Insulation & Ventilation Terms
A Quick Overview On The Common Terms You'll Here In This Industry
Table of Content
Insulation Terms:
Aerogel Insulation
An ultra-light, highly insulating material made from gel where the liquid component has been replaced with gas. It offers exceptional thermal performance with minimal thickness, making it useful for space-constrained applications. However, its high cost limits widespread use in building construction.
Air Infiltration
Uncontrolled air leakage into a building through cracks and openings. It can significantly impact energy efficiency and indoor air quality. Proper air sealing is essential for effective insulation and ventilation strategies.
Air Sealing
The process of identifying and sealing air leaks in a building's envelope to reduce uncontrolled air movement. Common areas include windows, doors, electrical outlets, and where different building materials meet. Crucial for reducing energy consumption and managing moisture.
Batt Insulation
Pre-cut panels of insulation made from fiberglass or mineral wool, sized to fit between wall studs or roof rafters. Easy to install but gaps can be left if not fitted properly. Commonly used in residential construction for walls, attics, and floors.
Blown-in Insulation
Loose-fill insulation that's blown into wall cavities or attic spaces using special equipment. Materials involve cellulose, fiberglass, or mineral wool. Provides excellent coverage and can fill irregular spaces, making it ideal for retrofitting existing homes.
Cellulose insulation
An eco-friendly option installed as loose-fill, made from recycled paper products treated with fire-retardant chemicals like boric acid. It offers superior density and coverage compared to fiberglass, with R-values of R-3.2 to R-3.8 per inch, effectively diminishing air infiltration and enhancing sound dampening.
Cementitious Foam
A lightweight, fire-resistant insulation material made by mixing cement with a foaming agent. It can be sprayed or poured in place, providing both insulation and structural support. It offers unique benefits in certain applications, even though it is not as thermally efficient as some other choices.
Cotton Insulation
Made from recycled denim and cotton fibers, this eco-friendly insulation option is treated with borate for fire and pest resistance. It offers similar R-values to fiberglass batts and is less irritating to install. However, it can be more expensive and may absorb moisture more readily than synthetic options.
Dew Point (Temperature)
The temperature at which air reaches saturation and water vapor starts to condense into liquid water. In basements, this can lead to condensation on walls and surfaces, especially where temperature differences occur.
Dynamic Insulation
A system where air is drawn through permeable insulation material before entering a building, pre-warming (or cooling) the air and increasing effective R-value. It combines insulation and ventilation functions but requires careful design to balance air flow and avoid moisture issues.
Eco-Friendly Insulation
Made from renewable or recycled materials such as sheep's wool, cork, cotton, and recycled denim. These sustainable options provide comparable thermal performance to traditional insulation while offering unique benefits, including low embodied energy, natural moisture regulation, and reduced chemical exposure for installers and occupants.
Fenestration
Openings in a building’s structure, such as windows, doors, and skylights. Proper fenestration design balances natural light, ventilation, and energy efficiency, impacting both insulation and ventilation performance.
Fiberglass insulation
A well-known and cost-effective material made from fine glass fibers. It is available in batt and blown-in forms, offering R-values of R-2.9 to R-3.8 per inch along with fire resistance. Even though it provides excellent thermal and acoustic insulation, proper protective gear is essential during installation to prevent skin and respiratory irritation.
Foam Board Insulation
Composed of rigid panels made from expanded polystyrene (EPS), extruded polystyrene (XPS), and polyisocyanurate (polyiso), providing high R-values of R-4 to R-6.5 per inch and great moisture resistance. It is commonly used in space-saving applications like continuous insulation, foundation walls, and roofing systems.
Gas-Filled Panels
Insulation panels containing low-conductivity gases like argon or krypton, sealed within thin polymer films. They can provide high R-values in thin profiles, making them useful for retrofitting or space-constrained applications. However, cost and limited availability restrict widespread use.
