A lot of people still think you have to sacrifice comfort to improve energy efficiency. But that’s so 1970s energy crisis. As we face the prospect of peak oil and increasingly volatile energy markets, we don’t have to face shivering in the cold and sweating in the heat.
All it takes is some basic building science and the use of advanced building envelope solutions to enhance occupant comfort and reduce energy efficiency at the same time. Here are six simple rules for a happy relationship between occupant comfort and energy bills.
Rule #1: forget Grandad’s insulation. High performance, plastic based insulation materials offer better thermal performance than traditional materials. With R-values ranging from 3.5 per inch for expandable polystyrene (EPS) up to 6.7 per inch for closed-cell, spray-applied polyurethane foam (SPF), these materials also eliminate thermal bridging and convection looping (when properly installed). That gives you an installed performance level that’s much closer to the lab results you think you’re buying when you read the rated R-value. New graphite-enhanced EPS uses tiny flecks of graphite as reflectors to improve thermal performance by 20% over traditional EPS—allowing you to reach higher insulation levels, or attain the same levels with less material.
Rule #2: control air migration. We pay a lot of money to condition interior air, so why do we let up to 40% of it escape an average building? Build tight and ventilate right by including a continuous air/weather barrier and providing mechanical ventilation for fresh air. Not only will you be able to reduce HVAC needs at the design phase (or take pressure off existing systems), but you’ll improve indoor air quality by reducing the risk of mold from moisture vapor transmission and condensation in the wall cavity. And those pesky, comfort robbing drafts? Gone.
Rule #3: think beyond sticks. Wall technologies like structural insulated panels (SIPs), insulating concrete forms (ICFs) and exterior insulated finishing systems (EIFS) combine high insulation levels—as much as R-50 for a vertical wall—with air leakage control and structural strength. Not only are occupants comfortable in their day-to-day living inside the structure, they have added comfort knowing the building is going to last.
Rule #4: don’t blow your top. For low-slope roofs, SPF roofing systems can save so much energy they pay for themselves in an average of 4.5 years. Combine them with reflective roof coatings and they also lower rooftop temperatures, urban heat island effect and smog. That means you can be more comfortable outside, too.
Rule #5: don’t forget the weak link. Usually, windows and doors are the problem spot in a building envelope designed to save energy and increase comfort. But windows with warm-edge thermoplastic spacer (TPS) technology act as a thermal break to reduce heat transfer between conductive materials and seal the edges of gas-filled insulated glazing units. The result? An energy performance improvement of 10%.
Rule #6: keep an eye on future developments. R&D efforts are producing some revolutionary emerging technologies—some of them available now. Try phase change material for interior wall board that can convert mass walls into massive walls. Tiny wax capsules absorb and release thermal energy in a controlled manner, enhancing comfort and dampening temperature swings. Modeling results show energy used for air conditioning can be reduced by up to 33%. Another new technology available today is near-infrared (NIR) reflective pigments that provide aesthetic color choice freedom and the same benefits as a white coating. Coming soon: vacuum insulated panels (VIPs) and nanofoam insulation materials are expected to completely change the way we think about creating energy efficient buildings in the future.
Learn more about ways you can get comfortable with your energy bill.