ICA Role. Is this a Duplication of Resources?

Independent Commissioning Agent (ICA)

Green Star, among other ratings schemes offers points for the employ of an ICA. (Refer to Green Star documentation for details).

Here we go again, another ‘get out jail’ for the designer. Don’t get me wrong any commissioning and building tuning is greatly supported, by me.

Where did commissioning in design go? When did it go? Why did it go?

Multiple reasons I’m sure including:

  • Low Fees (must do a wordage search on how many times I see those words)
  • Buildings Built for Sale and not long term operation and ownership
  • Construction management style of building delivery
  • Loss of skills base (good engineers leaving the industry).

Note: Commissioning is not just commissioning the systems to work. It also should include building tuning. This will require the commissioning period to be extended into the defects liability or warranty period, and beyond, if required. The warranty period should become a period of tuning and checking to ensure that the systems are performing at their optimum efficiency during all climatic variations for the occupied building.

Designers Role

It’s absolutely the design engineers role to detail how the commissioning is to be undertaken, what and how it’s to be commissioned and incorporate in their designs  the; valves; dampers; straight lengths of ducts, meters, indication lights and everything else needed.

The designer documents should detail who can commission the systems, the qualifications and necessary experience required. This is, in many ways, a self-preservation act i.e. you need a good commissioning contractor to make your life easy.

It is not the designer’s role to actually commission any systems or set up a commissioning program and the like. However the consultant is responsible for reviewing said documents and final witnessing approval.

Client Role or Clients Representative Role

Clear instruction should be provided when seeking consultant fees. Note: Commissioning should be done regardless of Green Star points and sufficient time to commission should be allowed for in the building program.

Example Scope:

Provide integrated design and commissioning documents to enable the works to be tendered for complete installation and commissioning and building tuning.

Commissioning Works to include:

  • Description of each system to be commissioned
  • Detailed functional description, including full load, low load and partial load operational requirements.
  • BMS points list
  • For each system provide pre commissioning tests and commissioning tests required.
  • For each system detail the commissioning results to be achieved.
  • Include in the design all items required to be able to commissioning the system including:
    • Pitot traverse points
    • Valves
    • Dampers
    • Sensors
    • Gauges, Immersion Sensors, Test Points, Dosing pots etc.
  • Specify the requirements of the commissioning contractor including:
    • NEBB qualifications
    • Previous successfully commissioned similar buildings
    • Staff and staff experience
    • Commissioning program
    • Commissioning test reports

 Summary

Commissioning and Building Tuning is always required and should be allowed for, regardless of Green Star points.

The designer and in particular the mechanical designer should document the commissioning requirements for the project.

An interesting overlap occurs between the designer and the ICA, if appointed for Green star points.

Author: Jorgen Knox

Date: 12/08/2014

Contact: e: jorgenk@knoxadv.com.au, t: 02 800 33 100, w: KAE, LI

Not ESD Savvy – 5 Stars is still within reach

Simple Ways to Save Energy

This post discusses simple ways to save energy. It is expected this post will be updated regularly.

Also see ‘Natural AHU’ Post

You don’t need to be ESD Savvy

So how do we consume energy?

  • Lighting to see
  • Electrons for power
  • Cooling and Heating to feel comfortable and air to breath
  • Hot Water
  • Etc

 

 Commercial Sector Buildings Energy End Use (2006)
Commercial Sector Buildings Energy End Use (2006)

Source: DOE, 2008 Buildings Energy Data Book, Section 3.1.4, 2008.
Note: This pie chart uses an adjustment factor (*) used by the EIA to reconcile two datasets.

STEP 1: Stop Energy Loads, At Source, including:

  • Lighting
  • Cooling
  • Heating
  • Hot Water

STEP 2: Make Systems as Efficient As Possible:

  • Lighting
  • Cooling
  • Heating
  • Hot Water

STEP 1: Stop Energy At Source

Lighting to See

  • Use Natural Light
  • Get rid of the concept of providing high levels of lighting everywhere. Provide desk lighting with individual user on/off control (with LED bulbs).
  • Use LED Lights (no excuses, technology and pricing is here)
  • Turn those lights off. LED lighting can come with individual sensors. If a room is unoccupied, the lights go off.
  • Zone your lighting to take account of natural day light
  • Use light colours

Cooling

Step 1: Stop the heat coming in. As a minimum comply with the BCA.

  • Think about operable blinds
  • Use great glazing
  • Insulation
  • And Insulation. Get real and check the Actual U values (Thermal Bridging).
  • Seal the Building. And get it checked…air pressure test.

