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GBE Equator v Northern Solutions (BrainDump) G#41897

By 2 June 2024July 1st, 2024Brain Dump, Code, Encyclopaedia

GBE Equator v Northern Solutions BrainDump

GBE > Encyclopaedia > Code > Brain Dump  G#41897

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GBE Equator v Northern Solutions BrainDump

University Education Environmental Module:

  • Whilst tutoring and lecturing Architectural Students in UK universities it dawned on me that a significant number of students were foreign students who may not be planning to work in UK or EU climates in their careers.
  • They may well return to their own countries with their own climates to practice as Architects.
  • I needed to clarify that much of what I was presenting related to northern hemisphere UK climate buffeted by 4 competing weather systems including being bathed in gulf stream warmth and humidity.
  • Every other climate will need different responses, some variations on northern solutions and but mostly radically different to northern solutions.

Climate specific solutions:

  • Many textbooks address northern hemisphere solutions, great care needs to be taken if copying or adopting these solutions in other climates.
  • I am not aware of publications addressing environmental issues related to hotter climates.
  • It is essential to apply joined up thinking with robust environmental know-how to adapt northern solutions or develop bespoke equatorial climate solutions.
  • It should be remembered that the UK will acquire Mediterranean weather conditions by 2050 whilst the sun paths will remain the same; some of what follows may well apply to the UK.
  • Mediterranean countries will have African possibly Sahara like weather conditions by 2050.
  • We have already seen short spells of these weather conditions across the Mediterranean and across Europe.
  • North-west Europe might even see the Gulf stream fail and radically colder conditions prevail.

Issues:

  • There are many issues to consider ranging from global through local to interior.
  • I will address some issues here, now and I will continue to add to them as they occur later.
  • Comments that follow address sites close to the north west African equator, close to its south facing coast, which is one of the hottest and driest parts of Africa, with some other UK or EU situations for comparison.

Energy and Carbon dioxide footprint:

  • There are two aspects to Energy and Carbon dioxide impacts: In use energy and carbon dioxide from heating or cooling and embodied energy and carbon in the materials used to construct the building, the second influences the first.
  • In extreme hot climates reliance upon air-conditioning will be tempting, but energy efficiency, carbon efficiency and cost efficiency need to be considered very robustly.
  • The ambition is to reduce reliance upon air conditioning by reducing the number of hours it is in use to say 20%.
  • If you deduct night-time hours 50%, when conditions can be cool, then we need to aim to reduce 30% aiming for say 5 hours maximum air conditioning use per 24-hour day.
  • There are lessons to be learned from termite mounds that have cool conditions in naturally ventilated earth-built structures that exploit summer heat to drive ventilation.
  • We cannot afford to be as sophisticated as termite mounds, but we can try.
  • Like termites we need to be aware of the position of the sun and direction of the wind and exploit them as much as possible to naturally exclude the sun and permit cooling wind.
  • Careful orientation of walls and windows can avoid solar heat gains and permit passive ventilation.
  • We can also choose materials to be low embodied energy and carbon: obvious examples include stone and sun backed earth.

Reduce Energy consumption:

  • Passive or active ventilation as much as possible by design.
  • Reduce need for mechanical ventilation or air conditioning by design.

Material choices to exploit their properties:

  • If heavy construction were the only way to keep buildings cool then embodied energy and carbon may well be high to meet site and building performances.
  • But thermal mass and decrement delay can be achieved with low mass and low carbon materials.
  • Decrement delay in a material helps to keep solar radiant heat out.
  • Low mass: medium and high-density insulation made of wood fibre, recycled newspaper, cork, cellular glass.
  • High mass: stone, rammed earth, cob, CobBauge, sun dried earth block.
  • Medium mass: Extruded cellular sun dried or fired clay, limecrete, hempcrete or concrete blocks.
  • But it is essential that we consider locally produced materials avoiding transport emissions.

