It’s good to know that when choosing spray foam insulation that you have two options — open-cell or closed-cell. Both have pros and cons. Both have different prices. Both have unique qualities that make them ideal for specific types of projects. Here’s a summary of the differences for property owners. This outline should make it easier to understand when making a buying decision regarding your home or building.
Open-cell Foam Insulation
Open-cell foam is ideal for interior walls and raised floors in construction. While it is not quite as good an insulator as closed-cell, it is significantly less expensive than closed-cell insulation. It should also be noted though, that it is still a far superior insulator compared to traditional insulation materials.
Another key characteristic is that it provides a better sound barrier than any other insulation option, including closed-cell spray foam. Better sound insulation can be a very desirable feature. When applied between interior rooms, either in the floor or walls, one can enjoy total solitude from anything else going on in adjacent rooms, including loud music and large home theater systems. Technically speaking, open-cell foam has ½ lb. density compared to closed-cell foam which has a 2 lb. density. This simply means that it is better at absorbing vibrations, thus reducing the sound carried between rooms.
These characteristics mean that it is the product of choice for media rooms or any room where a quiet environment is important or where noise needs to be contained. Bedrooms of teenage boys, or personal offices may be a primary use for this product!
Open-cell foam is also the foam of choice when injecting foam into insulating existing walls. With some projects it just doesn’t make sense to tear out old walls. In these cases the preference is to inject foam into the spaces in-between the studs. Open-cell provides the only good option for insulating these properties.
Closed-cell Foam Insulation
Closed-cell foam is ideal for exterior walls, crawl spaces, basements, attics and flat roofs. Any application in fact where efficient temperature and weather insulation is the priority is a great fit for closed-cell.
Closed-cell foam also has the added benefit that it can help improve structural strength and also acts as an inherent air barrier. This will reduce drafts and can help reduce intrusion into a structure by pollen, dust and other contaminants.
Lastly, closed-cell foam insulation has an excellent resistance to water and low moisture vapor permeability. This means it can also act as a great vapor barrier in specialist applications such as residential wine cellars.
More Useful Facts About Both Types of Spray Foam
Spray polyurethane foam insulation expands 120 times its initial volume and as a result fills cavities of pretty much any shape. This provides a continuous, protective air barrier that helps to minimize air leakage and air intrusion.
Improved energy efficiency is becoming a higher priority as we see energy costs increase, along with greater awareness of our environment, and the need to protect it.
The building envelope is the physical separator between the interior and exterior of a building, The selection of green building products that enable building envelopes to have enhanced insulation levels are becoming standard practice. Consumers are becoming increasingly aware of these issues. This fact, coupled with the recent availability of tax credits and energy rebates is driving the careful selection of energy efficient products such as spray foam insulation.
Technical Differences Open-cell vs. Closed-cell for Commercial Technicians, Designers and Contractors
Open-cell Foam Insulation More Detail
Open-cell foam insulation is a thermal insulation material which is spray-applied. It has a half pound density and is non-structural. Ideally it should be used for internal wall cavities, floor and ceiling assemblies and in applications where sound insulation is a priority. Open-cell spray foam insulation has aged R-Values of 3.9 per inch.
Open-cell foam insulation provides a significant performance upgrade over conventional insulation products. Its application leads directly to improved energy efficiency and occupancy comfort. It provides a cleaner indoor environment along with greater noise reduction for commercial buildings and residences.
Open-cell spray foam technology is a cost-effective solution to improve the energy efficiency of a building.
Closed-cell Foam Insulation More Detail
One of the most efficient insulating materials commercially available, closed-cell spray foam insulation has aged R-Values above 6.0 per inch.
Properly installed closed-cell spray foam insulation frequently achieves energy savings as high as 45% over conventional insulation products.
In a typical building’s structural envelope, small imperfections such as cracks, holes and gaps are often poorly sealed. Over time these lead to poor building performance or worse, moisture accumulation, allergen/pathogen growth, and in extreme cases structural failure.
The sealing capability and solid nature of closed-cell spray foam, significantly inhibits moisture-driven intrusions. Just two inches of closed-cell spray polyurethane foam insulation will dramatically reduce air exfiltration and infiltration. It will also reduce conduction, convection, and reduce solar driven moisture within the building envelope.
The name “closed-cell” is based on the structure of the finished cell based insulation material. There are literally millions of very small closed-cells within every cubic inch of the insulation material. These are filled with Enovate® 3000. Enovate® 3000 is a non-ozone depleting blowing agent.
This blowing agent which is captured within the individual cells, contributes to highly efficient insulating properties of the material. This “closed-cell” form of the spray foam product enables the material to become a highly efficient air barrier as well as having an inherent resistance to water and low moisture vapor permeability.
The density of closed-cell spray foam is approximately two pounds per cubic foot. This is what enables the foam to also provide both sheer and racking strength to wall assemblies in building applications.
Closed-Cell vs. Open-Cell Spray Insulation Performance Comparison
|Properties||Open Cell SPF||Closed Cell SPF|
|Aged R-Value(ASTM C-518)||3.9/inch||6.3/inch|
|Density(ASTM D-1622)||0.4 – 0.6 pcf||1.8 – 2.2 pcf|
|pen Cells(ASTM D-2856)||>90%|
|Closed Cells(ASTM D-6226)||≥5 lb/in2||≥15 lb/in2
|Air Permeance(ASTM E-2178, E-283)||< 0.2 L/s-m2
at 4½” Thickness
|< 0.2 L/s-m2
at 2″ Thickness
|Surface Burn Characteristic
|Class 1||Class 1|
|Water Vapor Permeance
|<1 perm at 2 inches
Resistant to Flood
|Blowing Agent||Water/CO2 only||Water/CO2 and 245fa|