Mid-tier buildings make up 80% of Australia’s commercial building sector and present easy opportunities to improve energy efficiency for the built environment. While these non-premium buildings have often been neglected, addressing the energy efficiency not only reduces costs, but translates into vast benefits such as increased occupancy comfort and attracting/retaining both key tenants and employee talent. Read through to see the challenges, initiatives, options, and rewards by addressing energy efficiency in this sector.
Updated Design, Attention to Detail, & Problem Solving
While bittersweet about coming to an end of my time volunteering with Project Mexico and saying goodbye to new friends, it’s great looking back on all the fun times alongside what I’ve had the pleasure of learning. The greatest points of interest to me related to the updated design, attention to detail, and problem solving required throughout the building process.
In an effort to provide our families with greater opportunities, many different approaches were reviewed to update the established house design from previous years. Options such as a finished interior, plumbing, electricity, furniture, and a larger size were reviewed. In the end, a larger footprint for the house was chosen as it would provide the family with more potential. While a finished interior is nice at a certain level, leaving it unfinished creates a partnership with the families to take ownership and transform the resulting shell into their home.
One of the most obvious changes was in the size of the house, with almost twice the floor area. While leveling a larger area was a minor effort adjustment, challenges arose in tighter working areas for small parcels of land and greater tenacity to hand mix all the required batches of concrete.
Walls & Roof
With the increase in floor area came an A-frame roof to support the larger design, contrasting with the previously single-sided roof. While the wooden wall and roof panels had previously been constructed from 2x4s, and were famously fun to build, the new panels are now templated with metal framing for a lightweight, yet strong structure. This approach speeds up framing day as the smaller templated panels are prefabbed ahead of time. Additional benefits include fireproofing, increased lifespan, and fun with power tools while joining panels together.
Stuccoing is an age-old technique of sealing buildings and adding structural strength from ceiling to floor. The chicken wire and underlying paper provide a surface for the stucco to stick to during application. With a looser to mix recipe than concrete, it is mixed to a slightly different consistency for easier application.
With the second layer of stucco finished and briefly allowed to dry, a few coats of natural limewash paint is then applied atop the stucco. Although white has been used primarily, different colour pigment options allow for a bit of customisation here. While it dries over a few days, it improves the aesthetics at a surface level while reinforcing the structure as it seeps in and also adds antibacterial properties to the external layer. This methodology developed with the practice of spring cleaning wherein a home’s contents would be emptied out and fresh layers of limewash applied to the internal walls to freshen and clean the home.
Along with updating the individual home design, sights have also been set on improving the surrounding community. A simple way of doing this is by offering fresh coats of limewash to neighbours during the normal build week. This is easily done in parallel with little additional effort and helps to build community support and sentiment.
Attention to Detail
In order to build a water-tight, secure, and safe home to live in, thoughtfulness at each step is required whether leveling the ground, mixing concrete, attaching chicken wire, installing windows and doors, or assembling the roof.
This importance starts at the beginning with the foundation of the house held down by a combination of anchor bolts and concrete nails; the anchor bolts embedded in the concrete pad pull down on the house frame from below while concrete nail bolts push the frame down from above. The anchor bolts have to be placed precisely at the right depth while accounting for any bowing of the concrete pad, or else it won’t be properly secured and the house frame can easily be out of square.
When hanging the chicken wire, it’s important that it be installed as tight as possible and all the way down to the bottom of the concrete pad. When the chicken wire is held tightly against the house frame, this ensures that the wall will be more uniform and strong, avoiding stucco from falling behind the chicken wire where the paper is slack. The proper strength prevents the stucco wall from cracking down the track if the wall experiences trauma such as a kid bouncing a ball off of it. With the chicken wire held to the bottom of the concrete pad, the wall is more secure and water-tight, preventing water from seeping in during heavy rain where the wall and pad meet beneath.
Another aspect of water-proofing is in the installation of the doors and windows. Installing these before the first coat of stucco ensures a good seal between the two stucco coats while giving a nicer finish, especially when painting. On the inside, applying a foam spray in the gaps provides support for the stucco as well as good insulation.
When it comes to applying stucco, the application is important for enabling a good seal. The right consistency helps with smooth application, while scoring the wall after the first coat, wetting the wall before the 2nd coat, and including adhesive in the 2nd coat recipe ensures that the layers stick together properly for longevity. The stucco also needs to be applied all the way to the top where the wall meets the plywood on the underside of the roof to avoid any gaps where air, moisture, or bugs and critters can sneak into the house.
Regardless of the site, issues related to safety, foundation support and longevity, tight working areas, water supply, or material inconsistencies would arise and require methodical problem solving from the site team.
Occasionally, I’d find my rusty Spanish to be the best on site, with the challenge of speaking to the family about important decisions such as the home’s location and orientation, placement of doors and windows, safety, and foundation support.
With the small parcels of land, there were often tight working spaces around the building site, either juxtaposed with neighbouring properties or cliff edges. Often, these parcels of land were built up with dirt for the foundation of the house, but with the intense rainy seasons the dirt could easily give way without retaining walls. Families were advised to finish building the anticipated retaining walls around the house as soon as possible for good longevity. In the meantime we built working platforms into the slopes where required for the safety of our volunteers.