Cavity external walls:

  • It has been promoted as a possible solution for equatorial construction, we can investigate its possibilities:
  • Invented to isolate wet outer leaf from dry inner leaf with a ventilated cavity in between in wet UK climate.
  • The outer leaf acts as rain-screen, any excess moisture can run down the inner face of the external leaf and drain outward.
  • Equator sites may be excessively dry and excessively hot, so this is not needed for moisture control.
  • 4” = 100 mm = 10 cm of fired clay or sun-dried earth brick can provide solar heat gain decrement delay, the ventilated cavity will cool the outer leaf and the inner leaf will protect from solar heat gains.
  • If a cavity wall is uninsulated, it will allow heat to egress through the inner leaf by conductivity and convection ventilation in the cavity.
  • The cavity must be ventilated at top and bottom to be effective, open perpends in masonry is enough in the UK.
  • If the cavity is insulated there is no convection ventilation cooling of the outer leaf subject to solar heat gains, there is also no convection ventilation cooling of the inner leaf subject to outwards heat conductivity.
  • I cannot see insulated cavity is a solution for a hot climate, but a ventilated cavity may work.
  • But with air conditioning anything could be made to work with a high energy, carbon and financial cost burden.

Albedo Effect and cooling of air:

  • The colour of the building and more importantly the roof and surrounding landscape affect the reflectivity of planet earth to solar radiation, albeit at microscopic level, but every little bit helps, and many bits add up.
  • One could argue that buildings at the north and south poles should be black to absorb any solar heat available and buildings at the equation should be white to reflect all solar heat.
  • Hard landscaping around buildings will potentially warm up the air reducing its potential to cool the building by cross ventilation.
  • Light coloured paving with low albedo will help paving to remain a little cooler avoiding warming any air currents being warmed before entering a building to potentially ventilate and cool the interior.
  • Black tarmac roads or car parking can add to outdoor air overheating feeding into cross ventilation and indoor air overheating.
  • Grass or ground cover planting can significantly cool the ground temperature to help cool the cross-ventilation air.
  • But grass and planting may require extensive irrigation to compensate for evaporative cooling and will add heavy water and energy demands.
  • Well-developed soft landscape with indigenous drought tolerant planting may well provide a cooling effect without the water burden.

GBE Equator v Northern Solutions BrainDump

Sites at the Equator:

  • 6 am sunrise, 12 hours daytime, 6 pm sunset, 12 hours night-time, all year round.
  • Seasonality is minimised but there may be other differences in weather patterns.
  • North point and latitude of the site is essential to know the orientation of the site, building, windows, rooms, roofs and Renewable Energy (RE) systems.
  • Positioning and orientation of rooms within a building and their windows is critical to keeping parts or functions of the building cool at the times they are used.
  • Examples:
    • Bedrooms do not want to be on the west side receiving evening sun, better on the east side receiving morning sunlight.
    • Utility, circulation and storage on the western hottest side
  • Equatorial African coast climate means evenings and night-time are very cold compared to daytime.
  • Europeans may find these temperatures agreeable, but they are cold for the indigenous population.

Sun paths and shading potential:

  • Mature indigenous palm trees, with very high small ‘canopies’ spaced well apart offer limited solar shading.
  • Palm trees will create a linear east-west shadow path on a site at the equator.

Solar shading:

  • Extensive solar shading of the whole site or the whole building footprint can be very beneficial to cool the whole space below a large canopy.
  • The space below such a canopy can be fully or partially occupied by building and separation from the canopy will reduce the temperature of the buildings below.
  • Extensive solar shading in the grounds may well provide some cooling effect upon the paved areas, where vehicles are parked and adjacent to cross-ventilation opening windows.
  • Indigenous palm trees, with very high small ‘canopy’ and spaced well apart offering limited solar shading.
  • Ideally closely spaced trees can offer a large volume canopy, effective as solar shading along the sun path.

Site investigation and land surveys:

  • Ariel or satellite photographs may be used to discover things not obvious at ground level:
  • Darker swirls across an area:
    • Could be underground watercourses with more ground cover, bushes, trees, palm trees?
    • Could be migratory routes?
    • Well-trodden by migratory animals, that urinate, defecate and break up the soil crust nourishing the land?
  • More investigation needed.