Infiltration especially in older building is a big issue.

LOAD EXAMPLE:

An office of say 1500 m2 and 2.8 m high

Poor façade: infiltration at 0.5 ac/hour: Cooling load: 8 kW each hour (of additional cooling).

Better façade: infiltration at 0.2 ac/hour: 3.4 kW each hour (of additional cooling).

  • Use low energy consuming equipment

Step 2: reduce your outside air supply  & temperature.

  • Monitor the air quality and reduce outside air (CO2 monitoring).

I’m modern offices, home working and hot desking is the norm. Thus on any given day the number of occupants (driving outside air requirements) is less than design (typically 1 person per 10 square meters). BUT the plant continues to deliver design outside air.

At certain times of the year the office occupancy is down to a skeleton crew…BUT the plant continues to deliver design outside air.

  • Have smaller zones. If no occupants turn off the outside air
  • Pre cool the outside air with:
    •               Room air, already cooled
    •               Thermal labyrinths
    •               A water feature
    •               Air intake from shaded location

Step 3: Increase the room air temperature. What’s wrong with 27 oC instead of 24 oC?

Step 4: Just like lighting, who says a whole floor needs to be at a constant uniform temperature.

Also, using those LED occupancy sensors that come with those LED lights, turn off AC to areas that are not occupied.

  • Consider communal open plan areas at 27o
  • Consider a small fan for each user on their desk.
  • Consider a high velocity VAV cold air duct system to provide localised spot cooling.

Heating   

Step 1: Stop the heat getting out. As a minimum comply with the BCA.

  • Think about operable blinds (let sunlight (heat in)
  • Consider the glazing type
  • Insulation
  • And Insulation. Get real and check the Actual U values (Thermal Bridging).
  • Seal the Building. And get it checked…air pressure test.
  • Pre heat hot water from waste or solar sources.

Step 2: reduce your outside air supply temperature.

  • Monitor the air quality and reduce outside air.
  • Have smaller zones. If no occupants turn off the outside air
  • Pre heat the outside air with:

Room air already heated

Thermal labyrinths (SOL Air)

Air intake from a sunny location

Step 3: Decrease the room air temperature. What’s wrong with 19 oC instead of 24 oC?

Step 4: Just like lighting, who says a whole floor needs to be at a constant uniform temperature.

  • Consider communal open plan areas at 19o
  • Consider a high velocity VAV warm air duct system to provide localised spot cooling.

Step 5: Temperature Drift (End of Day)

At the end of the day, let the room temperature drift upwards, allowing a larger buffer, so in the morning the space needs less energy input to get back up to temperature.

Hot Water (Not Drinking Hot Water)

  • Limit the amount of hot water you need
  • Lower water temperatures (avoid heating up to only blend down)
  • Pre heat mains cold water with the sun
  • Heat hot water with the sun
  • Limit pipe lengths to avoid long warm up delays
  • Turn off those zip heaters

 

All the above are simple ideas and any engineer can incorporate into a design. Get these right and you’re on the way to a 5 star building.

STEP 2: Efficiency Improvers

Add some more of the following efficiency measures, and things only get better:

  • Don’t use electricity for chillers.

Got roof space? If yes consider evacuated solar tubes (Other collectors available). These systems will heat water to the required temperature (c. 95 oC) to use in absorption chillers.

Thermax Hot Water Absorption Chillers

hot-water-driven-chillers-img[1]

Solar Cooling (Simplified Schematic)

solar-based-cooling[1]

  • Efficient  Chillers  (HIGH COP’s)

If you have to use electric chillers then use the best available (Highest COP). Don’t forget this is where you should spend your money…this is the biggest energy consumer in your building…the backbone of your HVAC system.

Chiller Efficency

Consider chillers that use:

  • Permanent magnet motor
  • Active magnetic bearings
  • Oil free system

 

  • Efficient Chiller System Design (Pipework)

Consider non traditional pipework system to increase chiller efficiency, such as Series Counter-flow.

Series Counter Flow Chillers

Series Counter Flow ChillersTraditionally large central plant chillers have been connected in a ‘parallel’ pipework system. Each chiller receives the same condenser water temperature &chilled water return water temperature and cools and delivers chilled water at the desired temperature. Each chiller does the same ‘work’.

the two chillers in the diagram above, are acting as a two-stage chiller, sharing the waterside lift and resulting in lower lift for each chiller compared to parallel piping and is thus more efficient. Thus overall the system efficiency is increased.

