The Science of Experience



HVAC + SPF: Make Sure It's the Right Match

Posted by Emillie Lee

Nov 28, 2016 10:00:00 AM

ac.jpgimage via Brian Snelson

Spray foam is certainly a great choice when it comes to insulating your home. However, you do need to be careful when designing your other home systems. It's important that they are all compatible with the spray foam. Your HVAC system will have a different load with spray foam insulation than with other insulation choices, and it's important that it's properly configured for this.


HVAC systems in homes with polyurethane spray foam insulation need to be properly ventilated. The spray foam does not breathe in the same way fiberglass insulation does. In fact, it's very good at preventing leaks. As a result, your HVAC contractor must ensure that your home's system offers adequate ventilation to prevent stale air from accumulating indoors.

Moisture Considerations

If the air is very humid inside your home, it will deposit moisture as it moves through your walls. This can reduce your insulation's effectiveness and also contribute to mold growth. Your HVAC contractor must take this into account when programming your air conditioner for the cooling season. Shorter run-times will result in more effective dehumidifying of the air.

Load Calculations

The best way to make sure that the HVAC equipment is properly sized for a home is to calculate the necessary load. Different factors are used in this calculation when a home in insulated with polyurethane spray foam insulation than when it's insulated with traditional fiberglass. Not all HVAC contractors are familiar with load calculations for spray foam insulated homes. NFCI Polyurethanes can recommend contractors who are experienced in this skill.

NCFI Polyurethanes is your source of polyurethane products, information, and equipment. Contact us if you're looking for an HVAC contractor who has experience with spray foam, or if you're thinking of insulating your home with this excellent material.

Topics: Energy Efficiency, Spray Polyurethane, HVAC