Desert environments:

  • Wind-blown sand can erode materials.
  • Wind-blown sand often accumulates around shrubs and creates sand dunes.
  • Wind-blown sand often accumulates around grounded rigid objects creating sand dunes that can bury objects.
  • Wind-blown sand creates sand dunes that will migrate as wind-blown sand progressively leap-frogs dunes.
  • Wind-blown sand may be too smooth which is why it may not be used successfully in concrete and sharp sand is known to be imported to make mortar and concrete.
  • Sand storms need to be anticipated since ventilation services can be overwhelmed and swimming pool filtration clogged.

Marine environments:

  • Marine sand is often smoothed by rubbing caused by constant ebb and flow of waves, currents and tides.
  • Coastal and tidal rivers exhibit moisture vapour and salty atmosphere that can reach sites up to 1 mile away in the UK;
  • In desert conditions their effect may be far more reaching, more investigation needed.
  • A salty crust may prevent rainwater from percolating into the subsoil, and run off during infrequent rainstorms.
  • Choose materials for corrosion resistance and durability in marine environments.

Desert and marine environment v planting:

  • Salt laden air limiting compatible planting species.
  • Ground water (if any) may be brackish (fresh infiltrated by salt) or all salt, limiting compatible planting species.
  • Low annual rainwater means planting needs to be drought tolerant.

GBE Equator v Northern Solutions BrainDump

Orientation of windows for sunlight:

  • At the equator, near vertical midday north and south sunlight are much the same and have very limited effect, unable to enter through windows and can almost be ignored.
  • At the equator, north and south daylight are much the same; can and should be exploited in place of artificial light.
  • At the equator, east and west sunlight are fundamentally important since they can lead to overheating in the morning and afternoon respectively.
  • West and east daylight are fundamentally important can offer passive lighting without overheating in the morning and afternoon respectively.
  • External walls could be aligned east-west so they do not get heated by overhead midday sunlight.
  • Opening windows could be positioned on the south and north elevations, for prevailing winds coming off the sea to the south or night-time winds from the desert to the north to cool the building by cross ventilation.

Orientation for natural light:

  • Windows letting in daylight or sunlight may also let in solar heat so take care with their design and shading.
  • Minimise eastern and western unshaded windows, maximise north and south unshaded windows at the equator.
  • Control morning east sunlight and afternoon west sunlight with bespoke solar shading.
  • Care with overheating by sunlight, make good use of morning west daylight and afternoon east daylight, southern light with high sun angles may also be cool.
  • There are many techniques to increase light penetration including:
  • Light shelves at windows 1/3 down from top of window bouncing light in through top glazing but very high sun angles may mean this is ineffective.
  • Light reflected from water outside of windows.
  • Light coloured walls and paving.
  • Roof lights (not facing upwards) letting light into upper levels to flood the interior with light from above.
  • Traditional mud huts make dark building interiors, new buildings need more daylight.
  • Many other issues come to mind, internal illumination by water filled bottle in roof, smoke from internal cooking.
  • Rammed earth construction is proving popular.
  • Cob and CobBauge (21st centrury earth and plant fibre version of earth building being studied at Plymouth University & EBUKI, Earth Building UK & Ireland, also in Australia and USA).
  • Earth building methods offer self-builders some non-skilled labour solutions that still need some expertise if building in Europe that may be easier to construct at the equator?
  • Earth building is mostly labour intensive which will be harder as equator weather conditions get hotter and dryer.
  • An alternative to consider is night-time working, but conditions may be too cold.
  • Prolonged night-time working at the equator is fundamentally bad for human health and wellbeing and should be limited or avoided.

Orientation for ventilation:

  • Determine prevailing wind direction.
  • But does that change diurnally (day to night) which often happens in desert zones.
  • Does morning ocean air bring cooling moisture laden air that can be exploited?
  • Make the building air permeable in the direction of prevailing wind flow?
  • Take care with solid site boundaries that blocks air flow.
  • Block heat from tarmac roads entering plots, gardens and houses.
  • Overnight cooling of thermally massive building internal surfaces can be achieved by purge ventilation.
  • Windows or vents that reach the soffit of the floor without the lintel depth below the floor soffit allow heat out of the space more readily, trapped heat at ceiling level will warm the soffit and keep it warm longer.
  • Sophisticated ironmongery may be essential?
  • Nigh-time purging of heat is reliant upon easy entry, easy air flows across hot surfaces and easy egress.