Note: Series counter flow adoption is not always the best option. Factors such  as climatic conditions, building cooling load
profile, the use of economy cycles, airside system design and utilisation schedule all play a part in determining the viability of this pipework arrangement.

  • Adiabatic cooling. This is using wet bulb free cooling (water sprays)
  • Economy cycles. Using cooler air than inside air t do the cooling for you.
  • Night Purge/Building Flushing
  •  Smaller Thermal Zones

The smaller the thermal zone the less over supply of air will occur to a floor. PCA Premium grade buildings typically use 80m2 zone sizes for perimeter areas and 120 m2 for interior zones, with each zone having 1 VAV box controlling air to that zone.

Imagine each diffuser sensing the temperature of the air local to itself and modulating the air supplied. Air flow to the floor will be reduced (less fan power) and better thermal comfort will be achieved.

Rickard diffusers, by Fantech, are a provider of such motorised VAV diffusers (youtube link).

 

  • Use on floor plant (reduces fan power, responds to floor temperatures, not common or averaged temperatures)
  • Slower heat up/cool down times (so what if you’re not at exactly the right temperature for an extra half hour a day.
  • High Efficiency Chillers, pumps, fans and the like
  • Turning of your chillers at peak electrical demand and let your pipework provide free cooling (big heat sink)
  • Using tight shut off dampers on plant not in use
  • Low resistance ductwork and pipework (fan and pump power)
  • Right Sizing of plant so it runs at peak efficiency for most of a year
  • Variable speed everything
  • Simple and Robust controls with reporting. Provide an energy dashboard for all tenants to view
  • COMMISSIONING AND PROVING

Most high star rated buildings achieve their stars from the simple initiatives above. For me star ratings don’t mean much (all sorts of bizarre points available)…your aiming for low utility bills and low CO2 …..NABERS Star Rating.

Looking at it the other way…WHY don’t all commercial buildings achieve 5 stars?

  • Poor façade
  • Inefficient Lights
  • Low COP plant used including step control of compressors (now NCC requirement for plant exceeding min cooling load)
  • Poor thermal zoning of air handling plant including combining zones
  • In ability to turn down systems on reduced load
  • Poor controls and control sensors out of calibration
  • Stuck dampers allowing in too much outside air
  • High supply air temperatures used (increasing fan power)
  • Humidity control systems causing over cooling and re heating
  • No economy cycle provided (now NCC requirement for plant exceeding min cooling load)
  • Plant and systems oversizing

Author: Jorgen Knox

Last Up-dated: 4/03/2016

Contact: e: jorgenk@knoxadv.com.au, t: 02 800 33 100, w: KAE, LI

D & C versus Full Design

Full Design or D&C?

This post discusses D&C vs Full documentation.

Should I fully document a project or go D&C?  

This question is normally answered by the Architect or the Project Manager at the very outset of a project. This is a fundamental decision point. The rest of the team have no input, indeed the project, or potential project is very often still under wraps.

If you’re going D&C, then the team should be involving D&C (design and construct) contractors (Builder, HVAC, Elec, Hydraulic and so on contractors) from the start.

If this is too hard (D&C contractors involved early), then your heading for the Full Design approach with usual consultant input or the half-way house, where the team (including Architect and Consultants), get the project to say 30% and then start the D&C process (The hope is that the 30% work is not abortive).

Basically it comes down to hard dollars (again) and trust. The hard dollars (will I get a cheaper price if I fully document and go to competitive tender) and the trust (can I trust a D&C contractor not to rip me off).

My Views

I’ve been asked this question so many times over the years (D&C vs Full documentation).

There is no clear best way to document a project. It always comes down to the individuals, either on the consulting team or the D&C team. See also my post on competitions.

I have seen a trend towards the D&C approach.

The typical pros are:

  • It’s cheaper (cuts out the consultant)
  • Full responsibility lies with the contractor and it was always going to.

The typical conns are:

  • A perception you will be ripped off
  • D&C design isn’t as good.
  • Full documentation means there are ‘no variations’.
  • The building may be too far down the track when the D&C contractor is appointed.

Are Consultants Creating the D&C approach?

My call is yes. There is a definite move to providing less in consultant documentation. Two classic examples are shown below.

E.g. 1: Its easier (Time wise, PI insurance etc) to not show balancing dampers on a drawing or commissioning valves and so on. Just put a note on the drawing or in the specification and let the contractor work it out.

Eg. 2: Co-ordination, will it fit? Let the contractor work it out attitude often pervades.

So, if the consultant is providing a concept design and in reality a schematic layout, you can see why industry groups think “I might as well just use the contractor”.

