Schematic of a solar water heater hookup (C) - Lennox Industries Use of Phenolic Foam Insulation for Solar Energy Applications

  • PHENOLIC FOAM INSULATION - CONTENTS: How suitable are phenolic foam insulation products for solar energy applications? Solar Age Magazine Articles on Renewable Energy, Energy Savings, Construction Practices
  • POST a QUESTION or READ FAQs about using phenolic foam insulation products in buildings or in the construction of solar energy system components

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

Phenolic foam insulation properties: this article discusses the question: is phenolic foam insulation suitable for solar energy installations?

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

Indoor use of phenolic foam insulating materials in solar energy systems

Sketch at page top and accompanying text are reprinted/adapted/excerpted with permission from Solar Age Magazine - editor Steven Bliss.

The question-and-answer article about the indoor use of phenolic insulating foam found just below paraphrases, quotes-from, updates, and comments an original article from Solar Age Magazine and written by Steven Bliss.

Are Phenolic Foam Insulation Board Products Suitable for Solar Energy Products or Designs?

We wish to obtain information about manufacturing sources for phenolic insulation materials. As this material is rated as high as 500 degF. in temperature range, it may well suit a specific solar application that we have. -- J.I. Osias, Solar Builders, Cheshire CT.


Phenolic foams, like polyurethanes and isocyanurates, are closed-cell insulations with entrapped Freon gas [or by current standards, non-freon gases]. A chief attraction of phenolics is that they can withstand high temperatures and will not support flames (though they can be consumed) in a fire.

Typically, phenolic foams can tolerate continuous temperatures in the 300 degF to 350 degF range, with intermittent use up to 400 degF. Above that temperature, oxidation is likely to occur and render the phenolic foam insulating boards brittle. Outgassing of Freon or its replacement gases at high temperatures should be less of a problem than with other refrigerant-gas blown foams. In general, the phenolics are very stable chemically and dimensionally.

The main problems with phenolic foams reported in the 1980's were their relatively low compressive and flexural strength and their friability or tendency to crumble. Continual improvements in the formulations of phenolic foam board insulation products may overcome these drawbacks.

Facings on the foam insulating board can also help, but at the time of the original Solar Age article (August 1984) no one had successfully foamed phenolics between foil facings. At that time Koppers Co. was about to release a foil-faced phenolic foam insulation called Exeltherm Xtra residential insulation. At R-8.2 per inch, that foam would have had the highest R-value of any residential insulation. See INSULATION R-VALUES & PROPERTIES for current R-values.

More information about companies producing phenolic foam insulation products is provided at Technical References & Reviewers below.

Here we include solar energy, solar heating, solar hot water, and related building energy efficiency improvement articles reprinted/adapted/excerpted with permission from Solar Age Magazine - editor Steven Bliss.

Original article

Reader Comment: warnings about using phenolic insluation in low slope roofing systems

7/10/2014 Kim Lawson said:

The presence of phenolic insulation should be carefully considered. Currently, July 2014, membrane roofing manufacturers will not issue a warranty on new roofing on buildings which had phenolic insulation. The reason is that phenolic dust, once introduced to moisture, can become very acidic and damage surrounding materials. I would suggest this topic be investigated and appropriately discussed on this website.

Reply: research citations on phenolic roof insulation properties, wear, suitability, damage & wear

Thanks Kim for the interesting and important comment.

Here are some research citations, discussing the observation that phenolic insulation can cause damage


Continue reading at FOAM SPRAY INSULATION TYPES or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.



Suggested citation for this web page

PHENOLIC FOAM INSULATION 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 using phenolic foam insulation products in buildings or in the construction of solar energy system components.

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