As we mentioned, the main material is only part of what makes a door energy-efficient. The insulation, frame, glass, and weatherstripping all factor into the door's R-value, U-factor, and overall energy efficiency.
Fiberglass and insulated steel exterior doors offer the best energy efficiency ratings because they're manufactured with interior cores designed to reduce energy transfer.
The best energy-efficient doors you can buy right now are the Emerson Therma-Tru fiberglass and Masonite Steel Primed doors. These doors have a polyurethane foam core – one of the most energy-efficient materials on the market – placed in the middle.
Wooden Doors
Being naturally insulating, they are excellent at retaining heat inside. For interior or external doors, a solid wood door is an excellent option for helping to keep your home warm.
Best Types of Energy-Efficient Doors
While fiberglass, aluminum and steel are great exterior door options, the best kind of energy-efficient interior door is veneer wood doors. While a solid wood door provides some insulation, doors with insulating cores are more energy-efficient.
Steel. Steel is the best material for a front door if security is your top priority. This tough metal is stronger than all other door products. It provides excellent protection against forced entries and is less likely to crack or warp.
Contrary to popular belief, closing your bedroom doors does not improve the efficiency of your HVAC system and may actually increase your utility bills. When you close a bedroom door, you effectively block the air's pathway, and that blockage can lead to issues with airflow.
A fiberglass front door is your best bet for peak energy efficiency. Fiberglass doors have an exceptionally insulating polyurethane foam core that provides a high R-value. The R-value is a standard measure of insulation effectiveness; higher numbers mean better insulation.
Steel doors traditionally are foam filled and have a higher r-value than wood or glass. For many, the limited design choices available in steel doors coupled with the maintenance requirements make steel a poor exterior door choice.
Composite doors deliver superior energy efficiency due to their construction. The process involved in manufacturing these energy efficient doors is different from that used to create those made with just a singular material.
And steel can get hot when exposed to sunlight and high temperatures, which makes it a little less efficient than fiberglass. Verdict: While both steel and fiberglass are energy-efficient options, fiberglass outperforms steel in this area, making it a favorite door replacement option for many homeowners.
This means a fiberglass or steel door that's 1-1/2 inches thick will have five times more insulating value than a solid wood door of the same thickness. The best energy efficient doors also have tighter-fitting frames and if they contain glass, it's double-pane or triple-pane insulating glass to limit heat transfer.
Low Energy Doors are automatic swing doors that must be opened specifically via a Knowing Act device, such as a push plate, touchless actuator or wireless button (per ANSI standards). These doors require less kinetic energy to open and close as compared to Full Energy Doors.
Steel and fiberglass front doors require the least amount of maintenance. They're made from durable materials that resist dents and scratches, with a long-lasting finish. Wood front doors require a bit more maintenance if you choose a wood exterior.
A high-quality set of external doors, complete with double-glazing, will have a U-value of around 1.6. If you're willing to invest a little more, then you'll find that this number can fall down even further. For comparison, an insulated cavity wall can offer a U-value of around 0.5.
Rigid foam board insulation is available in many materials, including polystyrene (R-3.8 to R-5.0), polyurethane (R-5.5 to R-6.5) and polyisocyanurate (R-5.6 to R-8.0). Since it has the highest R-value, rigid foam is typically reserved for foundations and basement walls.
They don't tend to be the most energy efficient doors on the market, and the wood can also absorb moisture from the air, which can cause mold to grow on the door. Because of wood's ability to bend, bow or twist, wood doors also require more maintenance than fiberglass or steel.
Spray Insulation Foam into the Door
Spray some foam into each hole, using a straw or tube to help you. The foam will begin to expand immediately, so take care not to over-fill the door. Stop if you see excess foam escaping.
You Can Insulate a Non-Insulated Model
Mineral wool blankets – You can find them easily in hardware and home improvement stores. They are also found as kits that include the rolls, the reflective plastic films, and other supplies needed. They cost around $100 or less.
Research from UL's Firefighter Safety Research Institute (FRSI) shows that closing your bedroom door helps prevent a fire from spreading, lessens smoke damage and could even save lives. Just like having the right homeowners insurance, a little preparation can go a long way to help you rest easy.
It also significantly keeps carbon monoxide levels down. By limiting a fire's ability to spread, closing your bedroom door at night also gives you more time to react when the smoke alarm goes off. And these days, every second counts.
Keeping your bedroom door closed can help with noise reduction, privacy, and safety from potential intruders. On the other hand, keeping the door open can help with air circulation, temperature regulation, and monitoring of pets or children.