With limited running water service in TJ, an additional cultural challenge was consistently having enough water to mix concrete, stucco, lime paint, and wash tools. The standard approach is to wave down “Pipa” trucks to fill open-top “Tambos”, or drums, from the large tank reservoir that they cart around. While usually seen driving around neighborhoods, at the times we needed them most is when they seemed to be avoiding us or we’d encounter “Poopa” trucks which empty septic tanks. We’d often employ lookouts at neighbouring work sites and send out scouts in cars to track down a water source. When in a real jam, sometimes we found neighbours kind enough to let us siphon buckets of water or gravel for a few bucks to finish off our concrete pads. At my most desperate time, we stopped by a road construction project and settled for the crude, muddy, irrigation water that they were kind enough to share with us!
The loose measurement tolerances of our suppliers constantly kept us on our toes, whether it was an undersized delivery of gravel and sand, different length wall or roof panels, oversized window/door frames, or missing/incorrectly-sized plywood pieces. A bit of customisation, use of scraps, creative team brainstorming, and divine intervention always brought us through in the end to finish our builds confidently each week.
This Summer has been an amazing experience, not only working alongside an inspiring group of Project Mexico workers, the orphanage staff, the weekly volunteers, and those throughout the general community, but also being a part of the updated house design and build process. I have been continually impressed by the attention to detail and problem solving that happens at every site by the blending of the teamwork, cooperation, and expertise of all the members involved to build a longstanding home for families in need. The love for one’s neighbour is evident here in Mexico through the outreach into the local community and is inspiring for all those involved with the program. I am keen in the coming years to watch how the homebuilding continues to evolve as Project Mexico transforms both the lives of families and the greater community.
For more information on Project Mexico, please feel free to view their website. Additionally, donations to the Orphanage are always welcome and enable a continued home for the boys. Options for giving range from supporting the boys education and ongoing support of basics, to stocking the pantry and gifts at Christmas.
Supporting the Tijuana Community
With the blessing of EnergyLink, I’ve been able to take a few months off my normal work duties to volunteer overseas. I’m currently a couple of kilometres south of San Diego and the US border, in Baja California, Mexico. In a coastal town neighbouring on Tijuana, we’re based at Saint Innocent’s Orphanage from where Project Mexico runs much of its practical operations.
In Mexico, stop and yield signs are mostly suggestions, road rules are lightly enforced, and roads themselves are made of potholes. Yet interestingly, I feel safer riding around in the bed of a pickup truck than driving around in Australia or the US. People are more attentive and quite patient with other road users and pedestrians, despite frequent traffic. Instead of an obsession with being in the right, drivers are more concerned with avoiding accidents, it just happens to look a bit chaotic along busy roads and intersections. Another impressive dynamic has been the nearly seamless use of both Mexican Pesos and US Dollars side by side, with almost all businesses accomodating both currencies in this city neighbouring the US.
The ranch is a place full of joy with a loving environment for the boys who live here, the staff, and volunteers who visit. There are 10 ranch dogs here, each with their own personality; there’s Momo and Gala, Cosmo and Riley, Anthony, Nyssa, Sochi, and Max, and my favourite ranch dog of all, Roo. Funnily enough, he looks a bit like a kangaroo, with a straw-coloured, short-haired coat, and a scrunched kangaroo face. But as a silly guy, he loves to cause us grief by running out in front of our trucks and cars when we’re driving around on-ranch.
It’s been fun bunking in the intern housing. The 15 of us interns play host to the volunteer groups that come through from parishes all across the United States and help ensure that all operations run smoothly through the Summer. Each group stays for seven days, including four build days, a rest day, and arrival/departure days. When we’re not building or preparing for new groups, there’s downtime to play sports with the boys, whether it’s soccer, basketball, frisbee, volleyball or Capture the Flag. We’ve also spent a few days off-ranch with trampolines at Flyers, splashing around at the waterpark El Vergel, helping at the local soup kitchen Desayunador, bushwalking in the mountains at sunrise, and relaxing at the beach. I even had an opportunity to be a guest speaker about Australia as it fit into an English lesson for the older boys here.
Summer 2017 marks the start of a new house design, an update after 28 years of a wood-based house frame. With the new design it’s been great to provide some input on improving the process of building as we work out the kinks and make tweaks. Our new design allows us to provide a larger shell, with greater potential and options as the family molds it into their home. Occasionally, we’ve been able to see how families have customised previous builds, whether through paint choice, tiling, interior walls, insulation, electricity and plumbing, or extending the structure for added space.
Providing a shell rather than a completely furnished home allows us to focus on providing a quality build: secure, safe, and watertight. At the same time it encourages the family to take ownership in making it their own, establishing a partnership effort rather than a handout.