In the consultants defence a client fees may be so low, that all you can do is dust off the last similar project and regurgitate it.

If you’re a services contractor

If you’re a contractor with the willingness to employ great staff and undertake projects in a fair and reasonable manner, then absolutely the opportunity to excel and win work without consultant input is there.

Main D&C Contractors

The large and good D&C contractors are generally forgotten in the process. They are often frustrated having to tender on documentation, which is consultant derived and can be considered useless. Wrong Concept employed, not representing best value to the client, un coordinated drawings (that just can’t work) etc are the comments you hear on that side of the fence.

What Should Consultants Be Doing

I’ve been a consultant for most of my career, so forgive me for my slight bias.

A consultant should be offering more than great drawings.  And clients should be using consultants to do more than just ‘great drawings’.

What a consultant should be doing:

  • Ascertaining what the client wants
  • Ascertain what the Architect wants
  • Ascertain what the site will allow
  • Review the world wide market and report to the team the options available, with life expectancy, power and water consumption etc. (LCC). So the client can make the best and most informed decision.
  • Concept design, spatial planning
  • Setting minimum standards.

Summary: Providing the smarts

At this point the consultant can be moved to a watching brief role or if they have the skill set move to a ‘documentation consulting’ role. For the Architects reading, this is all similar to the ‘Concept Architect’ and ‘Documenting Architect’ roles.

If a consultant provides all the services above in a watered-down fashion (due to low fees shall we say), they will not be thanked and push more work the D&C route.

Summary

I’ve sat on the fence a bit on this one, but hopefully covered off the main topic items. I have not covered PI insurance on purpose. Your feedback and experiences would be appreciated…write a comment.

Author: Jorgen Knox

Date: 12/08/2014

Contact: e: jorgenk@knoxadv.com.au, t: 02 800 33 100, w: KAE, LI

Residential Corridors and Gas Meter Cupboards

Gas Meter Ventilation – Residential Buildings

This post discusses the need to provide ventilation to meter cupboards, in residential, non fire escape corridors.

Gas meters are, of late, finding themselves in corridor cupboards.

The Gas Code (now AS 5601) requires these enclosures to be ventilated. The Gas code provides guidance on this.

There is some apparent confusion as to whether the corridor needs to provide sufficient ventilation, to in turn ventilate the gas meter cupboard.

My reading of the code is that the corridor must also be ventilated in accordance with the gas code. This can be by permanent natural openings to outside (see adjoining room requirements in the Gas Code) or the meter cupboard can be ventilated via mechanical means….duct and fan.

Note: it is my understanding the air pressure in the gas cupboard should be neutral or negative. This is to prevent gas being ‘pushed’ into any adjoining spaces.

Not providing ventilation may allow gas to build up in a corridor with a ‘poor outcome’ and obviously contravene the Gas Safety Act.

What to Do?

Speak with your projects Hydraulic Consultant. If they are proposing no ventilation, or ventilation to another space, which in turn is not ventilated, get this in writing and also get this backed up, again in writing, by the gas supplier/authority (Jemena).

A cupboard on an outside wall can be ventilated direct to outside…look to get this on your project.

Qualification

The above is my personal opinion and must not be used on any project. Seek your project consultants’ expert advice.

Author: Jorgen Knox

Date: 11/08/2014

Contact: e: jorgenk@knoxadv.com.au, t: 02 800 33 100, w: KAE, LI

Competitions and More Competitions

Competitions and More Competitions?

This post promotes the use of engineering competitions for buildings. Given the total cost of ownership of a building, the services solution(s), is nearly as important as the Architectural solution.

Many clients hold competitions to get the best Architectural design. They recognise there are many brilliant Architects out there and a competition allows for the idea and not the company to shine.

Why doesn’t this occur for the engineering services for a building?

It’s a given the Architectural solution has the biggest impact on all of us, in a community and place of work or home sense.

Once the Architect is on board the rest of the design team seems to be selected on the usual grounds…fees and the usual due diligence and sometimes just the usual ‘friendlies’.

Each building has its uniqueness and opportunities and at any given time there are individuals and companies who will have the right and best solution.

Benefits and Losses

Bare with me if you’re a visual only person…. from a buildings operational point of view, occupant comfort and cost of building ownership, the services engineer has a massive impact. The right engineer with the right system will bring untold benefits to the project.

