GBE Overheating CPD

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GBE Overheating CPD
About:

Number of Slides:
- 2019: 73 of __
- 2017: 27 of 54
FileSize:
- 2019
  - PDF Handout: 5mb
  - PDF Show: 15mb
  - PPTX: 15mb
- 2017
  - 12.4 Mb (PPTX)
  - 13.3 Mb (PDF Show)
  - 3.2 MB (PDF Handout)
File Name:
- GBE CPD Overheating A01BRM230917 PPTX Show
- GBE CPD Overheating S27.pdf PDF Show
- GBE CPD Overheating 9H3.pdf PDF Handout
- GBE CPD Overheating CIOB 111119 PPTX show
- GBE CPD Overheating CIOB 111119 S73 B+W PDF Show
- GBE CPD Overheating CIOB 111119 9H9 B+W PDF Handout
File Format:
- PPTX
- PDF of PPTX
Scope: Overheating Issue paper CPD
Extract: none
Content: Overheating images and explanation
Created for: Construction Industry
Presented to: NET_Learning Erasmus+ Project 2017; CIOB Herts 2019
Author: BrianSpecMan aka Brian Murphy BSc Dip Arch (Hons+Dist)
© GBE NGS ASWS 2015 – 2019
Created: 12/09/2017
Revision: A01 & A02 & A03
Updated: 13/11/2019
Previously published on Scribd: N/A
Scribd reads: N/A
CI/SfB: (NN)
CAWS: LNN
Uniclass: LNNNN
CAWS 2012: NN:NN:NN
Tags: GBE, Issue paper, Overheating, Problems Solutions, Images,
ProductSets: Methods of Construction, Materials, Properties, Building Elements, Building Performance,
UserGroups: Students, Architects, Assistants, Technicians, Structural Engineers, Constructors, Housing Providers

GBE Seminar Text

Build Light, Insulate Right, Solar Tight

Or why buildings overheat
© 2015-2019

If you are an educator or a student

If you want Architectural Education to embrace Climate Emergency
Call for Curriculum Change
Sign up now: Full name, School, Email
Join 2090 signatures 09/11/19
https://www.architectureeducationdelares.com
Use your mobile and join

This Presentation on GBE:

Find this file on GBE website at:
https://GreenBuildingEncyclopaedia.uk/?P=15750
This file has been updated
Website will be updated after this event
- –Handout/print/read PDF file
- –Show PDF file
- –Show PPTX file

Scope

The Climate Emergency
Building Regulations
- –SAP Standard Assessment Procedures
The Performance Gap,
- –Airtightness, Thermal bridges and Psi values
Books to circulate.
- –Passivhaus
- –The Zero Carbon Hub
- –The Buildings Hub
- –Tom Dollard’s book Design to Perform
GBE Overheating
- –Materials samples
- –The right and wrong materials for overheating.
- –Case studies
GBE Whole building calculators

Global awareness has risen

1, 2, 3 or 4 decades late (never too late)
Trashed Film (to invited professionals and MPs 2013)
- –If you have an audience get the CD to show
David Attenborough Blue Planet
- –Ocean Plastics, straws in particular 2019
Greta Thunberg
- –Started school strike for Climate 2018
- –Behaviour Change campaign
  - Government, Business & Individuals
  - Unite behind the Science
- –Embraced Globally 2019
- –SchoolStrike4Climate
  - Asked the Adults to join them 20/10/2019
  - And we did in large numbers 4 million globally

Change is coming?

Architects Declare
- –Starchitects signed (700+Practices signed)
  - But look at their portfolios
    - –Greenwash?
    - –Still accept holiday resort airport commissions
- –Rejected me as a solution provider (not RIBA)
Construction Declare
Architecture Education Declare
- –Accepted me (2090 signed by 09/11/19)
Architects CAN Carbon Action Network
- –Architects Can’t, don’t have the know-how
- –Education failed them

We do have the know-how

TGR The Green Register
- –Membership and training group since 2000
- –facilitating CPD by many specialists to many generalists
- –PHT, TRA, BBA, AECB: CL CLR, ASBP, etc.
- –To fill the knowledge gap

We told you so

11,000 scientists
153 countries
Declare
- ‘we’re facing untold climate suffering’
Urgent action required
- –Nov 2019
- –40 years of disclosure ignored
- –debate and inadequate Governance
- –Problems
- –Solutions