Hemp Insulation
A natural, renewable type of insulation made from hemp fibers. It offers good thermal and acoustic properties, is moisture-resistant, and can regulate humidity. Hemp insulation is biodegradable and environmentally friendly, but may be more expensive than traditional options.
Humidity, Relative
The proportion of water vapor in the air relative to the maximum it can hold at a specific temperature, shown as a percentage. Warmer air can hold more moisture, so increasing temperature while keeping the vapor constant reduces relative humidity.
Hybrid Insulation Systems
In order to enhance performance and cost-effectiveness, these systems combine multiple insulation types, such as spray foam with fiberglass batts or foam board with blown-in cellulose. By leveraging the strengths of different materials, these systems optimize thermal performance, moisture control, and air sealing while maintaining manageable installation costs.
Insulated Concrete Forms (ICFs)
Interlocking modular units made of insulating foam that are stacked to form walls and then filled with concrete. ICFs provide continuous insulation, excellent air sealing, and structural strength. They offer high R-values and good sound insulation but require specialized construction techniques.
Loose-Fill Cellulose
An insulation material made from recycled paper products, treated with fire retardants. It is blown into wall cavities or attic spaces, conforming to irregular shapes and providing good coverage. Cellulose has a higher R-value per inch than fiberglass and can help reduce sound transmission.
Mineral Wool (Rockwool)
Insulation made from recycled slag or natural rock, spun into fibers. It offers good thermal and acoustic insulation, fire resistance, and moisture control. Mineral wool is non-combustible, making it suitable for use as a firestop in wall assemblies.
Mycelium Insulation
An experimental, biodegradable insulation material grown from fungal mycelium and agricultural waste. It offers promising thermal and acoustic properties, fire resistance, and is fully compostable. Still in development, it represents a potential future direction for sustainable insulation solutions.
Nano Insulation Materials (NIMs)
Emerging insulation technologies that utilize nanostructures to achieve very low thermal conductivity. These could potentially offer superior insulation performance in thin layers, but are still largely in the research and development phase for building applications.
Passive House (Passivhaus)
An ultra-low energy building standard that emphasizes superinsulation, airtightness, high-performance windows, ventilation with heat recovery, and minimal thermal bridging. It results in buildings that require very little energy for heating and cooling.
Permeability
A material's capacity to allow moisture to pass through it, with higher permeability indicating easier transmission. This property is crucial in selecting appropriate building elements and vapor barriers for different climate zones and building applications.
Phase Change Materials (PCMs)
Substances that absorb or release heat as they change between solid and liquid states at room temperature. When incorporated into building materials or insulation, PCMs can help regulate indoor temperatures, reducing heating and cooling loads.
Phenolic Foam
A high-performance rigid insulation board with one of the highest R-values per inch among commonly available options. Its closed-cell structure provides good moisture resistance and fire performance. Although effective, it is less common due to higher cost compared to other foam insulations.
Polyurethane Insulation
Available in spray and board forms, recognizable for its high R-value per inch (R-5.5 to R-6.5) and excellent air-sealing capabilities. Spray polyurethane foam expands to fill cavities and form an effective air barrier, with open-cell (lower density) and closed-cell (higher density) varieties, the latter offering better moisture resistance.
Radiant Barrier
A reflective material, usually aluminum foil, used to reduce radiant heat transfer in buildings. Commonly installed in attics to reflect solar heat, it can improve energy efficiency, especially in hot climates. Effectiveness depends on proper installation and climate conditions.
Reflective Insulation
Products with highly reflective surfaces, like foil-faced kraft paper or plastic film, designed to reduce radiant heat transfer. Most effective when facing an air space, it is commonly used in attics and walls. Performance varies with installation method and climate conditions.
Rigid Foam Insulation
Plastic foam boards used for insulating walls, roofs, and foundations. Popular varieties include polyisocyanurate (polyiso), extruded polystyrene (XPS), and expanded polystyrene (EPS). They offer high R-values per inch and can act as air barriers, but proper installation is crucial to prevent moisture issues.
