High Performance Building Systems - Air Quality

Building Healthy, Efficient Homes: Air Quality & Home Performance for New Construction and Remodeling

Imagine a home where the air is fresh, energy bills are low, and the structure stands strong against the elements for decades. This vision is achievable by prioritizing air quality and home performance in new home construction or remodeling projects. Air quality refers to the cleanliness and healthiness of indoor air, influenced by moisture, ventilation, and pollutants. Home performance measures how efficiently a home uses energy, depending on insulation, air sealing, and the building envelope.

Whether you're building from scratch or upgrading an older home, addressing challenges like moisture management, ventilation, air leakage, and energy loss is essential. In this blog, we’ll explore these challenges, offer practical solutions like the innovative LP Weatherlogic Air & Water Barrier system, and share effective insulation and air sealing strategies.

Challenges in Air Quality & Home Performance

Moisture Management

Excess moisture is a silent threat to homes, leading to mold, mildew, and structural damage. In humid climates, moisture infiltration can make homes sticky and prone to indoor air quality (IAQ) issues like mold growth. In drier climates, moisture imbalances can cause discomfort or health issues. For new construction, designing a building envelope that prevents water intrusion while allowing moisture vapor to escape is critical. For remodeling, addressing existing issues like poor drainage, leaky roofs, or inadequate vapor barriers is key. Without proper moisture management, both air quality and the home’s longevity suffer.

Ventilation

Proper ventilation ensures fresh air while controlling moisture and pollutants. In airtight homes, which are increasingly common for energy efficiency, natural ventilation may not suffice. Poor ventilation traps stale air, increasing the risk of IAQ issues, while excessive ventilation wastes energy. Mechanical ventilation systems are often necessary to balance air quality and energy efficiency, especially in tightly sealed homes.

Air Leakage

Uncontrolled air movement through gaps in the building envelope—around windows, doors, or electrical outlets—leads to energy loss, discomfort, and potential pollutant entry. According to the Whole Building Design Guide, air leakage can account for 10-42% of a home’s heating and cooling energy, depending on the climate. Reducing air leakage is essential for maintaining comfort and efficiency.

Energy Loss

Energy loss occurs when heated or cooled air escapes due to poor insulation or air leaks. This not only increases utility bills but also reduces comfort. Effective insulation and a tight building envelope are crucial to minimizing energy waste and create a sustainable home.

Solutions for Optimal Air Quality & Home Performance

Air Barriers: The Role of LP WeatherLogic

A robust air barrier is the backbone of a high-performing building envelope.  LP Weatherlogic Air & Water Barrier system is an innovative solution that combines structural sheathing with an integrated water-resistive overlay. At Ironhorse Designs, we only build high-performing building envelopes for our clients. Key features include:

• Dual Protection: Prevents air and water intrusion while allowing moisture vapor to escape, reducing the risk of mold and rot.

• Structural Integrity: Rated as Structural I sheathing, it provides strength and stiffness for walls and roofs.

• Ease of Installation: Installs like regular sheathing, saving time and labor costs while keeping job sites clean.

• Long-Term Durability: Backed by a 30-year limited warranty, ensuring lasting protection (LP Building Solutions).

• Sustainability: Qualifies as carbon negative, supporting eco-friendly building practices.

• Economical & Efficient: Reduces monthly utility bills on heating and cooling, along with allowing your existing HVAC system to not work as hard. On new homes, in some cases you may not need as large of units to heat and cool your home.

• Enhances Energy Efficiency: LP WeatherLogic eliminates the need for separate house wrap or roof underlayment in most cases, simplifying construction and enhancing energy efficiency.

Typical LP WeatherLogic Installation

Ventilation Systems: HRVs and ERVs

In airtight homes, mechanical ventilation is essential to maintain IAQ without sacrificing energy efficiency. Heat Recovery Ventilators (HRVs) and Energy Recovery Ventilators (ERVs) are ideal solutions:

• How They Work: These systems exchange stale indoor air with fresh outdoor air, recovering heat (HRVs) or both heat and humidity (ERVs) to minimize energy loss.

• Benefits: Ensure fresh air, control moisture, and reduce energy costs.

• Application: Ideal for both new construction and retrofits in older homes.

 Fully ducted HRV/ERV system. Credit: Fine Home Building

Effective Insulation Strategies

Insulation is critical for reducing energy loss and maintaining comfort. Effective strategies include:

• High-Performance Materials: Use spray foam for attics (R-value ~6 per inch) or rigid foam for walls (R-value ~4-5 per inch) for superior thermal resistance.

• Continuous Insulation: Avoid thermal bridges by ensuring insulation covers all areas without gaps.

• Hybrid Approaches: Combine materials like fiberglass batt (R-13) and spray foam for cost-effective, high-performance results.

6 Benefits of Hybrid Insulation Systems

1. Enhanced Thermal Performance: Northern Arizona’s weather can be unpredictable but hybrid insulation has your back. By combining different materials like fiberglass, cellulose, spray foam, or rigid foam boards, and achieving a higher overall R-value, hybrid insulation provides superior insulation, keeping your home warm in winter and cool in summer. This translates to reduced energy bills and comfortable living space year-round.

