The damage condensation can cause goes beyond just making a surface feel unpleasantly damp. Moisture in an unwanted space may cause rust or rot to the building materials, or encourage the growth of mould & other related allergic or respiratory issues. Also, apart from a minority of extreme climates within Australia that are always too cold or too hot, condensation can come from both directions – both outside and inside, so to speak. Because you can’t control the weather to eliminate it completely, the next best option is to understand the risk and effectively manage it. To properly manage it though, you need to keep in mind that if a building’s surface isn’t “airtight”, moisture will travel with the air through not just any gap or hairline crack but also any permeable surface. And just to give you an idea of how this can happen in unexpected ways, standard indoor plasterboard & normal interior paint are both permeable – that is, water vapour will slowly pass through both of them!

The most damaging form of condensation is unseen or “interstitial condensation”. This is found between building surfaces, inside walls & within roof spaces – places not designed to become damp. Unnoticed & untreated, moisture may start to build up, eventually causing extensive damage to the building’s internal structure requiring costly repairs.

How can you Prevent or Manage Condensation?

There’s three main ways to manage moisture & prevent damage inside a building:

1. Separation – Keep the humid air away from cold surfaces with an air-tight barrier, or try to separate any obvious water vapour from vulnerable, porous surfaces.
2. Warming – Increase the cold surface temperature to above the dew point. This can usually be done with insulation or by controlling heat transfer through the building.
3. Drying – Use extractor fans to increase ventilation to the area to help evaporate any moisture. This can sometimes be done through purely passive means, but fans will deliver more airflow (more than even an open window can).

Can an Air-Tight Building Prevent Condensation?

• Will improved sealing reduce condensation?
  Adding a layer of Separation can help, because less air will be passing through the building’s surfaces. However, if moisture permeates the structure through any other means it won’t completely eliminate it, because improved sealing doesn’t help with warming or drying.
• Can sealing the building on the inside reduce humid air entering the walls or roof-space from outside?
  In short, no. Bathrooms are normally sealed on the inside better than usual as they’re a special high-humidity case, but even this isn’t normally perfect. A well-sealed building envelope will minimise humid inside air entering the walls and ceiling through infiltration, but is not likely to reduce humid air permeation, from outside or inside.
• Can a building that has fewer & smaller air gaps reduce the permeability of water vapour through building surfaces?
  A “tighter” building won’t reduce the likelihood of condensation from humid outside air or by permeation from humid inside air if the building materials themselves are still permeable, so it depends on what building materials are used. In fact, sometimes this can offer reduced drying from reduced airflow between building surfaces, which can actually make things worse.

Can Improved Building Energy Efficiency Reduce Condensation Risk?

It all depends on the materials the building is made from plus how the building is designed & constructed. Things like increased insulation can definitely help with warming, but using the wrong products (or even the right products installed the wrong way) can end up making things worse. At the end of the day though, many of the techniques designed to combat condensation can also be used to increase the building’s energy efficiency, so it’s all up to how well the building is designed. For more information on this topic, we recommend the Australian Building Codes Board’s handbook Condensation in Buildings for more information.

If you’d like more information about how to improve the energy efficiency of your building, contact us for a free fee proposal!

The post Condensation & Humidity: How to Control it in your Building appeared first on Anderson Energy Efficiency.

The Building Surveyor had just inspected the building for final occupancy. However, they had noticed that the Energy Efficiency Report done (12 months earlier) listed reflective-foil roof insulation. An awful discovery found that there was none installed on the building!

The builder was still on site, but construction was nearly finished. The roof scaffolding was scheduled to be removed on Friday, so any actions had to be figured out & performed quickly.

What could they do?

Should they take off the roof, add the reflective foil, then replace the roof – an incredibly expensive & time-consuming task? What else could they possibly do?

Could Anderson Energy Efficiency help?

In situations like these, you need someone with a bit of experience and a deep understanding of legislative & regulatory requirements.