Solar Access:

  • Road and plot layouts could be prompted by an awareness of solar access, plot orientation and potential building and window orientation.
  • This may be advantageous in northern climates but may cause overheating if the designer is not considering window orientation close to the equator.
  • Buildings could overshadow its own site and gardens or adjacent sites but being close to equator means almost no shadow at midday but normal shadows morning and afternoon.
  • Awareness of surrounding sites and buildings and planting is important if planning to use renewable energy.

Shading devices:

  • Need to be designed for Equatorial sun angles: vertical midday sun, variable angles to east and west.
  • Consider limiting number and size of east and west windows and glass doors.
  • Solar shading is essential at south facing windows in northern hemisphere.
  • Large projecting solar shading is less critical at south facing windows at the Equator.
  • Short projections, roof overhangs or recessed walls should provide the shading that is needed.
  • Shading blades need to be spaced or angled to prevent sunlight passing through gaps between blades.
  • Windows to east and west need special care and attention to protect from morning and afternoon sunlight.
  • Blinkers adjacent to windows or screens in the landscape many be needed to control low level morning and afternoon sunlight.
  • Car parking could benefit from solar shading or cars will be impossible to enter until Air Conditioning (AC) has been running for a while.
  • Ideally cars are parked in basements or fully enclosed garages none of which should be air conditioned.

 Renewable Energy (RE):

  • Site and adjacent sites survey of buildings and landscape planting to determine shadow-free solar access.
  • Building design to be considered to avoid overshadowing by building walls, parapets, roofs, other RE installations, etc.
  • Photovoltaic (PV) panels for electrical power, artificial lighting, electric vehicle (EV) changing, can reduce in use carbon impacts.
  • PV can be 3D solar tracking (sunrise-sunset and summer-equinox-winter) but at the equator 2D (sunrise east, midday vertical and evening west) simplicity is possible.
  • Battery back-up can be considered to support uninterrupted power supply and EV charging.
  • PV orientation can be determined to match supply to demand, 16- to 24-hour demands can be provided for by single orientation PV for considerably less than 12 hours and big storage battery array; whilst multiple PV orientation and smaller storage battery array can work.
  • Photovoltaic Thermal (PVT) panels for electrical needs plus thermal panel to remove heat to maximise efficiency, heat can be used for domestic hot water and warming swimming pools, if desired.
  • Excess heat could be used in the extremely cold nights as domestic heating.
  • Excess heat can become a thermal pollution problem.
  • Excess heat can also be converted to coolth with additional technology.
  • Domestic Hot Water (DHW) by Solar Thermal (ST) panels are a very successful option, but visual impact may be an issue.
  • Domestic wind turbines have been ineffective, but new generations of Vertical Axis Wind Turbines (VAWT) have come of age and are very effective.
  • Survey needs to be carried out to determine ‘solar access’ and ‘wind access’ on site.
  • Marine environment corrosion potential needs to be considered in system choices and specification.
  • Sandstorm erosion or jamming or clogging up by sand may need to be considered.

Energy Efficiency Technology:

  • Once you have a plentiful supply of Renewable Energy this allows consideration of other heating and cooling technologies:
  • Coefficient or Performance (CoP): units of RE electricity in, 3-4 x units of heat energy out.
  • Consider conversion of excess heat to coolth.
  • For domestic hot water, swimming pool heating (if desirable), evening heating.
  • Ground Source Heat Pumps (GSHP): Vertical drilled or slinky below ground.
  • Water Source Heat Pump (WSHP): Vertical drilled like boreholes.
    • (sealed system no ground water pollution, only potential thermal pollution).
  • Air Source Heat Pump (ASHP): Above ground, located in hot-spot for optimised performance, can be located in overheating roofs.

