Heat Recovery Ventilation (HRV) for Irish Homes: How It Works & Why You Need It
Modern Irish homes are more airtight and better insulated than ever, which is great for energy bills, but it means stale, humid air has nowhere to go. A Heat Recovery Ventilation (HRV) system solves that: it constantly supplies fresh air while reclaiming heat from the outgoing stale air, keeping your home healthy and efficient.
How HRV Works
An HRV (also called MVHR-Mechanical Ventilation with Heat Recovery) is a whole-house, balanced ventilation system:
- Extracts stale, moist air from "wet" rooms (bathrooms, kitchens, utility rooms).
- Supplies filtered, fresh air to living rooms and bedrooms.
- Transfers heat from the outgoing air to the incoming air via a heat exchanger, so you don't throw warmth away.
- Utilises two small fans and ductwork to maintain quiet and efficient airflow.
Why Do We Need HRV?
- Airtight construction = mandatory ventilation strategy. Ireland's Building Regulations (Part F) require adequate, continuous ventilation in low-permeability homes; HRV is one of the approved ways to comply.
- Prevents condensation & mould. Without proper extraction, moisture builds up-leading to damp, mildew and even structural damage.
- Protects indoor air quality. Filters capture dust, pollen and other pollutants-better for allergy and asthma sufferers.
The Key Benefits of Heat Recovery
1. Constant Fresh, Filtered Air
Enjoy a steady supply of clean air throughout the year-no need to crack windows in January.
2. Lower Heating Bills
By reclaiming heat that would otherwise be dumped outside, HRV can trim heating demand - studies and field data show savings in the ~15% range (project-dependent).
3. Healthier Home Environment
Less condensation = less mould. Filters reduce pollen and dust-great news for anyone with respiratory issues.
4. Reduced Load on Your Heating System
Because incoming air is pre-warmed, your heat pump or boiler doesn't work as hard to maintain comfort.
5. No Draught Sensation
Balanced supply/extract means no cold draughts or "hole in the wall" vents.
Is HRV Right for Your Project?
- New builds aiming for A-rated performance or NZEB compliance? HRV is often the smartest choice.
- Deep retrofits and airtight renovations also benefit, provided duct routes can be planned.
- We'll assess air-tightness targets, room layout, and plant space to determine feasibility.
What We Need to Design Your System
Bring us:
- A set of your house plans (PDF or hard copy)
- Target airtightness levels (or your BER assessor's estimates)
- Any info on your heating system (e.g. heat pump, boiler) and hot-water strategy
We'll design HRV alongside your underfloor heating and heat pump sizing to ensure everything works as a coherent, efficient package. 061 413722 | PJ Matthews, Ballysimon Road, Limerick (Nationwide delivery)
FAQ - Heat Recovery Ventilation
Is an HRV system noisy?
A quality unit, correctly sized and installed, is very quiet-similar to a modern fridge. Proper duct sizing and acoustic lining keep sound levels low.
Will HRV heat my house?
No. HRV recovers heat from outgoing air to temper incoming air. It improves efficiency and comfort, but it isn't a primary heating system.
Can I retrofit an HRV in an existing home?
Yes, but it needs planning. We'll assess duct routes (attic spaces, service voids, stud walls) or consider decentralised units if full ducting isn't practical.
Do I still need separate extractor fans in bathrooms?
Usually not. In a whole-house HRV setup, bathrooms are extracted through the HRV ducts. Extra fans can upset the system's balance.
How often do I change the filters?
Typically, every 6-12 months, depending on local air quality and manufacturer guidance. It's a quick DIY job.
Will I feel draughts?
No. Balanced supply and extract airflow means no "cold blast" effect-just a steady supply of fresh, filtered air.
Does HRV work with heat pumps?
Absolutely. By reducing heat loss through ventilation, HRV lowers the load on any heating system, including heat pumps.