2. Moisture Control: Northern Arizona’s monsoons can bring high humidity and moisture challenges because of occasional rainstorms. Hybrid insulation incorporates materials with excellent moisture control properties, ensuring your home remains dry and free from potential issues like mold. This helps maintain a healthy and durable indoor environment, safeguarding your home’s integrity and the well-being of your family.

3. Air Sealing: Air gaps and drafts can make your HVAC system work harder. Hybrid insulation not only insulates, but also effectively seals gaps, cracks, and other sources of air infiltration. It prevents drafts, reduces heat transfer, and enhances the overall energy performance of your home. As a result, your home remains cozy with a maintained consistent temperature, and your energy bills stay in check while increasing the durability of your heating and cooling equipment.

4. Noise Reduction: If you’re looking for a quieter indoor space, hybrid insulation can help. With its sound-absorbing features, you’ll enjoy a more peaceful atmosphere, even in noisy surroundings.

5. Environmental Sustainability: Homeowners are increasingly seeking eco-friendly solutions. Hybrid insulation aligns with this goal by incorporating recycled or renewable materials. For example, cellulose insulation is made from recycled paper products, while spray foam insulation can be sourced from renewable plant-based materials. Opting for hybrid insulation means you are making a positive impact on the environment while enjoying energy savings.

6. Versatility: Hybrid insulation adapts to the unique requirements of homes with different building types and insulation needs. Whether you’re dealing with an older structure or a modern design, hybrid insulation can be customized to maximize energy efficiency and optimize insulation performance in various areas of your home, such as walls, attics, basements, and crawl spaces.

Air Sealing Methods

A tight building envelope requires meticulous air sealing. Common methods include:

• Caulking and Weatherstripping: Seal gaps around windows, doors, and outlets.

• Spray Foam: Use around penetrations like pipes and vents for airtight seals.

• LP WeatherLogic Seam & Flashing Tape: Ensures seamless connections in the air barrier system.

Testing airtightness with a blower door test is crucial to verify sealing effectiveness. This test uses a calibrated fan to create pressure differences, measuring air leakage in cubic feet per minute (CFM) or air changes per hour (ACH). For example, building codes may require an ACH of 3-5 at 50 Pascals for new homes (Energy.gov).

Illustration showing concept of a test. Credit: Elite Energy Concepts

Benefits of LP WeatherLogic

LP WeatherLogic stands out as a top choice for building envelopes due to its:

• Integrated Design: Combines air and water barriers with structural sheathing, reducing installation steps.

• Energy Efficiency: Creates a tighter envelope, minimizing air leakage and energy loss.

• Durability: Protects against water and air during construction and for decades after, backed by a 30-year warranty.

• Ease of Use: Installs like standard sheathing, saving time and labor.

• Sustainability: Carbon-negative properties align with green building goals.

Testing for Air Leakage

A blower door test is a critical tool for assessing a home’s airtightness:

• Process: A powerful fan is mounted in an exterior doorway to create a pressure difference (typically 50 Pascals). A manometer measures airflow, revealing leaks.

• Purpose: Identifies air leakage points, verifies sealing effectiveness, and ensures compliance with energy codes (e.g., 3-5 ACH in most climate zones).

• When to Use: At the end of new construction or before/after remodeling to measure improvements.

Typical Blower Door Setup. Credit: Elite Energy Concepts

Additional Best Practices

To further enhance air quality and home performance:

• Use Low-VOC Materials: Reduce indoor pollutants by choosing paints, adhesives, and finishes with low volatile organic compounds.

• Maintain HVAC Systems: Regular cleaning and filter replacement ensure optimal performance and air quality.

• Install Detectors: Carbon monoxide and radon detectors protect against unseen threats.

• Ensure Proper Drainage: Grade the foundation to direct water away, preventing moisture issues.

Conclusion

Creating a healthy, energy-efficient home requires careful attention to air quality and home performance. By addressing moisture management, ventilation, air leakage, and energy loss, you can build or remodel a home that’s comfortable, durable, and cost-effective. Systems like LP WeatherLogic, paired with smart insulation and air sealing strategies, make this goal achievable. Use blower door tests to verify your efforts and ensure compliance with energy standards.

Consult with professionals, such as energy auditors or Ironhorse Designs, to bring your vision to life. Start building or remodeling with confidence, knowing your home will be a haven for years to come. At Ironhorse Designs, we start from the foundation on all of our homes to build High Performance buildings that are not only beautiful, but energy efficient and healthy!

Citations

• Whole Building Design Guide - Air Barrier Systems

• LP Building Solutions - LP WeatherLogic

• Building Science Corporation - Understanding Air Barriers

• Energy.gov - Blower Door Tests

• Elite Energy Concepts - Air quality and energy conservation specialists

• Fine Home Building – Residential Remodel experts