GBE Equator v Northern Solutions BrainDump

Roof Geometry:

  • Flat, accessible, paved, and usable roofs are commonplace in hot climates but their construction method and materials choice needs care to avoid overheating.
  • Overhanging flat roofs can offer some solar shading to outdoor spaces below and some shading to windows.
  • Northern/European style pitched roof buildings may not be suitable for hot climate without great care in construction method and materials choices.
  • Room in pitched roof design will need special care to avoid overheating.
  • Pitched roofs work well for high rain fall areas, which may not be applicable at the equator.

Form factor:

  • In northern climate compact cubical or square plan buildings keep them low cost to heat.
  • At the equator compact cubical or square plan buildings keep them low cost to cool by air conditioning.
  • Less compact linear buildings may be easier to overheat due to having larger surface area to volume.
  • Less compact linear buildings may be easier to passively cool due to having larger surface area to volume.
  • More investigation needed.

Thermal mass:

  • Thermal mass can be used to absorb indoor air heat into dense materials leaving the air cooler but it needs to be designed well to succeed.
  • Some thermal mass can be exploited to keep occupants cool for longer into the day.
  • Some thermal mass can be exploited to keep occupants warmer for longer into the evening.
  • There are three ways to obtain or mimic thermal mass in building fabric:
  • Choose high thermal mass construction and materials to protect from solar heat gains.
    • Stone, brick, earth block, concrete block, concrete.
    • Consider which materials are readily available made locally without importing and long-distance transporting.
  • Choose high decrement delay thermal insulation materials in lightweight construction to protect from solar heat gains.
    • Decrement delay: The time it takes from external radiant heat to pass through external envelop materials and enter the building rooms or spaces.
    • Decrement delay: Needs to be 12 hours at the equator.
    • High specific heat capacity with density and low conductivity offers decrement delay.
    • Materials with decrement delay characteristics: Cellular glass, cellulose fibre, dense and medium density wood fibre, natural fibre insulations, cork.
    • But low conductivity may fight against controlling overheating.
    • More investigation needed.
  • Choose phase change materials that absorb heat when changing from liquid phase to solid phase and act like thermal mass.
    • But Phase Change Materials need to be able to cool down over night to be able to absorb more heat the next day.
    • Phase Change Materials: wax contained in sealed vessels or within multi-walled cardboard sells.
    • Phase Change Material Services: Can act as a heat-battery and used in domestic hot water or heating system.
    • Phase Change Material Systems: Sun Amp.

Surface thermal mass:

  • Solar heat gains through equatorial east and west windows can lead to hot interiors.
  • To try to control those heat gains, surface materials can be used to absorb the heat away from the room and the occupants.
  • High density high thermal mass materials can absorb this heat,
  • High density high thermal mass materials include: concrete, stone, brick or concrete block, ceramic tiles, stone tiles, cement-based boards, cement render, glass partitions, glass shower screens, etc. and China clay sanitaryware,
  • High density high thermal mass materials are often high embodied energy materials: Ceramic tiles, fired clay bricks, cement-based materials.
  • High density high thermal mass materials are sometimes high embodied carbon dioxide: anything cement-based, metals.
  • High density high thermal mass materials are sometimes low embodied carbon dioxide: stone, stone tiles
  • Heat absorbed can be exploited after the sun has set when temperatures fall, the heat can persist and be released keeping occupants warm for longer.
  • Too much heat absorbed into high thermal mass materials can reradiate heating the air, other objects and people and become a problem.

GBE Equator v Northern Solutions BrainDump

Site boundaries v Prevailing wind and cooling ventilation:

  • Well defined site boundaries with walls/fences may restrict ventilation across the site and interfere with any redirecting of air flow by bushes and trees.
  • Well defined site boundaries with walls/fences may keep tarmac road heat out of the site.

Stack ventilation:

  • Stack ventilation relies on warmed internal air to rise to high level vents and escape to outdoor open air.
  • The rising hot air draws air into building at low level, the ambition is that incoming air is cooler.
  • If outdoor air is already hot it will not be coming in cooler than indoor air and may fail to cool.
  • Outdoor air needs to be cooled by shading and/or evaporation.

