Greenhouse or sunspace glare photo (C) Daniel FriedmanGreenhouse / Sunspace Glare Complaints & Solutions

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

This article discusses how to control direct and indirect glare caused by sunlight in green houses and sunspaces.

Green links show where you are. © Copyright 2017, All Rights Reserved.

Advice for Insulating a Greenhouse or Solarium Against Night Time Heat Loss

The accompanying text is reprinted/adapted/excerpted with permission from Solar Age Magazine - editor Steven Bliss. Our page top photos shows a sunspace constructed by the website editor (DF) and an example of indirect solar glare (to the right of the plant in our photograph).

Beating Sunspace or Greenhouse Glare in buildings

Question: what strategies are most promising for controlling indoor glare from sunlight or other sources?

A building we own and occupy has a three-story atrium/sunspace with over 30 2x5-foot windows. Our computer room faces the atrium and users complain about the glare.

We are considering installing shades or films to control the glare from sunlight. What solar glare strategies are most promising? - Lou Nemesec, Illinois Industrial Commission, Chicago IL

Answer: Solutions to Sunlight and Indoor Light Glare 

Greenhouse floor slab insulation retrofit (C) Daniel Friedman Steven BlissGlare can interfere with vision and cause discomfort, eye fatigue, and over time, eye damage, even contributing to cataract formation where UV wavelength light is also present.

Types of Light Glare: Indirect & Direct

There are two kinds of glare: direct glare and indirect glare.

Direct glare is caused by light coming directly into the eye from the light source.

Indirect glare is caused by reflected light (see our photo at page top).

Strategies for Controlling Glare in buildings

As we elaborate below, you can control glare and reduce glaring light complaints in buildings by one or more of the following six methods:

You can control glare by reducing the brightness or size of the light source, changing the position of the light source, or making the area around the light source brighter.

We assume that the complaints about glare come from long exposure, since short term exposure to glare can usually be tolerated. We also assume that you can't rearrange the building or room to change the relationship between the light source, work surface, and the workers themselves in order to change the angles of light and light reflection to simply eliminate the problem.

The size of the light source in your building too is fixed, unless you block out some of the entering sunlight with an opaque material.

So what measures are left to reduce indoor glaring light problems?

You could reduce the contrast between the incoming light and the surrounding surfaces by increasing the lighting level on the interior surfaces with electric lighting.

But it seems that your best bet is limiting the brightness of the light source.

Polyester solar screen used at a New York City construction site (C) Daniel Friedman

If you need year-round help, use window films. Window films can cut out anywhere from 45 to 86 percent of the incoming light. If view is not important, permanent louvers may do.

If you want seasonal control over glaring light, use movable or removable shades or blinds. Interior choices for glaring light source control include vertical or horizontal blinds(discussed in more detail at SOLAR SHADES & SUNSCREENS).

External choices for glaring light control include woven fiberglass shades or aluminum mini-louvers.

Details about solar shades are found at SOLAR SHADES & SUNSCREENS and SOLAR SHADES, LOW-E EFFECTIVENESS.

The original article below [PDF] is expanded and illustrated above:

The question-and-answer article on this pate paraphrases, quotes-from, updates, and comments an original article from Solar Age Magazine and written by Steven Bliss. Solar Age Magazine Articles on Renewable Energy, Energy Savings, Construction Practices

Sunspace & Solar Glazing & Shading Articles


Continue reading at SOLAR SHADES & SUNSCREENS or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Suggested citation for this web page

GREENHOUSE / SUNSPACE GLARE at - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.


Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia


Frequently Asked Questions (FAQs)

Click to Show or Hide FAQs

Ask a Question or Search InspectApedia

Questions & answers or comments about controlling glare problems at and in buildings .

Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

Search the InspectApedia website

Comment Box is loading comments...

Technical Reviewers & References

Click to Show or Hide Citations & References

Publisher's Google+ Page by Daniel Friedman