RIBA Plan of Work

Circular diagram
- –Circular information-only flow
0-7 = — Linear Building
8 = Repurposing and Reuse of existing
9 = Deconstruct, reclaim, reuse, reassembly
0-9 = Circular Building

RIBA Education Committee

Out of touch with Climate Emergency
- –Universities not leading the way
- –Few unite behind the science
- –Very few being taught science of building
- –Considering dropping Part 3 Professional Practice
University Aspiration: Architectural Association
- –Philosophical BS
- –Fantasy Graphics
Never engage with reality
- –let alone solve the problems
RIBA Sustainable Futures
–Campaign coming to challenge
–ARB & RIBA Education Committee
-On Health and Safety Grounds
-Not environmental Grounds

The Climate Emergency

Carbon Dioxide CO2 (since industrial revolution)
- –Man-made
- –Large scale, difficult, tinkered with, mostly Ignored
- –Gov. Money invested in RE E&H (2015 withdrawn)
Ozone (1980s)
- –Man-made
- –Easy and 1st phase Semi-sorted
- –2nd Phase still to follow
Methane CH4 (growing and became big problem 2019)
- –21 x the global warming potential of CO2
- –Decomposing Nature
  - Thawing of permafrost land, ice and ocean floor sediment
  - Ignite bubbling oceans, ponds, ice, tap water
- –Unstoppable if global warming continues

Design & Detail Guidance

Building Regulations (legal minimum)
- –SAP Standard Assessment Procedure
Principles of Element Design
- –Performance (ignore thicknesses in diagrams)
Construction Guidance
- –IBO Passivhaus/Eco
- –NewBuild and Refurb books
Zero Carbon Hub/The Buildings Hub
- –Briefing Design & Detailing Failures/Guidance
Tom Dollard Book: Design to Perform an illustrated guide to delivering Energy Efficient homes
Retrofit Guidance
- –PAS 2030 Installation PAS 2035 Design
Energy Standards
- –GBE Whole Building Calculators

Standard Assessment Procedures (SAP)

Building Regulations never set good targets
- –Hopeless for meeting Carbon targets
- –Focus on U values, not overheating and weak on airtightness
- –Spec Housing Developers: Working to older versions
- –Performance Gap falling way behind
SAP Never was good enough
- –Just Building Regulations Compliance assessment
- –AECB carried out a line by line comparison with PHPP
  - UKGBC published it on PinPoint
- –Never understood low energy buildings well enough
- –Retrofit for the Future: showed it was bad at Refurb too
Not a modeling tool
- –Easy to assume your way into believing your building will be okay
Thermal bridging: easy to fudge your way through with false details and psi values, BCO unable to check
Overheating assessment: Easy to fudge

Passivhaus & PHPP

Based on Indoor comfort conditions
Correct U values to reduce heat loss
Glazing U values to feel no coolth
Eliminate thermal bridges, reduce risk of interstitial condensation, mould, structural failure
Mechanical Ventilation with heat recovery to not kill anybody by chemical off-gassing or carbon dioxide
Passivhaus PHPP software does a better job of overheating analysis
But:
MVHR installed in overheating attic will overheat house
MVHR with blocked filters will run inefficient and noisily and get turned off

Zero Carbon Hub ZCH

Funded by Government for 10 years
Find out how well we are doing
Set Targets
Discovered buildings do not perform to Building Regulations standards

The major weaknesses are:

Airtightness
- –Designers do not design and specify it
- –Red line it and and make it a site issue
- –Builders can’t make building airtight
- –Without spending money and time on materials they do not understand
- –Won’t employ specialists
- –Brown envelopes were known to be dished out
Thermal bridges & Psi values
- –Complicated and time consuming process to work out accurate Psi values
- –SAP calculations accept wildly inaccurate Psi values
- –BCO do not understand them well enough to check them
- –BCO need to have a specific education to do their job now
Overheating
- –Found 20% of homes overheat,
- –New homes worse %

The Performance Gap

ZCH coined ‘Performance Gap’ between designed and actual performance
Challenged Spec Housing to up its game
Developed many report and guides: ignored by designers
Developed Builders publications on good and bad details
- –Finally something that designers could learn from
- –Like hot cakes at EcoBuild exchanged for business cards

Zero Carbon Hub Publications

–Free to download PDFs
- ZCH Builders’ Book
- ZCH Thermal Bridge Guide
- ZCH Services Guide
- ZCH SAP untangled
- ZCH Ventilation Guide
–www.zerocarbonhub.org