Single sided room ventilation:

  • Is not as effective as cross ventilation (across the whole building).
  • A warm activity in a room or a room warmed by sunlight may act like stack effect in a single sided room ventilation.
  • Vents can come in many forms above and below or adjacent to windows and doors.
  • High level windows, clerestory windows, roof windows and rooflights.

Cross ventilation:

  • Is reliant upon a building being air permeable from any side to any other side, to correspond with prevailing or daily and nightly variable wind direction.
  • Consider security at the building perimeter and acoustic isolation/privacy/safety/security between rooms.
  • Simple or sophisticated ironmongery may be needed.
  • Balconies with glass balustrades will block air flow and reduce cross ventilation potential.

Windows and glazed doors:

  • Windows will need openings casements to permit passive ventilation, passive cooling and passive heat purging.
  • Windows without opening casements will come with reliance upon air conditioning and no passive ventilation purging overnight.
  • Easterly and westerly windows and glazed doors will need bespoke external solar shading to cope with solar gains from sunrise in the east and until sunset in the west.
  • Use of internal solar shading is less effective than external shading, it can be heated up and reradiate inwards.

Greenery and Landscape:

  • Trees and bushes:
    • European climate tall canopy tree and bush shapes can provide wind shelter and redirect air flows.
    • Tall palm trees or cacti cannot successfully participate in this activity.
    • Species of palm trees, cacti and bushes that are suitable for equator latitude, within marine atmosphere and potentially in marine or brackish ground water, that are leafed all year round need to be identified and specified.
    • Site boundary walls or fences may support or interfere with redirecting air flows using trees and bushes.
  • Grass:
    • Could have a significant cooling effect if it does not demand excess water and energy to maintain.
    • Artificial grass is not a solution.
  • Green Roofs:
    • Any concrete flat roof can provide solar heat gain protection to prevent overheating.
    • Solar protective measures (light-coloured solar reflective membranes, aggregates, paving or paints) will help to reduce solar heat gains.
    • Inhabited building usually needs to be thermally insulated against heat loss.
    • Adding the right thermal insulation material with decrement delay to a lightweight roof can provide protection against solar heat gains.
    • Adding a green, brown or blue roof will remove the benefit of a white roof; will add the bonus of added thermal mass in some cases and evaporative cooling in others, but other layers in the construction e.g. structure and ceilings will diminish their effects.

GBE Equator v Northern Solutions BrainDump

Palm tree and cacti species:

  • Trees need to be indigenous and compatible with desert climate and/or marine environment if within 1 mile of the coast and they may need special care and attention to survive.
  • If trees, bushes, ground cover, and other planting is introduced for solar shading, wind barriers, wind redirection, ground cooling, evaporative cooling are they competent species?
  • Example: Indigenous, Drought tolerant, Salt tolerant, Succulents, Deciduous/Evergreen?

 Evaporative cooling:

  • Night and morning ocean breezes can provide cooling to exposed thermal mass if the building is air permeable to allow purging of heat.
  • Cool waterbodies outside a building subjected to the sun can evaporate to cool any air passing over the waterbody and if that passes through an air permeable building this air can provide some cooling.
  • Cooled air passing around an airtight building will probably have little effect.
  • Take care with waterbodies becoming breeding grounds for insects.
  • Keeping water bodies clear of insects could be energy and chemistry intensive.

Passive Evaporative Cooling Wall (PECW):

  • Uses rainwater and sunlight to cool the building.
  • Sunlight, solar shading and shading of reflected solar radiation.
  • Water absorbed into porous clay tubes spaced apart to permit passage of ambient air flows the evaporating water will cool the air entering the building.
  • Equatorial sites may have no rainwater to exploit, coastal or tidal river sites salt, or brackish water may generate efflorescence and clog up the system.
  • The sun is too high in the sky at midday and the PECW may need to be solar tracking or numerous on east and west elevations or exploit winds off the sea or other waterbodies.