R-Value
A metric of thermal resistance that reflects how well a material resists heat flow. The higher the R-values the better the insulation performance. It is used to assess and compare the insulation efficiency of various materials and thicknesses.
Smart Insulation
Adaptive insulation systems that can change their thermal properties in response to environmental conditions or user inputs. This could include solutions that become more or less insulating based on temperature, or electrically controlled systems. Mostly theoretical, with some prototypes in development.
Spray Foam Insulation
A chemical-based insulation that expands upon application to fill gaps and create an air barrier. Available in open-cell (less dense, more permeable) and closed-cell (denser, more moisture-resistant) varieties. Offers high R-value per inch and excellent air sealing properties.
Structural Insulated Panels (SIPs)
Prefabricated insulation systems consisting of an insulating foam core sandwiched between two structural boards, typically oriented strand board (OSB). SIPs provide excellent insulation and air sealing while speeding up construction time, but require careful design for electrical and plumbing integration.
Thermal Bridge
Areas in the building envelope where heat flows more easily, often due to conductive materials penetrating insulation. Common in metal framing, window frames, and balconies. Reducing thermal bridges improves overall insulation performance.
Thermal Mass
Materials with high heat capacity that can absorb, store, and release heat energy. Examples include concrete, brick, and water. Proper use of thermal mass can help regulate indoor temperatures and reduce heating and cooling loads.
Thermally Broken Studs
Framing members designed to reduce thermal bridging in wall assemblies. They typically consist of wood or metal studs with an integrated insulating layer. This design significantly improves the overall thermal performance of insulated wall systems.
U-Value (Factor)
The rate of heat transfer through a material, inverse to R-value. Lower U-values designate better insulation. It is commonly used for windows and doors to describe their total thermal efficiency, including frames and glazing.
Vacuum Insulated Panels (VIPs)
High-performance insulation panels consisting of a porous core material encased in an airtight envelope and evacuated of air. They offer extremely high R-values per inch but are expensive and can lose effectiveness if punctured. Primarily used in specialized applications with strict space limitations.
Vapor Barrier
A material that significantly reduces vapor transmission, typically with a permeance rating of 0.1 perms or less. Used to prevent water vapor from migrating into building assemblies, but proper placement is crucial to avoid trapping moisture.
Vapor Diffusion
The movement of water vapor through materials due to vapor pressure differences. Understanding this process is essential for proper moisture management in building design and for selecting appropriate insulation and vapor control strategies.
Vapor Drive
The flow of water vapor through building materials caused by differences in vapor pressure. It can occur from heated interiors in winter or from solar-heated exteriors in summer, potentially leading to moisture issues within walls or other building components.
Vapor Retarder
Materials that restrict water vapor flow, with varying levels of permeance: Class I (≤0.1 perms), Class II (0.1-1.0 perms), and Class III (1.0-10 perms). Their use varies by climate and wall assembly design to manage moisture effectively.
Vapor Barrier
A material that significantly reduces vapor transmission, typically with a permeance rating of 0.1 perms or less. Used to prevent water vapor from migrating into building assemblies, but proper placement is crucial to avoid trapping moisture.
Ventilation Terms:
Air Changes per Hour (ACH) / Air Exchange Rate
A measure of how often the air in a space is completely replaced within an hour. It quantifies ventilation performance for both natural and mechanical systems. Higher rates indicate better ventilation, essential for areas with high pollutant loads or occupant density, though they may increase energy costs.
Attic Fan
A powered ventilation device installed in the attic to expel hot air, decreasing heat buildup and potentially lowering cooling costs. It can be thermostatically controlled to work when attic temperatures reach a certain level, but proper sizing and balancing with intake vents are crucial for effectiveness.
Balanced Ventilation
A system combining both supply and exhaust fans to provide fresh air intake and stale air removal at equal rates. This approach maintains neutral pressure in the building, reducing issues associated with positive or negative pressurization, but typically requires more equipment and careful design.