Here in the Tijuana region, wealth disparity and poverty is evident with people living in makeshift housing and occasionally juxtaposed with a house that looks like it was taken from a Sydney suburb. Streets are often lined with half-built homes or businesses, and frequent abandoned buildings. One of the largest poverty challenges lies in the conditions for renters, with what appears to be slumlording at its worst. Rental homes might leak terribly, subjecting the tenants to unhealthy conditions of mold, fleas, and illnesses especially during the rainy season. The landlords refuse to fix issues such as leaky roofs nor allow the tenants to make any modifications themselves due to superstition. Coupled with low wages, rent, and land payments, families struggle to make ends meet while often trapped in tough to escape situations.
Much of what Project Mexico strives to do is improve the lives of people stuck in these situations, by providing them with a jumpstart. At the same time, it’s building empathy and love in the groups of volunteers who come to help their southern neighbours by expanding their perspectives and experiences.
At many of our homebuilding sites, we’ve been treated to a humbling experience of being served by those we aim to help, through their expressions of hospitality. The families have prepared delicious homemade meals of burritos, gorditas, fried chicken, and pizza, alongside generous refreshments and fruit, a gesture of kindness and great expense that they likely cannot afford but nonetheless important for them to express.
With the building process, there are some really interesting aspects and points where attention to detail is important for ensuring that the house is put together with structural integrity and a good watertight seal. In the follow-on article, I’ll go through the updated design, build process, and details that I’ve found most interesting.
For more information on Project Mexico, please feel free to view their website. Additionally, donations to the Orphanage are always welcome and enable a continued home for the boys. Options for giving range from supporting the boys education and ongoing support of basics, to stocking the pantry and gifts at Christmas.
Choosing Optimal Settings to Heat and Cool Your Spaces
With all the available settings for heating, ventilation, and air conditioning (HVAC) systems, it might be confusing to work out the best way to keep occupants comfortable while minimising electricity costs. We’ll explain some of the most relevant terms, settings, and the potential savings that are up for grabs by tweaking these to match the application.
The background and advice given in this article mainly encompass knowledge of the HVAC&R Nation Skills Workshop: Set Points and Control Bands, a publication of the Australian Institute for Refrigeration, Air Conditioning and Heating (AIRAH).
Why Adjust the Settings?
Currently, common practice across commercial office buildings, shopping centres, and public facilities is to keep set point temperatures at 22-22.5°C with narrow control bands, for the entire year. This presents a large potential to improve thermal comfort alongside energy efficiency by tweaking the settings to fit the purpose.
Did you know that changing the set point by 1°C can reduce its associated conditioning energy usage by an average of 10%? General optimisation of the settings can mean immediate savings of up to 20% of the HVAC services. Doing so can cut down on issues such as heating and cooling conflicts between base building and tenant systems or between adjacent mixing boxes and air outlets.
These optimisations can be applied against a variety of equipment sizes, for split, package, and small room a/c systems found at smaller sites, as well as typical commercial buildings with more complex, centralised HVAC systems incorporating chillers, AHUs, FCUs, and VAVs. These can incorporate small wall or remote control thermostats as well central Building Management Systems (BMS) with greater control programs and relays.
The 3 most important controls affecting both thermal comfort and efficiency are the temperature set point, the dead band, and the proportional band.
- Temperature set point: The target temperature for a space to be maintained by the HVAC system.
- Dead band: The range for which neither cooling nor heating is required. By widening the dead band, there is a greater duration where neither heating or cooling occurs.
- Proportional band: Also known as throttling range, it is used for modulation control of the HVAC system. By widening the proportional band, the system is able to run at less than full capacity more often.
Seasonality and Adaptive Thermal Comfort
By considering adaptive thermal comfort, which is to say that humans naturally acclimatise to higher Summer temperatures and lower Winter temperatures, then space set point temperatures should also vary accordingly. Recommended comfort ranges which also provide decent energy efficiency are given as:
- Winter: 20-22°C
- Summer: 24-26°C
A set point for a space would be chosen between the above ranges, along with a dead band to cover the space between the regions, and a proportional band to keep it within the region of comfort while heating and cooling. For example this might mean a set point of 23°C, 2°C dead band, and 1°C proportional bands.
More application specific examples are discussed with more detail in the relevant section below.
Good communication between the facility managers and staff/occupants/customers is especially important while optimising the HVAC control settings, as this enables cooperative progress in selecting them appropriately. This minimises the main risk of an increase in comfort complaints if input is taken initially and feedback is closely monitored during the exercise.
Temperature steps of 0.1°C are best for fine tuning system efficiency, so consider how well your controllers and sensors are able to provide for this flexibility. The temperatures at the edges of the control band also need to be considered for their comfort levels when optimising each space.
Application Specific Advice
For offices and similar purposes, good efficient settings would be a set point of 22°C, a 2°C dead band, 1°C proportional heating band, and a 2°C proportional cooling band. This has been graphically displayed below to provide a visual understanding of the HVAC settings.
The above office example might be stretched for further energy efficiency targets with settings such as 23°C set point, 3°C dead band, and 2°C proportional bands.
For transient spaces encompassing food courts, malls, foyers, and shopping centres, requirements for heating and cooling can be significantly relaxed. Appropriate seasonal bands are 16-18°C in Winter, and 26-27°C in Summer. Implementing such a control strategy translates into savings of up to 50% compared with optimising the same space for office work.