Swimming pools:

  • Pool water could offer evaporative cooling of cross ventilation air.
  • Strategic placement of the pool relative to opening windows and doors is critical to a cooling function.
  • Swimming pools offer recreation, health and wellbeing and cooling of people and air.
  • Excessive evaporation of pool water may become an issue and solar shading may help to reduce the burden.
  • Local well water near the coast may be brackish and require reverse osmosis desalination plant.
  • The chemistry and energy keeping the pool hygienic may be an additional burden.
  • Outdoor showers could be popular for cleaning off chemistry and cooling down without swimming.
  • There may be a need for privacy screening to the shower.
  • The impact of water systems can be reduced by use of PV photovoltaic renewable energy to all of them.

Outdoor recreation spaces:

  • Outdoor seating may well need some solar shading.
  • Outdoor seating space close to building may be surrounded by glass and masonry walls, with thermal mass that will make a ‘hot spot’ that may be too warm in the day but stay warm into the evening radiating heat to make the space comfortable for longer.
  • External paving will get hot and if adjacent to windows may re radiate heat inwards.
  • Hot paving may be challenging to walk on in bare feet?

Roman Courtyard House:

  • It has been suggested that this format may be applicable in an equatorial setting, we can investigate its potential:
  • Invented for the mediterranean climate and used across the roman empire but not equatorial application.
  • A solid wall is built at the site perimeter, raised to a ridge line of a mono-pitched inverted truncated pyramidal roof.
  • The eaves at the low edge of the roof will form a rectangular opening to the sky and be supported on beams and columns.
  • The accommodation is located between the permitter wall and stops short of the eaves at the opening leaving a courtyard opening with a covered walkway around its perimeter.
  • All rooms face the courtyard so privacy needs to be considered especially to bedrooms and bathrooms,
    • 4 or 5 layers of glass can provide that privacy, so can net curtain, blinds, etc.
  • Internal corners of the perimeter accommodation will have little or no windows or daylight so locate storage and utility rooms there.
  • The perimeter wall excludes wind-blown sand but also prevents any cross wind cooling the accommodation and courtyard.
  • Since midday sunlight is vertical then the light falling directly into the courtyard will heat any paving.
    • Replacing some or all of the paving with a pool for evaporative cooling could be advantageous.
  • Morning and evening sunlight will fall at angles and may benefit from well considered solar shading.
  • The courtyard could become very hot warming the surrounding rooms.
  • Cross ventilation is impractical so active ventilation may be worth considering.
  • Active ventilation can come in the form of scoops that capture any breeze above the building, driving the air down into the accommodation and or courtyard.
    • If two scoops are used they may need to be different profiles so that there is a difference in the aerodynamics and a flow occurs between them inside the accommodation.
    • A variation on the scoops is to have concentric pipes one for inwards air flow and the other for outward air flow, the inward air pushes the outward air flow.
    • Ventilation within the accommodation will need to be considered carefully to be effective, removing VOCs CO2, heat, steam, smells, without compromising acoustic privacy.
  • The pitched roof needs to protect the occupants from solar radiation so needs thermal mass and/or decrement delay.
  • The pitched roof offers opportunities for services penetrations, vents, but take care that the services are sleeved to prevent heat entry.
  • The pitched roof offers opportunities for rooflights for sunlight, daylight, views of the sky or palm trees, ventilation but take care with overheating.

GBE Equator v Northern Solutions BrainDump

Modern Methods of Construction (MMC):

  • Numerous manufacturers are promoting MMC as solutions for equatorial sites, we can investigate its potential:
  • Advantages:
    • Pre-assembly in a factory and simpler faster installation assembly on site will limit the hours of labouring on site in hostile weather conditions.
    • Potential to control quality, minimise site generated waste.
    • Precast concrete options can provide thermal mass and decrement delay.
    • Lightweight options can be insulated with the right materials to provide thermal mass and decrement delay.
    • Foundations might be simplified to steel piles, but flat roofed buildings will need to be anchored down.
  • Disadvantages:
    • Logistics of delivery over potentially challenging roadways.
    • Crane Handling of Modules, Pods or Panels on a sandy site (road sub bases may solve that).
    • Lightweight options are likely to suffer from overheating.
    • Thin construction using high performance conductivity thermal insulation will overheat.
    • Wind-blown sand will find any weaknesses in airtightness and jam up joints.
  • Conclusions:
    • None until each proposed system is considered in detail.
    • Set a thorough robust brief, employer’s requirements or specification and check all criteria are met by proposals.