Zero Carbon Hub Success

They did understand overheating:
- –Summer
  - Happens in top floors
  - On south-west elevations solar gain through glazing
  - Inadequate ventilation
  - Glazed stairs feeding solar heat into corridors to flats
- –Winter:
  - Due to district heating pipe in corridors and insulation issues
  - Code of Practice conflicting flow and return temperatures
  - Domestic interface plumbing valves uninsulated
  - Inadequate consumer controls

Zero Carbon Hub failing

Despite everything they never got the bottom of one major issue:
- –Solar radiation enters through opaque building fabric
- –Not just glazing
- –Lightweight roofs let in solar radiant heat through the tiles and slates and plasterboard
- –Conventional insulation does not stop it
- –Conventional included glass wool, stone wool, polystyrene
- –Lightweight walls suffer as well

The Buildings Hub TBH

Government dropped Zero carbon target
ZCH was now redundant
The Building Hub set up to follow on
Free to download PDFs
TBH Designer’s Handbook
www.thebuildingshub.org

Tom Dollard Book:

Design to Perform an illustrated guide to delivering Energy Efficient Homes
- –RIBA Publishing
- –ISBN 978-1-8946-996-5
Brian Murphy proof read early draft
Builds on the work of ZCH
The Performance Gap: how to reduce it
How to Detail thermally efficient envelopes
Addresses services failures too

GBE Whole Building Calculators

GBE Green Building Encyclopaedia
GBE Calculator
Building Size: Lengths Areas Volumes
Regulations/Design standards:
- –U value Set Selection
Winter Thermal Insulation Material Choices
- –K values v U values = Thicknesses
But don’t forget Decrement Delay
- –to avoid summer overheating
And acoustics, fire, moisture management, etc.

Many Energy Regulations and Design Standards compared

None address Overheating calculations

Decrement Delay

GBE Calculator

Energy and related design standards

Building Regulations Approved Document L
- –Will eventually aim to meet carbon targets but not now
- –Most new buildings will need to be retrofit by 2030-2050
Energy (exceeding Building Regulations)
- –AECB Bronze, Silver, Gold and Platinum Standard
- –Super E (Canadian; means to sell their softwood)
- –Passivhaus (German) PHPP Software
  - Indoor Air Quality and Thermal Comfort conditions driven
  - Mimimise air leakage, minimise thermal bridges
  - EnerPHit (Passivhaus Retrofit)
- –Minergie (Swiss)
- –Carbon Lite (UK AECB)
  - Passivhaus interpretation for UK climate and energy mix
  - Carbon Lite Retrofit (CLR)

Materials > k values > U values > Thicknesses

GBE Issue Paper: Overheating

2015 lots of internet chatter about overheating
Not understanding the whole truth
GBE joined in, it became clear a lot of misunderstanding exists
Started writing a GBE Issue Paper
“Build Light > Insulate Right > Solar Tight”
124 pages later revision 14
Emptied my head of know-how
111 pages and revision 11 published on GBE
https://greenbuildingencyclopaedia.uk/?p=145

GBE CPD: Overheating

GBE Issue Paper CPD
© 2015-2017
124 pages reduced to 34 slides that follow

Battle Of Weather Fronts

Ever changing competing weather fronts keep UK average mild, wet and windy
Not normally the same weather for prolonged periods
But high level jet stream having greater variation and influence

House + Loft Envelope

House+Attic
20th century construction
Has its fair share of problems: inadequate insulation, airtightness, acoustics, etc.

Overheating Of Buildings

Top floors and south facing rooms get sunny and overheat
Not just through the glass, but through the opaque fabric too
Roofs and walls
Air Conditioning is not the answer

General Approach

Winter: Small windows to the north, big windows to the south
Summer: Small windows to the south or solar shading needed

Back To Back Housing

Back to back
19th Century design relic
What is it still doing here in the 21st C?
Fiduciary Rules?
Cheap and profitable
Very common in multi-storey flats

Passive Hub Norwich

South facing for winter solar gains
And summer overheating?
Needs summer solar shading and winter solar penetration

Learning from termite mounds

Building termite mounds above ground subjects the colony to summer sun
Facing N-S means the mound avoids midday sun but also exploits cooling
Offices can do that too

Internal Heat Transfer

Keep heat in its place of arrival
Maintain safe refuge on the cooler side
Insulate internal floors and partitions
Close doors
Promoted by BedZED