Additional Methods for Improving Occupant Comfort
- Increasing the air movement in the building helps to reduce the apparent temperature. Options such as openable windows and ceiling or desk fans increase feelings of comfort when it might otherwise feel too hot.
- The ability to open windows, turn on a fan, or adjust a thermostat also gives a feeling of control to tenants and thus allows for toleration of a wider range of temperature levels.
- It’s important to monitor humidity to ensure it doesn’t get too high, and integrate a dehumidifier component to better balance thermal comfort and air quality.
- Encouraging staff to dress appropriately for the season can mean savings of 10-15%.
When making changes, ensure there is a good feedback loop between facilities managers and space occupants to work together in achieving a good balance. Make gradual, periodic adjustments by 0.3°C while monitoring the feedback to allow occupants to acclimatise to the changes and minimise the perceived impact.
Your specific settings may vary, as there are a number of variables to consider for each particular space, but these recommendations remain a good reference point to work from regardless.
General variables for consideration:
- Building envelope: The effectiveness of walls and windows in terms of insulation and natural ventilation.
- Type of air distribution: Is air distributed evenly or are some occupants more directly affected by the air outlets?
- Types of occupants: What is the dress code like and culture towards energy efficiency?
If you’re having trouble with equipment consistently delivering the desired settings, consider the types of controllers being used, which cover P (Proportional), I (Integral), and D (Derivative) to match to the system needs. P works most efficiently for stable systems, while PI can be used to reduce offset problems, PD to reduce overshoot issues, and PID to overcome both. For more information on controllers, the AIRAH publication goes into greater detail.
For more information around general HVAC recommendations, maintenance, upgrades, and troubleshooting, please see our article on Running HVAC Systems Effectively.
Dealing With Complaints
Once settings have been optimised, changes to set points and bands should be a last resort. Some of the checks to be carried out following a complaint are given below:
- Spot check and log space temperatures
- Check control valves and damper positions
- Review the air flow, heat load, temperature sensor locations, and air outlets with respect to the complaint location
- Review the units supplying the area for any conflicts such as from base building against tenant units
Power Factor Correction Overview
Power factor correction (PFC) units are quite common across medium and large commercial sites. In this article we’ll first summarise power factor and then share some recommendations for power factor correction to help you decide what’s best and how to troubleshoot issues.
Power Factor Summary
Power Factor (PF) is the ratio between 0 and 1 of real power (kW) to apparent power (kVA). A low PF can be introduced by a large quantity of reactive power loads on site such as air conditioning, pumps, or industrial equipment.
In an analogy for apparent power, a latte is made up of two parts: coffee and froth. While a bit of froth is ok, when there’s too much you’re getting less coffee, in the same way that you could be paying too much for your apparent power when the site’s reactive power is too high. The larger the reactive power, the lower the power factor.
A low PF can have an impact on the capacity portion of your electricity bills, leading to higher charges than may be necessary. It also is a form of site inefficiency that affects the electricity network and your on-site equipment. For more detail on what PF is, as well as why and when it’s important, please read through our Power Factor Overview Article.
Power Factor Correction Benefits
A PFC unit is designed to help offset the reactive power loads that are on site. In a physical sense, it is basically a bank of capacitors that acts as a buffer between your site’s equipment and the electricity grid, sitting in the main switchroom when there’s space.
- When tariff appropriate, saves money off your electricity invoices
- Helps to reduce strain on the network’s physical infrastructure
- Reduces equipment failure issues with improved power quality
- Improves voltage stability to eliminate operational difficulties with processing equipment
Should I Get a PFC Unit?
If you answer yes to many of these questions, then it is worth looking into.
- Is your network tariff appropriate? Yes, if KVA appears on your electricity invoices.
- Do you have a low PF? Yes, if your PF is often less than 0.85 during peak periods.
- Is your site’s electricity demand large enough? Yes, if your demand is often > 150 kW during peak periods.
- Do you have much reactive power equipment on site? Yes, if plenty of inductive equipment.
- Do you frequently experience electrical or mechanical equipment failure?
Joining the PFC Club
Make sure to choose a reputable supplier and installer. There’s nothing worse than having a problem with your unit 14 months in, only to discover that the company has gone under. Some grid networks have a register of installers (see section below) or offer PFC services themselves. Also, ask peers in your industry for recommendations.
The supplier and installer will be able to provide you with a quote on the right sized unit for your site. They should also provide you with an expected payback timeframe based on the conservative savings. Within a few years is typically a good timeframe for payback. Units are rated based on reactive power needs (kVAr).
Estimated costs are usually around $70/kVAr for low voltage and $150/kVAr for high voltage. Costs can increase for added requirements such as limited switchroom space, enclosure cooling, and harmonic filtering. Features such as controllers to scale capacitors with the varying site power demand will increase costs compared with static PFC capacitors. Similarly, to cope with non-linear loads (e.g. computers and variable speed drives) that exceed 15% of site totals, a de-tuned PFC will double costs over a standard PFC.
