Introduction - Regensw
Introduction What is a low energy home? Total energy including unregulated (cooking and appliances)
18000
kWh total energy use
16000 14000 12000 10000 8000 6000 4000 2000 0
2002 Part L house
2006 Part L house
Code level 6 house
A Typical New Build (2006 Part L) DER as %
Roof 2.0%
0 . 4
Ventilation losses 18.5%
Thermal bridging 10%
Space heating 51.5% (made up of heat losses shown)
Walls 8.0%
Windows 8.5% Door 1.9%
DHW use 20%
DHW losses 10.5%
Lighting 15% G floor 2.5%
Pumps and fans 3%
Hanham Hall Carbon Challenge Site A specification for achieving Code level 6 •True zero carbon •Heat Loss Parameter (HLP) of 0.8 W/m2K •A* rated material required for credits
Orientation Benefits of correct orientation: •Winter solar gains •Glazed area also gives good day-lighting Space heat (kWh)
-12%
Solar gain (W)
7000
700
6000
600
5000
500
4000
400
3000
300
2000
200
1000
100
0
0 80% North
80% East
80% South
80% West
Managing Summer Solar Gains Overheating managed by: •Over-shading •balconies, roof overhangs & porticos •Minimise internal gains from appliances and lighting •Placing of thermal mass •dense internal lining boards with SIPs •Occupant controlled measures •Passive night purge •Reduce surrounding hard standing
Modelling and Managing Over Heating SAPs ability to model overheating is limited Homes modelled in IES v5.6 APACHE Includes: insulation, internal heat gains, thermal mass, sun path modelling, occupant control, solar gains
IES model
CIBSE design summer year used
Model results
Suncast model
Modelling and Managing Over Heating Results of overheating calculations Impact of removing balcony and portico on summer overheating. The result is significant overheating of the living room. Model results
Building Fabric In order to reduce heat loss, (U valuesW/m2k) •Walls = 0.12 •Ground Floor = 0.12 •Roof = 0.1 •Doors = 1.4 •Window = 0.7
Building Fabric Wall thickness 300mm – KINGSPAN TEK 125mm WALL PANEL KOOLTHERM K18 - 70mm
Roof thickness 350mm – KINGSPAN TEK 142 ROOF PANEL KOOLTHERM K18 - 80mm
Windows triple glazed Triple glazed No trickle vents Low e, argon fill (also lower transmittance)
G Floor thickness 450mm – 300mm deep Celcon Floor Elements 120mm of Kingspan K3
Construction Detailing Good construction detailing gives: •Low thermal bridging •Part L accredited details halve thermal bridging against backstop •With off-site SIP panel possible to halve again
•Low air permeability •Hanham designed to 1 m3/hm2 (@50pa) 3 m3/hm2 (@50pa) used in model to be conservative
•Achieved by: SIP panel jointing system •Achieved by: Offsite preparation
Services and ventilation Mechanical ventilation 0.5 air changes/ hour required 3 m3/hm2 (@50pa) gives only 0.15 changes/ hour
90% heat recovery from extract air (compared to 66% in SAP)
Low specific fan power (1.2W/l/s compared to 2W/l/s in SAP)
Lighting Skylight roof lantern maximises lighting to the stair
Day-lighting calculation proves Code compliance: •Kitchens must achieve Daylight Factor 2%+ •Living rooms, dining rooms, studies DF of 1.5%+ •80 % of working planes in kitchen, living rooms, studies must receive direct light from sky
100% low energy fixed internal lighting All external lighting energy efficient, with daylight detection •Max 150W, daylight and movement controls
Review of Oak Meadow Case Study 35 Ecohomes for Devon & Cornwall Hosing Associating
2007 Chosen by the Housing Corporation as an example of how social housing “could and should look” 2005 Sustainable development of the year 2005 Best social housing development 2004 Devon Environmental Business Initiative, 2003 Green Apple Award - National Champion
Review of Oak Meadow Case Study •Terraced to minimise heat loss •Double skin timber frames- 300mm cellulose insulation •Wall, floor and roof prefab offsite panels •Sustainable timber cladding •Triple glazed •Thermal mass in the internal walls & solid ground floors •The buildings should not require space heating •‘Cool Larder’, a highly insulated space which is kept very cool by air drawn in through clay pipes, laid deep underground
Review of Oak Meadow Case Study
IES Apache suite used Numerous construction types tested •
Test temperature stability
Extra thermal mass required to stabilise temperature
Bedroom temperature stability Tem p era tu re va ria tion (K)
Thermal modelling for heat loads and to prevent overheating
8.0 7.0 6.0 5.0
Summer
4.0
Autumn
3.0
Winter
2.0 1.0 0.0 0
50000
100000
150000
200000
250000
Thermal mass (J/m2K)
300000
350000
Review of Oak Meadow Case Study Occupant feedback extremely positive: “During our first winter (Dec 04-Spring 05) we used the central heating for a total of 4 hours (total - not per day!) “ “The floor downstairs is terra-cotta tiled throughout - it stays wonderfully cool in summer and retains heat in winter thanks to the underground insulation layer”
