Solar Screens vs Standard Sun Screens: Cleaning, Care and When to Replace

The short answer: openness factor is the whole difference

Standard sun screen, the gray mesh that came with the window, is fiberglass strand about 0.011 inch thick, woven 18 by 16 to the inch, weighing roughly 4 to 5 ounces per square yard. Its job is insects. It blocks maybe 25 to 30 percent of solar heat as a side effect. Solar screen is a different material: vinyl-coated polyester or fiberglass woven flat and tight, 15 to 18 ounces per square yard, sold by openness factor. A 90 percent solar screen leaves about 10 percent of its area open and stops roughly 90 percent of the sun's energy before it touches your glass. Eighty percent fabric leaves twice the opening and more of the view. Trade names on the selvage are usually SunTex, Textilene or Twitchell. The naming is regional and useless: in Phoenix, sun screen means solar screen; in Idaho it usually means the bug screen. Ask for the openness number, not the name.

How to tell which one you have in thirty seconds

Pick the panel up. A three by five foot insect screen weighs about a pound and a half. The same size in 90 percent solar fabric is closer to four. Hold it to the light. Standard mesh is round strands in an obvious square grid you can count with your eye. Solar fabric is flat, ribbon-like strands, often laid at a slight angle, and the weave reads as solid dark rather than as a grid. Then look at your house from the street at midday. If you cannot see into the room at all, that is solar screen doing its job. Check the frame stock too. Standard screens ride in 5/16 inch roll-formed aluminum. Solar fabric needs 7/16 or 3/4 inch, and anything wider than about 36 inches should have a center crossbar. Solar fabric tensioned into a 5/16 frame bows the rails inward and never seats right in the track.

Cleaning: the coating is the product, so stop scrubbing it

Take them out of the window first. Cleaning a screen in place drives everything in the weave onto the glass and into the track, and you never reach the back side. Number them with painter's tape as you pull them, because screens are not interchangeable even when they look identical; frames commonly vary an eighth of an inch. Use a soft-bristle brush and plain water. No bleach, no ammonia, no degreaser, no citrus solvent, no melamine sponge. On solar fabric the vinyl coating is the entire product, and the polyester core under it has almost no UV resistance of its own. Anything that abrades or dissolves that coating costs you years. Never put a pressure washer on a screen. A garden hose runs 40 to 60 PSI and is plenty; a 1,500 PSI tip at close range pops mesh out of the spline channel or embosses the pattern permanently. Dry them leaning at an angle so water sheets off instead of pooling in the bottom rail.

Hard water, high-desert UV, smoke season and the winter question

Treasure Valley tap water runs hard, commonly 7 to 12 grains, so a hose rinse left to air-dry on a black solar screen leaves white speckle across the panel, worse than on standard mesh because the tighter weave holds more droplets. We run 100 percent deionized water and no soap for that reason: nothing is left in the water to dry into the weave. Boise sits near 2,700 feet, UV climbs about 4 percent per 1,000 feet of elevation, and the valley gets roughly 200 sunny days, so screens age fast here. Late-August and September smoke is what actually loads a screen; fine ash packs into a 90 percent weave and stays. Clean after smoke season, not in June. And at 43.6 degrees north the December noon sun is only about 23 degrees up, so solar screens block exactly the heat you want in January. Pull them in November, store them on edge and out of the sun, and you get a brighter winter plus a few extra years of fabric.

Replace, rescreen, or leave it alone: three tests

Chalk test: run a white rag across dark solar fabric. If colored powder transfers, the vinyl coating is chalking off and the fabric is done; cleaning from that point only speeds it up. Brittleness: fold a corner of fiberglass insect mesh back on itself. If strands crack or the crease stays, that screen is past 10 years and finished. Sag: press the center. More than about an inch of belly means the fabric has taken a set, and stretched screen cannot be retensioned. Pulling the spline and restretching gives you a wrinkled panel, not a tight one. If the fabric is sound and has only pulled out of the channel at one corner, that is a spline job, not a replacement. Fiberglass rescreen materials run 8 to 15 dollars a panel; a shop charges 20 to 40. New custom solar screens run roughly 6 to 12 dollars per square foot installed, so a three by five window is about 90 to 180 dollars and a 15-window house lands between 1,200 and 2,500.

What we will tell you not to pay for

If your screens are dusty but the fabric is sound, hose them yourself. A whole house takes about 20 minutes with a soft brush, and paying anyone 50 dollars for that is money you did not need to spend. Do not buy solar screens for north-facing windows either; at Boise's latitude a true north window takes direct sun only near sunrise and sunset around the June solstice, so a screen there darkens the room and saves almost nothing. Order south and west first, east second, north basically never. We also will not clean chalked fabric. It looks worse afterward and we would be charging you to shorten its life. Some things cannot be fixed: creases set in by stacking screens flat, mineral etch already in the weave, and frames warped by reflection off a bowed low-E window next door, which is real and gets hot enough to distort vinyl. Screens are a 50 dollar add-on here, and Monthly and Quarterly members get one screen cleaning a year included, so check your plan first.