Looking After Your PFC Unit
Annual servicing for units is typical, or six-monthly if located in a hot or dusty location. Ongoing testing and maintenance ensures that units continue to operate effectively, provide the right level of correction, and facilitates budgeting for expected future component replacement. This also helps to uncover issues ahead of incidents that could inadvertently affect the capacity charges that you pay.
Is My PFC Unit Performing Properly?
Since you’ve made a significant investment in the hardware to improve your PF, it makes sense to validate that it’s working from time to time. Fortunately, you can use EnergyLink to view your site’s power factor performance during peak times of equipment operation. Naturally, when the inductive loads are switched off, the PF will typically return closer to 1.
Below are two examples of sites with poor PF during daytime peak periods, despite having PFC units on site.
Resolving PFC Issues
If your PFC unit doesn’t seem to be operating optimally, get in touch with your supplier/installer for advice.
It might be time for testing and servicing, which may lead to uncovering control issues or worn out components needing replacement.
Your site’s electricity demand may have outgrown the capacity of the unit. To address this, the capacitor bank may need to be expanded or additional demand management options, as in references, could be explored.
PFC Providers & Installers by Network
Additional Strategies to Reduce Demand Charges
Understanding Power Factor
Power factor is a term used frequently in the energy industry, but you may be looking for more details to understand exactly what it is and why it’s relevant. We’ll go through the whats, whys, whens, and hows in this article to try and clear things up for you.
What Is Power Factor?
Power Factor (PF) plays an important role in your site’s power quality. PF gives an indication of equipment on site requiring magnetic and electric fields for their operation.
PF is affected by the amount of reactive power on site, most often by inductive loads such as pumps, fans, motors, air conditioning units, and other heavy machinery. Specifically, PF is the ratio between 0 and 1 of real power (kW) to apparent power (kVA), where 1 is optimal.
In an analogy for apparent power, a glass of draught beer is made up of two parts: liquid beer and head. While a bit of head is ok, when there’s too much you’re getting less beer, in the same way that you could be paying too much for your apparent power when the site’s reactive power is too high. The greater the reactive power, the lower the power factor.
Why Is It Important?
A low power factor can have a big effect in how much you pay on your electricity bills.
Demand or capacity charges typically make up a large portion of your electricity costs already, as a result of the major impact that it has on upkeep and upgrades of the electricity grid. For more general information on demand, please read through our article on Understanding Electricity Demand.
Sites with low power factor due to high reactive power requirements place a greater strain on the electricity grid. This is because these requirements has a direct effect on the physical infrastructure, requiring a larger pipeline to deliver power to the site.
When Is It Important?
For larger customers, the network costs of maintenance and supply to customers with high reactive loads are reflected on the network portion of electricity invoices, via a $/kVA/day rate. PF is usually ignored for small customers who just pay for kWs, which is why its important to see if kVA appears on your invoices to see if it’s relevant.
If you’re paying for kVA, next it’s good to look at your site’s typical demand magnitude. On your invoice, make sure the average capacity charge is at least 150 kVA. A good payback will be achieved when a high demand is combined with an existing low power factor. The invoice may also specify the peak periods for the network tariff.
It’s important to keep in mind the time of day when looking at PF. Your particular network tariff will specify the time period when peak demand/capacity is calculated. For example, many Ausgrid tariffs take the highest demand experienced between Mon-Fri 2-8 PM for their capacity charge. Anything seen outside of these times is irrelevant for PFC savings in this network.
Use EnergyLink to Check Yours
From within EnergyLink, within the Analyse Data page, you can choose to view Power Factor from the measurement points menu for the selected meters.
While the first example shows a well-performing site, the low PF of the second example indicates that it could be a good candidate for a PFC unit. More information can be gained by looking at reactive power to quantify the reactive power loads on site.
Power Factor Correction Summary
A power factor correction (PFC) unit is used to improve your site’s energy efficiency by offsetting the reactive power loads on site. Using a bank of capacitors, the electricity network is buffered from the site’s equipment.
A PFC unit can help to reduce your electricity charges when tariff appropriate, as well as boost site energy efficiency to reduce strain on the electricity network and the site’s equipment.
For more on PFC benefits, recommendations, and troubleshooting, please stay tuned for our upcoming Power Factor Correction Article.
Spring Cleaning for Your Electricity Usage
With the time of Spring cleaning amongst us, why not declutter your electricity profile and get it into efficient shape for Summer? With a few tweaks, maintenance to A/C and refrigeration, as well as planning possible upgrades, you’ll feel confident that your electricity bills will stay as low as possible through the hot weather season.
As a general rule, the best profile to aim for has a visible daily peak in consumption during operating hours and quickly returns to a minimum electricity demand outside of these hours. A low out of hours demand can be achieved by setting schedules for lights and A/C according to posted operating hours or to when most staff or clients are on site.
The overnight load should be as low as possible, by switching off all non-essential equipment such as lights, A/C units, supply and exhaust fans, pumps, and infrequently used refrigeration. Examples of essential equipment might include IT cooling units, emergency lighting, minimal security lights, cool rooms, fridges, and pokies.