Roof Top Extensions

Planners insist on top floor additions set-back
Structure needs lightweight construction
Comes with with wrong insulation
Will overheat
Needs air-con

New Penthouses

Roof Top extensions
Usually overheat
Try as hard as you like with bits and pieces
‘Comfort Cooling’ sounds cool but its still air-conditioning bad for the planet

Radient v Conductive

Radiant verses Conductive heat flows
Insulation needs to resist both or overheating occurs

Radiant v Conductive

Thermal Insulation:
Once radiant heat gets in it warms the space and the warmth cannot get out through conductivity insulation

Radiant v Conductive

UK Government funded insulation programmes
Refurbishment and retrofit
Cavity insulation
Attic insulation
Cheap materials: glass and stone wool or polystyrene: all conductive insulation
Will overheat top floors

Roof Insulation

Wrong, right and no insulation
Some work some do not
Choose carefully
Roof Insulation

Building Integrated Renewables

Is it really a good idea?
I don’t think so
Non-BIR ventilate below and perform better
BIR radiate below into a hot attic

Solar Panel Layouts

Solar panel layout to avoid overshadowing by one panel on another
Winter is worse
Get your angles right
Solar Panel Layouts

Solar tracking: 1

Universal joint on pedestal supporting frame and panels
Motors and levers adjusts the frame angle
Allows panning to track the sun during day
Allows adjustment to keep panel orthogonal to the suns rays through the seasons of the year
PVs pick up sunlight and daylight
Solar Tracking Panels

Solar tracking: 2

Hinge on pedestal supporting frame and panels
Panel tilted to be orthogonal towards sun at mid-day summer facing south
Motors and levers adjusts the panel angle
Allows swivelling on hinge to face sun facing east in morning, south mid day and west in evening

Corrugated Fibre Cement or Metal Roof

Thin lightweight coverings offer no protection from solar radiation heat gains
And rainstorm water noise

Profiled Metal Roofing

Profiled Metal roof cladding
No insulation or plastic sandwich panel
Both ineffective against solar gains

Concrete Flat Roof

Concrete and Asphalt Flat Roof
No Insulation
High Decrement Delay concrete
No overheating
Well eventually

Timber Flat Asphalt Roof

Old timber and asphalt roofs keep you roasting in summer well into the evening as they cool down

Victorians knew a thing or two: water is good solar protection

Strengthen your roof to carry the load
Raise upstands to hold the water and have enough height for an overflow
Flood your roof with water
Keep it topped up on evapourative sunny windy days
Solar protection
Resists uplift
Finds leaks if there any

An Assortment Of Cavity Walls

Cavity masonry walls
20th century construction
Its on its last legs or is it?
1919-2019?

An Assortment Of Cavity Walls

Since its forced introduction and demise of the solid brick wall in 1919 the cavity wall has served a purpose.
It kept the weather out
I stopped the suns radiant heat
As regulations started to stop us wasting heat, insulation was introduced into the cavity with varying levels of success
But for the 21st century its on its last legs
300 mm of full fill cavity wall insulation is at the upper limit
Lintels, Cavity tray DPCs, cavity closers and wall ties are struggling to keep up
That won’t stop us using it though

An Assortment Of Cavity Walls

Cavity masonry walls
20th century construction
Its on its last legs
1919-20??

An Assortment Of Cavity Walls

Cavity masonry walls
20th century construction
Its on its last legs
1919-20??

Flexible Living Space

The sun moves around the building
In big buildings you can move away from the heat to cooler parts on extreme days

Overheating Of Glazed Offices

100% Glass facades
20th century construction
Fuel poverty (cooling) or Wellbeing might stop it
We need 100% solar shading or 100% air conditioning
Agile working might help share the burden

Consider the external landscape around a building

Hard landscape can be light in colour reflect some heat or dark and absorb it
It will then reheat the air in the vicinity and may pre-warm air entering via windows
Soft landscape can cool the air with shade and moisture
Wet landscape can cool the air by moisture evapouration
Reflections off water will be dappled

Trees can cool air passing by and shade buildings directly

Trees are an essential part of cooling urban areas
The stop sun from reaching hard paving preventing it being heated and pre-heating air
Trees also shade windows and roofs to prevent direct overheating
Deciduous trees drop their leaves and permit winter sun to reach the building

