Ventilation Questions & Answers – Based on Plumbavent.com
Ventilation Questions & Answers – Based on Plumbavent.com
FAQ is designed to help homeowners, installers, and developers understand the essentials of ventilation – all based on content from Plumbavent.com.
1. What factors go into designing a ventilation system?
Plumbavent analyses your building plans and engineering requirements to develop compliant, efficient ventilation solutions—drawings, BER-impact, and route planning included. See the Design Services
2. How is a duct layout visualized?
Through detailed 2D/3D schematic plans showing machine location, duct runs, manifolds, and room valves. Example plans are shown on the Design Services page
3. What makes S90 ducting install-friendly?
The S90 system uses click-together radial ducts with antibacterial, antistatic lining—and is rated SAP Appendix Q. Blog linked: 90 mm semi-rigid ventilation ducting
4. Are silencers included in duct solutions?
Yes—manifolds include built-in silencers (up to 45% noise reduction), plus optional attenuators for whisper-quiet performance.
5. What tools are required for install?
Basic tools only—ducts click together easily; installs can be completed single-handed. See Design Services and install guides
6. How is system cost broken down?
Cost estimate includes: design (~€480/£417), machine (~€2.5–3.4 k), ducting (~€2.6–3.2 k), install (€2.5–3.1 k), commissioning (~€380). See “How much does a ventilation system cost?
7. Why is machine over-sizing recommended?
Plumbavent specifies units 40–50% larger than required to ensure optimal performance and longevity.
8. Why include commissioning?
It ensures accurate airflow, quiet operation, and Building Control compliance via a performance certificate.
9. Which certifies the ducting system?
The S90 ducting is SAP Appendix Q-listed, confirming airtightness and compliance.
10. What are the 3 main ventilation options?
MVHR (“best for energy & control”), CMEV (economical extract-only), and Room/Wall units with heat recovery. See Ventilation made simple page
11. Can I improve ventilation in my home?
Yes you can and here is a solution to problems in the home due to ventilation.
12. What are the signs of poor ventilation
Condensation is the first sign of poor ventilation. If this persists and lingers on the glass this will give rise to mould growth and the release of spores into the air. You can see condensation on glass but it will also be on other surfaces that are not that easy to see. Any colder surface lower than 16 oC will promote mould growth.
You may find the air "stuffy" This is bad air and this is your body sensing this and telling you it needs fresher air.
When you awake in the morning and you fell “grotty” and slow to awake this is another tell tale sign.
13. What are the health risks of poor ventilation?
magine a classroom where children are bursting with energy, not from sugary snacks, but from the invigorating effects of fresh, clean air. Studies have shown that improved ventilation in schools leads to a significant boost in children's cognitive function and academic performance.
One study found that increasing ventilation rates in classrooms resulted in a 14% improvement in reading scores and a 10% increase in math scores. Additionally, children with improved air quality exhibited better concentration, reduced fatigue, and fewer respiratory issues.
This is especially crucial for children with asthma or allergies, who often suffer from exacerbated symptoms in poorly ventilated environments. By ensuring a constant supply of clean air, schools can create a healthier and more conducive learning environment for all students.
Investing in proper ventilation systems is not just about academic success, it's about laying the foundation for a healthy future. Clean air promotes better lung development, reduces the risk of chronic illnesses, and fosters a sense of well-being in children.
Therefore, prioritizing clean air ventilation in schools is not just a wise investment in education, but also a commitment to the long-term health and well-being of our future generation.
14: live longer with proper ventilation
With the correct ventilation in your home and workplace this will allow your body to manage the air quality as if it was using exterior air. Albeit the exterior air in some circumstances can be of poor quality modern ventilation systems can filter the incoming air to remove some pollutants. The air your body needs is a consumable as is water and food. We are careful with consumption of the water and foods as we can see, feel, touch and taste the quality. Air is somewhat different as we cant determine the quality until it is exceptionally bad for us. The human body has not developed this skill as it was never required in our development. But as the human race has developed at an exceptional speed and pollution with air quality has deteriorated we have to assist the body with an proactive approach to the air we allow into our bodies.
15: How do I ventilate a room with a lot of moisture, like a bathroom or laundry room?
The best way is to install a single room heat recovery unit
What is ventilation and why is it essential?
Ventilation is the controlled replacement of indoor air with fresh outdoor air. It reduces humidity, CO₂ buildup, and pollutants—protecting health and property. In well-sealed homes, natural air exchange is limited, so ventilation is crucial for indoor air quality and condensation control.
Read more:
How does MVHR differ from natural or trickle ventilation?
MVHR (Mechanical Ventilation with Heat Recovery) exchanges air while reclaiming up to 96% of heat, unlike trickle vents which just allow outdoor air in passively. MVHR provides consistent, energy-efficient ventilation and is ideal for airtight homes.
Compare systems: https://plumbavent.com/blogs/news/best-ventilation-system
When should I choose CMEV over MVHR?
CMEV (Continuous Mechanical Extract Ventilation) continuously removes air from wet rooms without recovering heat. It's cheaper and simpler than MVHR, making it a practical option for homes where full heat recovery isn’t a priority or budget is limited.