So, What’s Being Left On?
Clues about the type of equipment that runs out of hours can be gathered from the electricity profile. It can be any combination of lighting, HVAC peripherals, A/C electric heating, irrigation pumps, refrigeration, or miscellaneous appliances. A large out of hours demand could imply many of these as combined suspects. For detailed example profiles of what each equipment type looks like, please look through the precursor article on What Makes up an Electricity Profile.
At places such as bars, pubs, and clubs, operating hours will vary widely by the style and area in which they operate. However, the equipment on site will be fairly similar, containing A/C cooling and heating, HVAC peripherals, cool rooms, various appliances, and pokies. Generally speaking, these sites should scale pretty consistently in usage according to their floor size, where benchmarking will help to point out obvious outliers in energy performance.
An example tweak might be turning off cool rooms and glycol systems that are only used on weekends to reduce their consumption and increase their lifetimes. Additionally, using schedules to control A/C units will help to reduce equipment runtimes. Utilising natural ventilation and lighting where possible during cleaning, and/or providing mechanical fans will also reduce unnecessary A/C equipment usage.
Other improvements to the profile would be using equipment schedules to ensure consistent operation. If the site stays open 24/7, isolate which areas need to stay open for the size of patronage and turn off equipment servicing other sections to minimise what runs.
These sites tend to have standard office hours to which equipment can be set providing great potential for consistent daily profiles. Schedules should follow the hours in which most employees/tenants are on site to reduce requirements for central A/C. If A/C is required after-hours, push button timers can be a good compromise by providing extra comfort while reducing equipment use.
Due to the consistent nature of these buildings it can be easy to spot from the main meter alone where A/C equipment runs to incorrect schedules or to quantify the amount of lighting. The overnight demand should be as close to flat and zero as possible. Many office buildings operate 5 days where weekend profiles should match typical out of hours behaviour.
Demand Management for Pumps & Irrigation
Pumps on-site for purposes of irrigation at golf clubs, for bulk liquid terminals at a port, or used with pool systems can create large demands in electricity. Depending on the meter network tariff, these demand spikes can have a large impact on electricity costs and how often there is an opportunity to reduce the capacity portion on invoices. As an example, Ausgrid Network capacity tariffs are set by the highest recorded demand during peak times of Monday-Friday, 2-8 PM for a 12 month rolling window. As a result there are big opportunities to control your invoices by managing the times at which your pumps run, but needs to be done consistently to achieve a reduction.
This highlights a specific need for demand management, but is generally applicable for most large market customers. Managing your demand is another way of keeping your electricity profile consistent and avoiding unexpected high charges. For more information, the relevant article on Understanding Electricity Demand delves into greater explanatory detail and options for mitigating capacity charges.
Benchmarking is a great way to see how your site stacks up against others in a portfolio and the industry. This is a quick way of identifying target sites that are underperforming and can give you an idea of on-site inefficiencies depending on the time of year analysed.
Upgrades are good considerations for improving your electricity profile, but it is important to prioritise where the budget goes. Starting with LED light upgrades for areas running frequently or even 24/7 provides reductions in demand and consumption while providing a quick payback.
HVAC, as a large portion of site usage is another good target. First try to address inefficiencies via tweaks and preventative maintenance, and secondly consider replacements depending on the age and type of technology. Please read through the related article on Running HVAC Systems Effectively for operational advice, maintenance tips, and when to upgrade.
Refrigeration systems which run 24/7 are another source of consistent energy use. Improvements can be made with simple maintenance procedures, small upgrades, or replacements when necessary. A related article on Looking after Refrigeration runs through how to get the most out of your cool rooms and fridges from operating procedures and basic owner checks, to quick, easy upgrades and professional maintenance visits.
Sometimes achieving a minimised, flat out of hours load may require detailed investigation to uncover the equipment that is running. Often, schedules and controls could unknowingly be switching equipment back on overnight. An after-hours walkthrough to discover these anomalies is well worth the time by uncovering issues that waste thousands of dollars per year. Hints from the profile will help to identify the sorts of equipment to look for.
Your electricity profile might create quite the list of action items that you might not have time for as site manager. In this case, an electrical contractor who is familiar with the site might be just the person to manage this task list. You might also consider empowering maintenance providers with energy efficiency targets to broaden their approach to a proactive one rather than a reactionary one. These are a few complementary methods to implement preventative maintenance and uncover underlying issues.
How to Read your Profile for A/C, Lighting, Pumps, Fans, Heating, and Refrigeration
The various types of equipment on site make up the electricity profile that you’ll see for your particular site. The large variety of equipment types and add-ons can create complexity in the profile, making it difficult to decipher what is happening at a site like the example below.
Understanding the basics for each equipment type will help identify what you’re seeing in your profile and then to optimise the various components to run most efficiently. This profile will most commonly be composed of any combination of lighting, HVAC peripherals, A/C, electric heating, irrigation pumps or refrigeration, in addition to site particulars such as other kitchen or industrial equipment. The following sections outline typical example profiles exhibited by their equipment types.
Lighting without sophisticated controls is easily identifiable by a flat, consistent profile during on periods.