Blower Door Test
A testing method designed to assess a building's level of airtightness. It involves using a powerful fan to depressurize the building, allowing technicians to detect and measure air leaks. This test helps pinpoint areas needing improved insulation or air sealing.
Chimney Effect (Stack Effect)
A natural ventilation phenomenon where the differences of temperature between indoor and outdoor air drive vertical air movement in buildings. As warm air rises and exits through upper levels, it forms negative pressure that pulls in cooler air at lower levels, a process especially impactful in tall buildings and crucial for heating, cooling, and ventilation methods.
Continuous Mechanical Ventilation
A system that uses fans and ductwork to provide 24/7 fresh air exchange by replacing stale air with fresh outdoor air. Often equipped with filters to remove contaminants, this system may also involve heat recovery features to reduce energy loss while maintaining effective ventilation.
Cross Ventilation
A natural ventilation strategy that involves creating airflow across an interior space by placing openings on opposite sides of a room or building. Effective for cooling and fresh air exchange, especially in mild climates. The design considers prevailing wind directions for optimal performance.
Demand-Controlled Ventilation
An intelligent ventilation system that modulates airflow according to occupancy or indoor air quality metrics such as CO2 levels. It ensures adequate fresh air supply while minimizing energy waste from over-ventilation, making it particularly useful in spaces with variable occupancy.
Displacement Ventilation
A stratified air distribution method that supplies cool air at low velocity near the floor, which then rises as it warms, displacing warmer, contaminated air upwards. This approach can improve air quality and energy efficiency in large spaces like auditoriums or industrial facilities.
Earth Tube
A passive cooling and ventilation system that draws outdoor air through underground pipes, where it is cooled by the earth's relatively stable temperature before entering the building. It can provide pre-cooled air in summer and pre-warmed air in winter, reducing HVAC loads.
Energy Recovery Ventilator (ERV)
Similar to an HRV, but also transfers moisture between incoming and outgoing air streams. ERVs are particularly useful in humid climates as they help maintain indoor humidity levels while providing fresh air and conserving energy.
Exhaust Ventilation
A system that uses fans to expel stale indoor air, creating negative pressure that draws in fresh air through intentional openings or leaks. Commonly used in bathrooms and kitchens, it is simple but can lead to uncontrolled air infiltration and potential backdrafting of combustion appliances if not properly designed.
Heat Recovery Ventilator (HRV)
A mechanical ventilation device that recovers heat from exhaust air to pre-warm incoming fresh air. It improves energy efficiency while providing controlled ventilation, especially useful in well-insulated, airtight buildings.
Hybrid Ventilation System
The integration of natural and mechanical ventilation strategies used to strengthen energy efficiency and sustain optimal indoor air quality. By automatically switching between natural ventilation during optimal outdoor conditions and mechanical ventilation in extreme weather or poor air quality, these systems often merge heat recovery and smart controls for optimized functionality.
Makeup Air System
A powered ventilation system that supplies fresh outdoor air to replace air removed by exhaust systems, maintaining building pressure balance. It is crucial in commercial kitchens and industrial settings with high-volume exhaust to prevent backdrafting and ensure proper equipment operation.
Mixed-Mode Ventilation
A combined natural-mechanical ventilation solution often controlled by a building management system. It maximizes the use of natural ventilation when outdoor conditions are favorable, switching to mechanical systems when necessary, and optimizing energy efficiency and comfort.
Night Purge Ventilation
A strategy that uses cool nighttime air to flush out heat accumulated in a building's thermal mass during the day. It is particularly effective in climates with significant diurnal temperature swings, reducing daytime cooling loads and improving overall energy efficiency.
Passive Ventilation
A method of ventilating a building without mechanical systems, relying instead on natural forces like wind and thermal buoyancy. Utilizes strategically placed openings to create air movement. Can include elements like stack ventilation, cross ventilation, and solar chimneys.