18000
kWh total energy use
16000 14000 12000 10000 8000 6000 4000 2000 0
2002 Part L house
2006 Part L house
Code level 6 house
A Typical New Build (2006 Part L) DER as %
Roof 2.0%
0 . 4
Ventilation losses 18.5%
Thermal bridging 10%
Space heating 51.5% (made up of heat losses shown)
Walls 8.0%
Windows 8.5% Door 1.9%
DHW use 20%
DHW losses 10.5%
Lighting 15% G floor 2.5%
Pumps and fans 3%
Hanham Hall Carbon Challenge Site A specification for achieving Code level 6 •True zero carbon •Heat Loss Parameter (HLP) of 0.8 W/m2K •A* rated material required for credits
Orientation Benefits of correct orientation: •Winter solar gains •Glazed area also gives good day-lighting Space heat (kWh)
-12%
Solar gain (W)
7000
700
6000
600
5000
500
4000
400
3000
300
2000
200
1000
100
0
0 80% North
80% East
80% South
80% West
Managing Summer Solar Gains Overheating managed by: •Over-shading •balconies, roof overhangs & porticos •Minimise internal gains from appliances and lighting •Placing of thermal mass •dense internal lining boards with SIPs •Occupant controlled measures •Passive night purge •Reduce surrounding hard standing
Modelling and Managing Over Heating SAPs ability to model overheating is limited Homes modelled in IES v5.6 APACHE Includes: insulation, internal heat gains, thermal mass, sun path modelling, occupant control, solar gains
IES model
CIBSE design summer year used
Model results
Suncast model
Modelling and Managing Over Heating Results of overheating calculations Impact of removing balcony and portico on summer overheating. The result is significant overheating of the living room. Model results
Building Fabric In order to reduce heat loss, (U valuesW/m2k) •Walls = 0.12 •Ground Floor = 0.12 •Roof = 0.1 •Doors = 1.4 •Window = 0.7
Building Fabric Wall thickness 300mm – KINGSPAN TEK 125mm WALL PANEL KOOLTHERM K18 - 70mm
Roof thickness 350mm – KINGSPAN TEK 142 ROOF PANEL KOOLTHERM K18 - 80mm
Windows triple glazed Triple glazed No trickle vents Low e, argon fill (also lower transmittance)
G Floor thickness 450mm – 300mm deep Celcon Floor Elements 120mm of Kingspan K3
Construction Detailing Good construction detailing gives: •Low thermal bridging •Part L accredited details halve thermal bridging against backstop •With off-site SIP panel possible to halve again
•Low air permeability •Hanham designed to 1 m3/hm2 (@50pa) 3 m3/hm2 (@50pa) used in model to be conservative
•Achieved by: SIP panel jointing system •Achieved by: Offsite preparation
Services and ventilation Mechanical ventilation 0.5 air changes/ hour required 3 m3/hm2 (@50pa) gives only 0.15 changes/ hour
90% heat recovery from extract air (compared to 66% in SAP)
Low specific fan power (1.2W/l/s compared to 2W/l/s in SAP)
Lighting Skylight roof lantern maximises lighting to the stair
Day-lighting calculation proves Code compliance: •Kitchens must achieve Daylight Factor 2%+ •Living rooms, dining rooms, studies DF of 1.5%+ •80 % of working planes in kitchen, living rooms, studies must receive direct light from sky
100% low energy fixed internal lighting All external lighting energy efficient, with daylight detection •Max 150W, daylight and movement controls
Review of Oak Meadow Case Study 35 Ecohomes for Devon & Cornwall Hosing Associating
2007 Chosen by the Housing Corporation as an example of how social housing “could and should look” 2005 Sustainable development of the year 2005 Best social housing development 2004 Devon Environmental Business Initiative, 2003 Green Apple Award - National Champion
Review of Oak Meadow Case Study •Terraced to minimise heat loss •Double skin timber frames- 300mm cellulose insulation •Wall, floor and roof prefab offsite panels •Sustainable timber cladding •Triple glazed •Thermal mass in the internal walls & solid ground floors •The buildings should not require space heating •‘Cool Larder’, a highly insulated space which is kept very cool by air drawn in through clay pipes, laid deep underground
Review of Oak Meadow Case Study
IES Apache suite used Numerous construction types tested •
Test temperature stability
Extra thermal mass required to stabilise temperature
Bedroom temperature stability Tem p era tu re va ria tion (K)
Thermal modelling for heat loads and to prevent overheating
8.0 7.0 6.0 5.0
Summer
4.0
Autumn
3.0
Winter
2.0 1.0 0.0 0
50000
100000
150000
200000
250000
Thermal mass (J/m2K)
300000
350000
Review of Oak Meadow Case Study Occupant feedback extremely positive: “During our first winter (Dec 04-Spring 05) we used the central heating for a total of 4 hours (total - not per day!) “ “The floor downstairs is terra-cotta tiled throughout - it stays wonderfully cool in summer and retains heat in winter thanks to the underground insulation layer”