HVAC peripherals such as pumps and fans also tend to have flat loads that are continuous while running. If more sophisticated controls such as VSDs, VAVs, or VRVs are installed, then these loads will vary rather than just on/off or indexed stages.
A/C units produce more fluctuating profiles as they service large areas and are greatly influenced by variables such as service area, space heat loads, external temperature, and air changes.
Electric heaters are energy intensive and can often be easily seen on the main meter when turned on collectively due to the large demand. They correlate well with temperatures, often seen used on cold evenings. As these tend to be manually controlled it can be easy to leave these running overnight incidentally.
As these are highly inefficient and can also spike demand to increase capacity charges on your invoices, it is recommended to avoid their use. Consider alternative gas powered heaters for external use instead.
Refrigeration loads on most sites are smaller than A/C as they condition smaller spaces. They still have higher daily demand over their out of hours use, but with smaller magnitudes and less variability.
Putting It All Together
Now that we’ve looked at some typical equipment profiles, the next step is identifying the various equipment in your own profile. This is especially useful when looking to achieve a consistently low out of hours load or identifying a new load that appears in your profile. Knowledge of the equipment on your site will also substantially help you to identify these individual loads.
For more on using this new knowledge to improve your site’s performance, be sure to read through the follow-on article, Crafting a Clean Electricity Profile.
As a part of the recent Sydney Design Festival, there were a number of sustainability themed events. One of the ones I was able to attend was hosted by the Greenhouse at the Powerhouse Museum.
At the outdoor cafe downstairs of the Powerhouse Museum, this event filled up quickly with people interested in the evening’s topic. The overall theme surrounded future impacts of climate change on Sydney and approaches within architecture, urban planning, and engineering to adapt to the challenges. Each of the speakers first gave a short talk on their topic, followed by a panel Q&A led by the MC Tina Perinotto.
Hudson Worsley from Presync spoke about his experience with the City of Sydney in preparing Adapting for Climate Change – a long-term strategy for Sydney. Pointing to the Opera House which has been around for 55 years and become deeply iconic as part of Sydney’s image, this strategy looks similarly as far into the future to 2070. Amassing this effort involved consultation with 37 stakeholders across business, government, and utilities as well as a 23 person Citizen’s Panel. Highest risks for the future included increased heat levels, greater rainfall, more droughts, and higher prevalence of bushfires and associated air pollution. Discussed in the plan are ways to adapt to these impacts at short timeframes to 2030, medium actions out to 2050, and long term strategies looking to 2070.
Expected dramatic increases in extreme heat days & rainfall events, from the City of Sydney Strategy
Andrew Thai from Frasers Property spoke to building sustainability features into new architecture, exemplified by 1 Central Park with a focus to regenerate, not just reduce. While this example delivered a premium priced product, the lessons can now be taken and applied to more practical ventures for widespread impact. He also noted a change in tide where tenants now come to them with sustainability interests rather than having to search high and low for occupants to fit the bill. This has also started coming through in industrial and manufacturing sectors, affording them the opportunity to supply sites with best practice from the start to these customers.
Dr Jan Golembiewski with a background in both architecture and neuroscience shared simple samples of greenery throughout our society of good and healthy spaces to when green can become toxic. Positivity emanates from green spaces where there is potential to interact and engage with our senses. Negativity comes into play when such areas are artificial or beyond interaction such as viewed through a car window along a highway while one is stuck in traffic. The focus was to integrate plants into everyday life, create public community green spaces that engage and rejuvenate, provide quick, easy access to bushlands, while cutting down on sprawl that uses greenery to push people further apart.
Lisa Mclean from Flow Systems, who were also involved on aspects of the Central Park effort, discussed a future where local sustainable solutions displace the relevance of traditional utilities. Instead of requiring large infrastructure, communities become water and energy positive enabled by innovative technology. In such a world with a focus on self-sufficiency and community, entities like utilities and networks would have to reimagine themselves.
Especially highlighted by Hudson, the theme of interdependence of all domains was at the forefront concerning climate change. Its effects don’t only impact one area, but translate across industries from one to another, whether directly or indirectly, in small or large ways. This furthers the need for vision, strategy, and action beyond short-term political cycles, in order to adapt to these upcoming risks by working together.
Another interesting discussion point was in rethinking urban design. Rather than every home having its own artificial nature in the form of a manicured garden, pooling these spaces together through apartment living means space for real nature where animals can also live and thrive naturally. This approach also brings community together, an important aspect for happiness, in addition to reducing sprawl to reduce commute times and traffic congestion.
Keep Your HVAC Systems Operating at Their Best
Basic Operation Overview
Heating, ventilation, and air conditioning (HVAC) equipment come in various forms such as ground or air-source heat pumps, air or water cooled towers, chilled beam cooling, and radiant cooling/heating, to name a few. Most systems operate on the same principles and cycles, but technology specifics differ for condensers, evaporators, and compressors. These differences simply change the method in which heat is absorbed, compressed, and released, along with a corresponding difference in system efficiency. A good reverse cycle air conditioning system can provide both cooling and heating in locations with a mild climate.
