. The perfect size for control and coverage.
- Value 3-Pack for Pros & DIY Projects – Includes three professional 2-inch angled sash brushes — ideal for contractors, remodelers, and homeowners tackling multiple rooms or repeat paint jobs.
- Smooth Results on Walls, Trim & Cabinets – Great for interior wall painting, cabinet edges, furniture projects, and trim work where a smooth finish and crisp control matter most.
- Works with Latex Paint, Oil-Based Paint & Stains – Premium synthetic filaments hold more paint, reduce streaks, and provide a clean finish with latex paints, oil coatings, and wood stains.
- Works with Latex Paint, Oil-Based Paint & Stains – Premium synthetic filaments hold more paint, reduce streaks, and provide a clean finish with latex paints, oil coatings, and wood stains.
Treating a prototype as a current product
Symptom: Project documents specify the Seasons window as though a verified commercial model were available.
Correction: Confirm present availability and technical documentation independently. The cited article only records that marketing had fallen through by 2014.
What the evidence can—and cannot—tell you
The strongest source for this topic is a January 3, 2014 journalistic feature, not a current building code, product test or independent energy study. It supports climate-responsive design principles, the Israeli orientation examples, the light-shelf discussion and the description of the Seasons prototype. It does not establish a percentage reduction in energy use, a universal orientation formula, current product availability or compliance with any present-day regulation.
For a real project, use the article as a design prompt and then verify local code, climate data, safety requirements, glazing specifications and professional calculations. Those checks are necessary because window performance depends on the complete assembly and on occupant behavior, not on a single feature in isolation.
Quick Recap
Key takeaways for an energy-conscious window
- Begin with the local climate and the room’s use.
- Balance daylight, warmth, glare, views, privacy and ventilation rather than maximizing one attribute.
- Use the Israeli south-facing and north-facing examples only as context-specific guidance.
- Consider adjustable shading or light-redirection elements so the same opening can respond to seasonal conditions.
- Design for real occupants: controls, reachability and comfort determine whether the intended energy strategy is used.
- Verify any prototype or product’s current status before specifying it.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