See CMEV advantages: https://plumbavent.com/blogs/news/ventilation-compliance
Can room-based (decentralised) systems replace full MVHR?
Yes, decentralised MVHR (dMVHR) units are great for apartments or retrofits. Each unit serves one or two rooms with individual heat recovery, requiring no ducting. Multiple units can be used for whole-home ventilation in constrained spaces.
Explore dMVHR options: https://plumbavent.com/collections/decentralised-mvhr
What is Positive Input Ventilation (PIV)?
PIV draws filtered air from lofts into your home to dilute moisture and pollutants. It’s affordable and simple to install, but it doesn't recover heat or control air direction like MVHR. It works best in older or leaky homes.
Learn about PIV systems:
How does an MVHR heat exchanger work?
An MVHR heat exchanger transfers warmth from outgoing stale air to incoming fresh air without mixing the two. This retains up to 96% of heat, reducing heating bills and maintaining comfort year-round.
How MVHR works: https://plumbavent.com/blogs/news/best-ventilation-system
What does ‘balanced’ ventilation mean?
Balanced ventilation means the supply of fresh air matches the extraction of stale air, creating neutral pressure. This prevents draughts, condensation, or indoor pollutants from accumulating—ensuring comfort and consistent air quality. It basically means the air that tis being pumped in is equal to the air being extracted. This prevent air from the fabric of the building effected with the internal air.
More on balanced systems: https://plumbavent.com/blogs/news/ventilation-compliance
What heat recovery efficiencies can I expect?
High-quality MVHR systems, like those from Genvex, recover 90–96% of heat from outgoing air. This keeps rooms warm, lowers heating bills, and maintains excellent indoor air even in winter.
View Genvex MVHR range: https://plumbavent.com/collections/mvhr-machines
What is bypass mode in summer?
Bypass mode prevents overheating by routing cool outdoor air directly indoors, skipping the heat exchanger. It’s ideal for hot days or nights when you want airflow without added warmth. Using the outdoor air to cool the indoor air is known as passive cooling.
Options https://plumbavent.com/blogs/news/best-ventilation-system
Why use 90 mm ducting in MVHR systems?
Plumbavent’s S90 semi-rigid 90 mm ducting matches metal duct performance while being flexible, quiet, and easy to install. It offers low air resistance and acoustic benefits, making it ideal for high-efficiency ventilation setups.
Explore
Is semi-rigid ducting easy to install?
Yes! S90 semi-rigid ducting is lightweight, flexible, and designed for hassle-free installation. It bends around corners, clips into place, and connects with simple fittings. It’s perfect for new builds or retrofits, whether installed by DIYers or professionals.
More information
What standards does S90 ducting meet?
S90 ducting is SAP Appendix Q and BRE-approved, meaning it performs as well as metal ducting. It meets EN 13180 for hygiene and airflow. This ensures reliable, airtight, and efficient performance—ideal for homes targeting energy ratings like BER or Passivhaus.
Learn about S90 performance and cost
How do I design a ventilation system for a house?
Start with a floor plan, room types, and desired machine location. Plumbavent offers a full MVHR design service to calculate airflow rates, layout ducting, and ensure Building Regulations compliance. This optimizes performance, comfort, and energy savings.
Request a system design: https://plumbavent.com/products/system-design
Can I install it myself?
Yes. With clear instructions and colour-coded kits, S90 ducting is ideal for self-install. You’ll still need a certified technician to commission the system, but most of the physical work—duct routing, clipping, and fitting—can be DIYed.
See installation resources: https://plumbavent.com/pages/install
What factors determine ventilation layout?
Duct routing depends on building size, room function, and machine location. Bedrooms need fresh supply air; wet rooms need extraction. Minimising duct length, avoiding tight bends, and separating noisy areas from sleeping zones improves efficiency and comfort.
More layout tips: https://plumbavent.com/blogs/news/ventilation-ducting-cost
What fittings are needed for S90 ducting?
You'll need S90 connectors, clips, vaned bends, manifolds, and plenums to create a fully airtight and efficient system. These fittings are designed for tool-free assembly and low resistance, helping systems perform like rigid metal ductwork without the complexity.
Shop S90 fittings: https://plumbavent.com/collections/s90-ducting
What’s special about S90 bends/connectors?
S90 bends include internal flow vanes that gently guide air around corners, reducing turbulence and noise. These vanes maintain static pressure and efficiency—mimicking commercial metal ducting in a compact, user-friendly format.
Learn about vaned fittings: https://plumbavent.com/products/s90-duct-connector-bend
What are manifolds and plenums for?
Manifolds split airflows from the central unit into multiple duct runs, while plenums connect the machine to these manifolds. They ensure balanced airflow, reduce noise, and simplify commissioning by making each room adjustable.
See plenum and manifold kits: https://plumbavent.com/collections/s90-ducting
Which MVHR machines do Plumbavent offer?
Plumbavent supplies Genvex MVHR systems—renowned for efficiency, durability, and quiet performance. These machines offer advanced heat recovery, summer bypass, and smart controls, and are backed by decades of use across Ireland and the UK.
Browse MVHR machines: https://plumbavent.com/collections/mvhr-machines