Passive House Seminar for the Professionals from the Building Sector

Passive House Seminar for Professionals from the Building Sector DAY 2

Design – Ventilation systems

Passive House Seminar for Professionals from the Building Sector Day 1 What is a Passive House? Design According to the Passive House Criteria Design – Heating Systems and Energy Supply Design – Solar Energy Utilization Planning and Concept Development Realization and Construction Processes Basic educational course about Passive Houses, organised by a local partner in the European funded PASS-NET project Passive House Seminar for Professionals from the Building Sector Day 2 Design –Ventilation systems Day 2 Planning and Calculations – introduction to PHPP Energy Statistics, Standards and Certifications Design – Air tightness Design – Ventilation systems Design – Windows Regional examples of built Passive Houses

Passive House Seminar for Professionals from the Building Sector Main purpose of ventilation systems Remove polluted air –CO 2 –Pollutants, particles –Moisture Supply fresh air –Heating –Cooling Picture: Ulla Janson Day 2 Design - ventilation systems Good ventilation is important for both our health and for the sustainability of the building Indicators of insufficient and inadequate ventilation may be:  Condensation on the internal window glass pane during winter  A perception of the air as being stuffy or ”heavy"  Lingering condensation on bathroom mirrors after showers and baths

Day 2 Design - windows Passive House Seminar for Professionals from the Building Sector Principles of ventilation  Natural ventilation –In buildings with natural ventilation there is no mechanical fan. The air is let in by leakages and planned air slits and is exhausted in exhaust air pipes, often placed in the chimney stack. Picture: The Swedish Energy Agency

Day 2 Design - windows Passive House Seminar for Professionals from the Building Sector Principles of ventilation  Exhaust air ventilation –In the exhaust air ventilation system a mechanical fan is always running, creating an under pressure in the house. The supplied air is let in by leakages and planned air slits. Picture: The Swedish Energy Agency

Day 2 Design - windows Passive House Seminar for Professionals from the Building Sector Principles of ventilation Picture: The Swedish Energy Agency  Mechanical ventilation –Balanced ventilation – air flows in and out from the building are equal

Day 2 Design - windows Passive House Seminar for Professionals from the Building Sector Principles of ventilation Picture: The Swedish Energy Agency  Mechanical ventilation - Supply and exhaust air ventilation with heat exchanger –An easy way to save a lot of energy for heating purposes in buildings –Heat exchangers in passive houses have an efficiency of 80-85% 1. Supply air 2. The cold supply air is heated in a heat exchanger by the warm exhaust air 3. Heated supply air is let in to the house 4. The used exhaust air goes from the kitchen and bathroom 5. The exhaust air is getting cold in the heat exchanger and is let out

Day 2 Design - windows Passive House Seminar for Professionals from the Building Sector Heat recovery  Rotary heat exchanger  Counter-flow plate heat exchanger –Most efficient heat recovery –Might also recover odours –Efficient heat recovery –No odours are transmitted Picture: Swegon

Day 2 Design - windows Passive House Seminar for Professionals from the Building Sector Specific Fan Power - SFP  Measures how efficient a fan uses the electricity needed to move maximum amounts of air  SFP = P tot /V max (kW/(m 3 /s))  SFP – values for air-to-air heat exchanger units –SFP 1.5Very efficient –SFP 2.0Efficient –SFP 2.5Less efficient –SFP 4.0Waste of a high quality energy source Example: An air-to-air heat exchanger with a supply air fan which uses 10 kW and an exhaust air fan which uses 10 kW. Maximum supply air flow 7.9 m3/s, maximum exhaust air flow is 8 m3/s. SFP = (10+10)/8 = 2.5

Day 2 Design - windows Passive House Seminar for Professionals from the Building Sector Placement of ventilation units  Need to be easy to access for maintenance  Try to avoid noise generated by the ventilation unit fans. For instance - place the unit in a closet (if using decentralised ventilation)  Placement close to an outer wall minimises the need for insulated ventilation ducts Picture: bsv arkitekter

Day 2 Design - windows Passive House Seminar for Professionals from the Building Sector Central – decentralised ventilation Central units One large unit needs less time for maintenance Easier to find adequate space needed for silencers Need careful planning with regard to fire-safety (if separate heating batteries are placed in each apartment) Decentralised ventilation units Each tenant can easier control their indoor climate Need careful planning regarding - placement to avoid insulation of pipes - find enough space for silencers - avoid short cut of air in inlet and outlet of air

Day 2 Design - windows Passive House Seminar for Professionals from the Building Sector Central or decentralised ventilation ?  Factors to take into consideration in the selection process: –Available space for Ducts and silencers; –is there a need for lowering the ceiling if using decentralized ventilation? -is there enough space in the attic to install ducts? -is it possible to place shafts in stairwells? Ventilation unit; –can it be placed in the attic or cellar? –is it possible to place in apartments regarding the need to obtain acoustic level requirements? –How will routines of maintenance be performed concerning... filter changes? adjustment of heating batteries?

Day 2 Design - windows Passive House Seminar for Professionals from the Building Sector Indoor comfort  The indoor climate is a combination of the four technical climates; –Air hygiene –Thermal climate –Acoustic climate –Visual climate Picture: Ulla Janson Supplied air - in rooms for daily get-together activities and in bedrooms (rooms with high air quality) Transferred air – from rooms with high air quality to rooms with lower air quality Exhausted air – from bathrooms and kitchens (rooms with low air quality)

Day 2 Design - windows Passive House Seminar for Professionals from the Building Sector Air distribution  The supplied air creates a comfortable indoor climate in the occupational zone  If the building is heated/cooled by air, the supply air devices must be customised for both warm and cold supply air temperatures Picture: Swegon