Moving Solar Gain Heat to Cold Areas

Hot floor slabs fitted with under floor heating pipes can move heat to the colder parts and visa versa
Suffolk CC in Ipswich

Moving Solar Gain Heat to Cold Areas

Heat Transfer from Glazed Entrance stairs, to corridors, to flats
Glazed communal stairs and corridors serving apartments student accommodation
Everything overheats

Badly insulated buildings squander heat

Hospitals require 24 hour heating
Windows need to be triple glazed for thermal comfort of patients in jimjams
Building should be so well insulated that they do not need heating
Radiators on external wall below windows squanders heat 24 hours of day/night

Stair wells and rooflights can provide passive cooling using stack effect

With fresh air inlets at ground floor and vents at roof level, stair wells can permit heat build ups to dissipate upwards
But in winter they cool the building

Passive ventilation via atrium is obvious with easily overcome problems

Opening at floor perimeters and rooflights over atrium is easy enough
But some floors will overheat for no apparent reasons
Lower floor hot air buoyancy may create a barrier to upper floor air entering atrium
Controlled perimeter vents will balance the floors to ensure equal access to atrium

Winter sun traps need to be well ventilated in summer

Sun spaces at BedZED are on the south side to get maximum exposure in winter
Internal glazing is shut to keep heat in sunspace
When there is enough heat then open doors to let heat in to warm the rooms
Top floor does not have enough shading and can overheat

Exposed Thermal Mass in floors and roof

When the doors are opened between dwelling and sun space the heat is permitted to enter the rooms
Any excess heat will be absorbed by the exposed thermal mass floors, walls and roof

Office Buildings need thermal mass to absorb excess heat

But the thermal mass must be on show and exploitable
Raised Access floors and ceilings prevent its use
Metal trough deck floors exclude use of thermal mass

Lightweight building ‘fabric’ cannot stop solar gains

It will be unbearably hot on sunny days
But as soon as the sun sets they will rapidly cool down and be suitable for the evening ‘Show’

Light weight cladding may not be enough thermal mass to stop solar radiant heat

Stone fibre, glass fibre, plastic thermal insulation will not stop solar radiation heat gains
So the interior could overheat
However the blockwork wall behind will stop the heat getting in

Thermal bridges will ruin any choice of insulation material performance

Thermal bridges will let conducted heat out, conducted coolth in and solar radiant heat in
Eaves details are most vulnerable
300 mm of insulation reduced to 50 mm is asking for trouble
Risking interstitial condensation, surface condensation, mould, structural failure, asthma, toxic mould and death

Materials samples

The right and wrong materials for overheating:
Use of high decrement delay thermal insulation materials at:
- –rafter level will delay radiant solar heat gain from entering the attic.
- –ceiling level will delay radiant solar heat gain from the entering the rooms below.
Using low conductivity insulation at:
- –ceiling level will stop heat in attic air from conducting down to the rooms below.
- ceiling level will stop heat getting out via the attic.
Very hot attics in summer will provide sufficient heat to overcome the resistance of thermal conductivity insulation and heat the rooms below.
Solar heat gains via windows will heat the upper floor rooms
Use of only:
- –low conductivity thermal insulation in attics will help upper floor overheating in summer.
- –high decrement delay thermal insulation in attics can prevent upper floor overheating in summer.
The thickness of the high decrement delay thermal insulation will determine the period of delay, 10-12 hours is sufficient to avoid all overheating.
The same issues can affect lightweight construction walls if not protected by masonry outer leaf or some form of solar protective rain-screen cladding, which does not reradiate inwards.

Case studies

GBE CPD SunSpace WinterGarden Conservatory png
https://greenbuildingencyclopaedia.uk/?p =294

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Feedback

These files are created by generalists with a big dollop of green flavour
These files are updated from time to time
We are not experts so from time to time these file may get out of date or may be wrong.
If you feel that we have got it wrong please let us know so we can put it right

Brian Murphy ONC HNC Construction BSc Dip Architecture (Hons+Dist)
- –Technician & Architect by Training
- –Specification Writer by Choice
- –Environmentalist by Actions
Greening up my act since 1999
Founded National Green Specification 2001
Launched www.greenspec.co.uk 2003
Created: GBE at https://greenbuildingencyclopaedia.uk 2015
E BrianSpecMan@aol.com
Twitter: http://twitter.com/brianspecman
LinkedIn: BrianSpecMan
Facebook: BrianSpecMan Facebook: http://www.facebook.com/brianspecman
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