Plenum
An air distribution box or chamber that's part of an HVAC system, used to equalize air pressure and distribute air to multiple outlets. In ventilation systems, plenums can help balance airflow and reduce noise from air movement.
Pressure Differential Ventilation
The formation of controlled air movement by creating pressure differences between building zones, either positive (pushing air out) or negative (drawing air in). This method is commonly implemented in environments like cleanrooms, hospitals, and industrial facilities to maintain airflow and avert cross-contamination between spaces.
Ridge Vent
A type of roof vent installed at the peak of a sloped roof. It enables the release of hot air and moisture from the attic area. When used with soffit vents, it creates a natural convection loop, improving attic ventilation and helping to regulate temperature and moisture levels.
Smart Ventilation Systems
The utilization of sensors, automation, and IoT connectivity to enhance air exchange by monitoring real-time factors such as CO2 levels, humidity, temperature, and occupancy. They often include smartphone controls, scheduling options, and integration with building management systems for maximized efficiency and comfort.
Soffit Vents
Openings installed under the eaves of a roof that allow outside air to enter the attic space. Part of a properly ventilated attic system, they work in conjunction with ridge or roof vents to create natural air circulation, reducing heat buildup and moisture issues.
Solar Chimney
A passive ventilation feature that uses solar energy to create a natural updraft, drawing air through a building. It consists of a vertical shaft painted black or glazed to absorb solar radiation, heating the air inside and causing it to rise, which induces air movement throughout the structure.
Stack Effect
The movement of air in a building due to temperature differences between the interior and exterior. Warm air rises and escapes from upper levels, drawing in cooler air at lower levels. It affects ventilation patterns and energy efficiency.
Supply Ventilation
A mechanical system that uses fans to bring fresh outdoor air into a building, creating positive pressure that pushes stale air out through leaks or designated exhaust points. It allows for better control of incoming air quality but may increase heating and cooling costs in extreme climates.
Trickle Vents
Compact, adjustable vents usually fitted in window frames or walls to offer steady background ventilation. They allow for controlled air exchange without the need to open windows, helping to reduce condensation and maintain indoor air quality while minimizing heat loss.
Ventilation (Building)
The process of exchanging indoor and outdoor air to maintain air quality and manage moisture levels. It can be natural (through openings) or mechanical (using fans and ducts), and is crucial for occupant health and building durability.
Ventilation Effectiveness
A measure of how efficiently a ventilation system distributes fresh air throughout a space and removes contaminants. It considers factors like air distribution patterns, short-circuiting, and dead zones. Higher effectiveness means better indoor air quality with less overall air exchange.
Ventilation Heat Loss
The energy lost when warm indoor air is replaced with cooler outdoor air through ventilation. While necessary for air quality, it can significantly impact heating costs. Strategies like heat recovery ventilation and demand-controlled ventilation can help mitigate this loss.
Whole-House Fan
A large fan typically installed in a central hallway ceiling that draws cool outdoor air in through open windows and exhausts hot indoor air into the attic and out through attic vents. It is an energy-efficient cooling option for mild climates or during transitional seasons.
Wind Catcher
A traditional architectural feature for natural ventilation, particularly in hot, arid climates. It consists of a tower with openings facing prevailing winds, catching and directing cool air down into the building while allowing hot air to escape through other openings.