Starting with a run through of system basics will help understand how best to run them optimally and what can be done to improve their operation. Having much in common with refrigeration systems, a reverse cycle A/C system consists of four main components; an evaporator heat exchanger (HX) for providing cooling to the space, a compressor to push the warmer refrigerant to a higher pressure, the condenser HX where it releases heat to the non-conditioned outside space, and an expansion valve where the refrigerant passes through to lower pressure on its way back to the evaporator.
For more details on the vapour compression cycle visit the quora page.
General Operational Recommendations
A/C usage makes up a large portion of your electricity costs, so it pays to make sure you’re doing the most you can to keep it running smoothly and efficiently, while maximising lifetime.
Keep HVAC turned off as much as possible during shoulder seasons and avoid situations where both heating and cooling are running simultaneously. During this period of time, make use of natural cooling methods such as open windows supplemented with mechanical fans.
Using A/C in areas open to the outdoors keeps units running continuously, which drains on electricity and increases equipment wear.
Schedule equipment using a building management system (BMS) or programmable thermostats to match operating hours and avoid unnecessary usage overnight. For hospitality, adjust schedules and set points according to the needs of customers rather than staff.
Run A/C only during normal operating hours and not for minimal staff occupancy. In such a case as for cleaners or early arrival/late stay of employees, instead make use of mechanical fans and natural ventilation/lighting. This will significantly reduce energy requirements on site, reduce maintenance requirements, and extend equipment lifetime.
Utilise metering and monitoring on A/C systems as a way of identifying when loads are operating abnormally, out of schedule, and to verify that best practice is being followed. Even viewing main meter data benchmarked against other sites in the same industry can give a good idea of good or bad A/C performance.
Maintaining Your System
A good maintenance strategy is key to avoiding hidden issues over time which degrade energy efficiency. This means regular, thorough, preventative maintenance, not just service calls in response to occupant complaints. The latter category these often results in quick comfort fixes at the expense of higher ongoing energy costs.
Preventative maintenance might be cut during budgeting exercises, but cutting corners on HVAC equipment is a short-sighted approach that often leads to concealed, costly issues. Examples include faulty chilled or hot water valves which result in simultaneous heating and cooling, a costly method of maintaining set points as the heating system fights against cooling. Variable speed drive (VSD) sensors can fail and prevent fan speeds from changing to deliver the savings expected from this technology. Variable air volume (VAV) mixing boxes can go out of calibration resulting in freezing conditions, fixed by enabling continuous use of reheat systems (e.g. electric duct heaters) even through Summer. When a maintenance services provider is called out in response to diminished cooling and heating capacities, they may bypass time clocks to keep the plant operating out of hours to try and meet the required set points.
To get the most out of maintenance providers, they should have incentives not only to “put out fires” highlighted by the end user, but be empowered to look further underneath for underlying issues affecting energy and water wastage. It’s important to ensure that A/C units continue to deliver close to their stated cooling capacity rating in both flow rates and temperatures.
This means collaboration between the facility manager and the contractor in understanding the assets, considering the age and type of equipment as well as controls and settings available such as a BMS. The building owner should also be aware of the need to allocate resources in order to implement high-performance maintenance to transform a neglected building or retain environmental certifications. For a more detailed look at the whys and hows of implementing effective maintenance strategies, see pages 14-15 of the AIRAH’s HVAC best practices.
To achieve the best outcomes, responsibilities for involved parties such as the facilities manager, building owner, occupants/tenants, and the maintenance provider are outlined on pages 23-26 of AIRAH’s best practice manual.
Upgrades & Considering a New System
Stay aware of governmental incentives which may help to help offset costs for upgrade projects. Metering on your HVAC equipment first lets you see the current consumption of your units, guide which improvements to make, and then to track savings achieved by initiatives.
Once equipment has become inefficient, obsolete, and unreliable due to age and/or use, it becomes likely that it will be more cost-effective to replace than continue to run. New systems bring with them modern technologies across the board for vast improvements in efficiency of heat exchangers, compressors, refrigerants, system design, controls, settings, and other efficient peripherals to tweak the system. Advancements include VSDs on compressors, high-efficiency motors, pumps and fans, pipe insulation, electronic expansion valves, improved heat exchanger design for condensers and evaporators, fault detection, and alarm systems. Read more about variability upgrades in the relevant article, Efficiency Tweaks for Your A/C, covering VSDs, VAVs, and VRFs.
Upgrading with VSDs, electronic expansion valves, insulation, and heat exchangers boost efficiency
While many of these advancements are available as drop-in upgrades, replacing out-of-date units in their entirety will provide better efficiency increases in a more cost effective package. This is especially true for the long-term where existing systems are more than 15 years old or still use R12, R22, or R502 refrigerant.
More important factors to consider when maintaining, upgrading, or replacing various aspects of HVAC systems such as AHUs, chillers, boilers, VAVs, pumps, BMS, etc are discussed in greater detail on pages 36-60 of AIRAH’s Guide to Best Practice Maintenance & Operation of HVAC Systems for Energy Efficiency.