Applicator Bulletin: Conversion from HFC to HFO Blown Closed Cell Foams
The spray foam industry is experiencing a major shift from HFC blowing agents to HFO blowing agents for closed-cell insulation foams. States are passing laws mandating the use of HFO blown foam in their state.
This change aims to reduce environmental impact, improve product performance, and meet updated regulatory standards. Let’s take a closer look at the differences between HFC and HFO spray foam and why HFO is becoming the preferred choice.
What is HFO Spray Foam?
HFO, or hydrofluoroolefin, is a new generation of blowing agents to create closed-cell foam insulation. With zero Ozone Depletion Potential (ODP), HFO-based foams are known for their lower environmental impact, better energy efficiency, and improved performance.
HFC vs. HFO: Key Differences
While HFC (hydrofluorocarbon) and HFO (hydrofluoroolefin) blowing agents may seem similar, their environmental impact, thermal performance, and application qualities are quite different.
Environmental Impact
HFCs are potent greenhouse gasses with high global warming potential (GWP), meaning they trap significantly more heat in the atmosphere compared to carbon dioxide. HFOs, in contrast, have a much lower GWP, making them a greener alternative.
By switching to HFO spray foam, the construction industry is reducing emissions and helping meet sustainability goals.
Performance
HFO-blown spray foams generally offer superior thermal insulation due to their finer, more consistent cell structure. For homeowners and builders, this improved efficiency translates to long-term energy savings and better temperature control in buildings.
Safety
HFO spray foams are less flammable and less toxic than HFC spray foams. This makes them a safer option for homeowners and contractors like you that are actually doing the work.
What Contractors Need to Know About Transitioning to HFO Spray Foam
NCFI has formulated systems which incorporate the low GWP blowing agent HFO 1233zd (Solstice). This new ingredient is not compatible with many of the raw materials commonly used in spray and pour foams. Contractors and in-plant personnel should exercise caution when transitioning from the current HFC blown foams to the new formulations.
Storage & Handling
The boiling point of HFO 1233zd is slightly higher than HFC 245fa, so handling may be slightly more forgiving. Vapor pressures of the two blowing agent resin blends are still similar enough that the same precautions in storage and handling should be maintained.
Holding Tanks & Recirculating Lines
B-side (resin) holding tanks (including day tanks) and recirculating lines must be completely drained before refilling with HFO blown product.
This refilling should be promptly (within hours) run through the spray or pour equipment to avoid any material clinging to the tank walls negatively reacting with the resin.
It may not be necessary to use up the entire tank, but using enough of the tank to the prior level before draining will help avoid contamination.
Drum Pumps
If using drum pumps, the resin pump wet well should be emptied and the wet surface should be wiped clean before inserting into the HFO blown resin drum. Promptly pump enough of the foam to completely purge the equipment.
The foam should be of acceptable quality so that the finished foam can be utilized on a job (just as normally switching from one drum to another).
The movement of resin under pressure through the hoses, pumps and heaters will ensure that equipment is purged cleanly. Do not pump HFO blown resin into the machine and let it sit—pump it out.
HFO blown resins will not affect machine components or hoses, but resins blown with HFCs and HFOs intermingled in the machine and hoses and left unpurged will produce foam with coarse cells and poor physical properties.
The amount of material required to properly purge your equipment will vary according to machine type and hose length. If you are unsure of the quantity needed, call NCFI with the particulars of your machine set up and our technical service department can assist you.
It is essential that pour ups of partial drums be segregated. Do not intermix the two blowing agents since the two resins are incompatible. The longer the two liquids are mingled, the greater the impact on cell structure and ability to produce a quality end product.
Contact the Oak Ridge Team with Questions
If there are questions, contact your account manager or the technical service department at 920-561-2191.
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