Insulation Terms:Aerogel InsulationAir InfiltrationAir SealingBatt InsulationBlown-in InsulationCellulose insulationCementitious FoamCotton InsulationDew Point (Temperature)Dynamic InsulationEco-Friendly InsulationFenestrationFiberglass insulation:Foam Board InsulationGas-Filled PanelsHemp InsulationHumidity, RelativeHybrid Insulation SystemsInsulated Concrete Forms (ICFs)Loose-Fill CelluloseMineral Wool (Rockwool)Mycelium InsulationNano Insulation Materials (NIMs)Passive House (Passivhaus)PermeabilityPhase Change Materials (PCMs)Phenolic FoamPolyurethane InsulationRadiant BarrierReflective InsulationRigid Foam InsulationR-ValueSmart InsulationSpray Foam InsulationStructural Insulated Panels (SIPs)Thermal BridgeThermal MassThermally Broken StudsU-Value (Factor)Vacuum Insulated Panels (VIPs)Vapor BarrierVapor DiffusionVapor DriveVapor RetarderVapor BarrierVentilation terms:Air Changes per Hour (ACH) / Air Exchange RateAttic FanBalanced VentilationBlower Door TestChimney Effect (Stack Effect)Continuous Mechanical VentilationCross VentilationDemand-Controlled VentilationDisplacement VentilationEarth TubeEnergy Recovery Ventilator (ERV)Exhaust VentilationHeat Recovery Ventilator (HRV)Hybrid Ventilation SystemMakeup Air SystemMixed-Mode VentilationNight Purge VentilationPassive VentilationPlenumPressure Differential VentilationRidge VentSmart Ventilation SystemsSoffit VentsSolar ChimneyStack EffectSupply VentilationTrickle VentsVentilation (Building)Ventilation EffectivenessVentilation Heat LossWhole-House FanWind Catcher
Green Attic Insulation Customer Reviews
.png){kind=avatar}
8 days ago
Romuno and his team came on time and were very cordial and friendly. They discovered
an issue with some electrical work while working on the insulation, which I was surprised and happy about, and were able to rectify the situation easily and at a great value, considering the timing of the project, etc. Romuno made it clear he want to ensure my satisfaction throughout the process. When finished, the job site was cleaned very well.
I highly recommend this company and all its team members and hope to do more projects in the future with them!
Read more
Posted on
Google
8 days ago
Romulo and his teammate were so fast and clean at insulating and repairing our damaged
ceiling due to a roof leak. Again it was easy to engage green Attic as a return customer because I felt well treated with their work when they first insulated and managed.to transform our cold home. Great job!
Read morePosted on
Google
22 days ago
Fantastic work. No nonsense, clean job site, speedy and good communication.
an issue with some electrical work while working on the insulation, which I was surprised and happy about, and were able to rectify the situation easily and at a great value, considering the timing of the project, etc. Romuno made it clear he want to ensure my satisfaction throughout the process. When finished, the job site was cleaned very well.
I highly recommend this company and all its team members and hope to do more projects in the future with them!
Posted on
Google
1 month ago
Had our attic insulation beefed up with new blown in cellulose. Was a major improvement
immediatly after it was installed. Cut our heating needs by 3x to maintain temperature in the house.Team working on my house was friendly and professional. Team leads Romulo and Omar did a great job making sure everything was done right and everything was cleaned up after.
Read morePosted on
Google
2 months ago
Romulo & Alvaro did a great job installing everything. Cindy, Frank and the Green Attic team
were extremely attentive. I love how easy they made the process, everything is online even the rebates.
BONUS: I originally reached out to them to check for mold free of charge.
Read morePosted on
Google
2 months ago
These guys did a great job! Great price, quality service, and they offer several payment
options and plans. I thought we bought a lemon of a house and the insulation and sealing job they did fixed all of our issues and were so thrilled! Highly recommend these guys. Plus they are local so it’s great supporting a chicago based company.
Read morePosted on
Google
3 months ago
Highly recommend Green Attic. Scheduled to have my attic re-insulated and Romulo
and his crew did a fabulous job. The attic was in pretty bad shape prior to the work getting done and green attic made it look so good. The crew worked efficiently and got the job done in 2 days. I also asked Romulo to install a couple other things on my roof outside of the scheduled project and he very kindly and willingly did so without hesitation. Very pleased with how everything turned out. Thank you so much for a job well done! Before and after pics below.
Read morePosted on
Google