Autonomous services:

  • There is no municipal infrastructure, Africans leap-frogged infrastructure and readily adopted autonomy:
  • Solar thermal (ST) for domestic hot water, PV power, PVT power and thermal, PV power for communications, mobile phone (still needs masts), Satellite TV, Satellite Communications, e.g. Skylink, Satellite Phones, etc.
  • Autonomy at this scale needs:
  • Accessible plant room(s) of a suitable size to accommodate numerous systems and enable maintenance of them.
  • Plant rooms can be at basement, ground, upper or roof levels; basements are potentially cooler, roofs are potentially hotter.
  • Site or basements to accommodate underground vessels to store ‘autonomous sewerage’ to keep them cooler, with vents and outfall drains.
    • Composting toilets: if there is a beneficial use for the compost.
    • Settlement tanks: smaller to collect solids, allow liquids to pass and emptied more frequently.
      • Liquids need to be treated to a suitable level.
    • Septic tanks: larger to collect all liquids and solids emptied less frequently.
    • There needs to be a municipal sewerage plant to dispose to, or these are not viable.
      • We do not need raw sewerage being dumped on open land.
      • Unless it can be beneficially composted to rejuvenate soil.
    • Biomass: sewerage extraction of methane or ethane gas for burning.
    • Biomass: but human sewerage has low calorific value if burned directly.
  • Rainwater harvesting should be considered essential in a hot dry climate to capture any rainwater no matter how small or infrequent, climate change may change this frequency, applications include:
    • WC flushing in place of potable drinking water.
    • Landscape irrigation could also be a priority.
    • Vehicle or EV cleaning.
  • Grey water recycling: sink, basin, shower and bathwater collection, storage with some treatment and reuse
    • WC flushing in place of potable drinking water.
    • Landscape irrigation could also be a priority.
  • Land is expensive so building a desalination plant to provide drinking water may not be high priority.
  • Piped drinking water supply may be considered later at whole development level.

Materials sourcing:

  • Everything you want is already available in the market.
  • Building materials are made locally or imported.
  • Imported from: Spain, UK, India, China, etc.

Supply chains:

  • If building specific systems are absent in the market, it may be worth investigating other sources.
  • There are many manufacturers making for live-aboard camper van and nautical adventurers needing compact economic all year round services autonomy.

Recycling economy is robust and diverse:

  • Whenever there are enough people to serve, others with a cart, trailer or truck will set up enterprises serving them.
  • Piggybacking off any development will be possible.
  • Food waste to composting or anaerobic digestion at individual or community level are possible.
  • Composting of food waste to replenish soil nutrients and provide water retention can transform landscapes in a less-intensive way.
  • Plastic materials recycled into locally made wheelie bins, etc.

GBE Equator v Northern Solutions BrainDump

© GBE GBC GRC GIC GGC GBL NGS ASWS Brian Murphy aka BrianSpecMan ******
2nd June 2024 – 1st July 2024

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GBE Equator v Northern Solutions BrainDump

© GBE GBC GRC GIC GGC GBL NGS ASWS Brian Murphy aka BrianSpecMan ******
2nd June 2024 – 3rd June 2024

See Also:

GBE Equator v Northern Solutions BrainDump

GBE Templates

GBE Brain Dump

Template

  • GBE Brain Dump (Template) G#20308 (this page)

GBE Brainstorm

GBE Books

GBE CPD

GBE Issues

GBE Issue papers

GBE Projects

GBE Equator v Northern Solutions BrainDump

© GBE GBC GRC GIC GGC GBL NGS ASWS Brian Murphy aka BrianSpecMan ******
2nd June 2024 – 3rd June 2024

GBE Equator v Northern Solutions (BrainDump) G#41897 End.

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