Usual Benefits include:

  • Services design works
  • Life expectancy of services in line with building type
  • Running costs of building
  • Health and well-being of occupants
  • Thermal comfort
  • Visual comfort
  • And so on

Not so usual benefits include:

  • Winning edge to a team’s bid
  • Ability to enter and win awards
  • Low energy consuming building (happy everyone)
  • Reduced spatial needs
  • Adaptability
  • Free energy systems
  • Adoption of cutting edge technology and remaining ahead of the curve

Summary

Going to competition on services will ensure the best solution is put to the client, for that building.

A competition will in effect act as design development by the market place and removes design development by an engineering company, with fee constraints leading to a formulaic solution.

Author: Jorgen Knox

Date: 11/08/2014

Contact: e: jorgenk@knoxadv.com.au, t: 02 800 33 100, w: KAE, LI

Natural AHU

Can we ventilate, heat and cool a building without a traditional air conditioning unit?

In short, yes you can.

Heating and cooling a building has been done for a long time, without a chiller and air handling unit.

As a concept, ignore for now the detail, comfort criteria and the like and concentrate on what an air handling unit does in a building. This is summarised below:

  • Delivers outside air for occupants to breath and removes or dilutes odours and the like – FAN
  • Provides cooling, due to internal and external heat gains – COOLING
  • Provides heating – HEATING

Fan, Cooling and Heating – Passively

Fan: Moving air through a building can be achieved by many methods including:

  • Cross ventilation
  • Thermal chimney
  • Room Stratification

Cooling: Cooling can be done, examples include:

  • Pre Cooling via thermal labyrinth
  • Wet bulb cooling via water features
  • Thermal mass in contact with ground

Heating: Heating can be done, examples include:

  • Suns energy direct to a space, often combined with thermal mass
  • Pre warming air using the concept of SOL air temperature

If we can design our buildings to capture, release and utilise the above then we have created a ‘natural AHU’.

So why don’t we do this more?

Simple, as society develops, we expect perfect internal conditions and for these conditions to be maintained within close tolerances. We expect to be able to wear summer clothing all year round. If this pre meditation is removed the ‘Natural AHU’ would be able to provide ‘acceptable’ conditions for a large number of buildings.

Design Process

As a starting point for each building the design team should start with trying to get the ‘natural AHU’ to work. Then in a step fashion tweak the design to the final solution keeping the concept of the ‘Natural AHU’ as intact as possible.

Examples

Free CO reduction/control

Many, many carparks, can be naturally ventilated.  However there is no BCA requirements to force or encourage a design to be made naturally ventilated.  So, the majority of car parks end up with fully fanned power consuming car parks. Going the hard yards to allow for extra excavation or perimeter openings is often ‘too difficult’. From an energy prospective, Im always frustrated. But in reality we are all working for a client and its simply hard dollars.

Free Cooling

Many small to medium offices are provided with hybrid systems (both natural and mechanical means to control the internal environment). The term office natzi is often used here. This is a person who’s role it is to managed the opening and closing of windows and switching off the air conditioning button, if someone turns it on. Its quite funny that most of us in our home lives wouldn’t dream of using the air conditioning (due to cost), but at the office, no problem. So in this type of office acceptable conditions can be achieved.

Nursing homes, offer a great opportunity to provide ‘natural AHU’s’. These developments now often include internal garden areas opening onto large internal circulation spaces. Provide operable roof to these external gardens, add plants (free oxygen) and a water feature (free cooling) and you’ve just created a ‘natural AHU’. Air can be drawn into the courtyard, directed over the water feature (free cooling) and into the space. Further work within the space will allow for this air to be directed through the corridors and into each room (before being removed naturally or by the toilet exhaust system).

For the neigh Sayers

I’m often on the side of the neigh Sayers, as an Engineer, and can come up with a significant list of issues that seem to prevent the ‘natural AHU’. A hospital I hear you say, can’t be naturally conditioned, a laboratory and so on.

Well even these specialist buildings can have significant parts of the floor plate conditioned with a ‘natural AHU’.

For a city office block, with high CO levels surrounding the site, buildings on 3 sides and high ambient noise levels, then the challenges to the natural AHU start mounting up. At this point we do what we can (refer to Design Process paragraph above). ‘Do what we can’ isn’t a cop out…with some out of the box thinking we can significantly reduce the reliance on the ‘mechanical AHU’.

What Next

To get the ‘Natural AHU’ concept working needs an alternative thought process.

  • An aspirational client
  • An Architect willing to invest time in passive control and able to Architecturally make the passive control part of the Architectural solution.
  • An Engineer, who wants to challenge the norm and not just knock out a chilled water VAV system.

Author: Jorgen Knox

Date: 11/08/2014

Contact: e: jorgenk@knoxadv.com.au, t: 02 800 33 100, w: KAE, LI