As we start to creep into late fall and winter, cold weather becomes a concern for spray foam contractors. Cold chemical (material temperature in drums, totes or cylinders) leads to inefficient processing of chemical, additional startup time due to recirculation, potential performance issues regarding ratio and potential loss in yield. In order to maintain good starting chemical temperatures the following items can be recommended:
- Keep chemicals stored in a temperature controlled environment between 75F and 95F. Chemical rooms can be built in warehouses to keep a controlled environment for material.
- Utilize temperature controlled heat blankets during transport to minimize heat loss and maintain desired chemical temperature. (add temp control part numbers and request for pricing)
- Spray foam the bottom, sides and top of trailers to minimize heat sync loss during transport.
- Minimize chemicals from being stored on surfaces that can generate heat sync temperature loss. Keep chemicals up off the cold concrete or flooring.
- Open cell foam can be recirculated to bring the chemical up to a conditioned temperature. Please follow the instructions on your equipment if you have that option. NOTE: closed cell foam should never be recirculated as it can separate the blowing agent out of the polyol side. This will lead to potential issues with yield and foam performance. If your rig has a recirculation system you can follow these steps to recirculate: Take the gun off the hose, and place the coupling block from the hose, onto the the recirculation manifold block on the recirc system. Turn valves to the on position to recirculate. If you do not have a recirculation system on your rig, be sure to keep drums with items like Powerblankets and take the above listed steps to ensure your chemical will stay the appropriate temperature.
- Nitrosys System Recirculation: Leave the gun on the system, turn the system on to pre-heat, turn the output valves to re-circ mode and the system will start recirculating.
Chemical sitting exposed to ambient temperatures will lose 10 – 15 degrees towards ambient every hour. The chemical will only rise exposed to ambient temperatures 1 – 2 degrees every hour. This means that if chemical is at 80F and exposed to 50F, it would only take 2 -3 hours for the chemical to reach 50F. If the chemical is 50F and exposed to 80F, it could 15 – 30 hours to reach 80F. Lastly, please remember that polyurethane foam chemical is not freeze thaw stable.