Luckily for the client, the Energy Efficiency Report had miscalculated the amount of added ceiling insulation to the roof-space. The requirement called for R2.5 total (roof+ceiling); this was translated to R2.5 to the ceiling in addition to foil under the roof. However, we found that the required amount of added ceiling was much less (only R1.8).

Long story short, we were able to calculate the difference in heating energy and cooling energy between the ‘as-built’ dwelling & the simulated “complying” building. We demonstrated that the building as constructed had lower heating energy and lower cooling energy, and therefore was better than the “complying” design.

The client was delighted that they had a design that complied with the requirements. Even more so, because they didn’t have to spend any more money on the roof! More than that, the builder’s schedule was not delayed by this mix-up and the home was ready for occupancy on time.

They were also pleased that the investment in our professional consulting was a fraction of the alternative cost.

If you have a building that is “just not right”, or feels uncomfortable to live in, we can give you an opinion.We have the expertise to tackle tricky building thermal comfort problems, that may be otherwise costly to remedy.

Contact us to see how we can help you!

The post Missing roof insulation?! appeared first on Anderson Energy Efficiency.

At Anderson Energy Efficiency, we’ve assessed thousands of houses & units, so we’re quite skilled at knowing how & why some buildings can get so hot while others seem pleasant all year around. So we’ve put together some helpful tips to be energy efficient while keeping your home cool in summer!

1. Throw Out Some External Shade

The first solution to overheating is to keep the summer heat out. Ideally, you want to be controlling how much sunlight is heating your home, which is much easier said than done. The first (and easiest!) step is minimising the amount of sunlight that hits any glass windows or doors. One way this can be done is by installing external shade in the form of fins, blades, lattice, awnings, outdoor blinds or external window decals. Try hanging tightly woven screens or bamboo shades outside the windows during the summer. Even large potted plants & vegetation can provide an aesthetic measure of external shade. Anything that minimises how much sun goes through your glazing!

2. Block the Summer Sun

By applying a strong solar-tint film to your glass, you can control the amount of solar heat coming through the glass. Choosing the right tinted film for your glass (such as a heavy tint with a Solar Hear Gain Co-efficient less than 0.30) could reduce a room’s cooling bill by 30% to 50%, depending on which direction the glass is facing. When deciding which windows are more important, remember that East & West facing glass lets more heat inside than North & South facing glazing. If tinted film isn’t an option for you (for instance, if you’re renting), you can try other methods of blocking out the sun.

3. Cover Your Windows

Even on a low budget there are still some super cheap options available for extremely hot windows – for instance, taping a layer of bubble-wrap to a window isn’t the prettiest but it’s a cheap way to make a window perform as if it was double glazed, and placing a car windshield reflector on the inside of your window will reflect most of the sun’s rays. And while either of those options certainly aren’t as pretty as window tint, they both have the added bonus of acting as partial sound absorbers too!

4. Consider Your Curtains

Another way to affordably reduce solar infiltration is by adding internal block-out blinds or curtains. These are special blinds with a white or reflective outer surface that bounces back unwanted radiant heat. Heavier blinds or generous drapes have a higher R-value, meaning they’re better insulators. The closer the curtains are to the window the better, since any gap between the glass & curtains will hold hot air that slowly leaks through the curtains. And don’t forget adding a pelmet cover above the heavy drapes – pelmets can double or even triple a window’s effective R-value. Adding blinds or curtains is the least effective method of heat control, but it’s also one of the least expensive options.

5. Make the Most of the Cool Summer Breezes.

In a modern house it’s often said it’s best to close up during the heat of the day. From late afternoon onwards, throw open the windows; overnight temperatures are lower outside than inside. However, in an older Queenslander with poor insulation, sealing and ventilation can work against you, trapping the hot air inside the house. It’s a good idea to invest in an indoor-outdoor temperature device so you know when outside has cooled down and you can open up for some fresh air.

6. Clean your Fly Screens

On the topic of airflow, when was the last time your fly screens were cleaned? It’s surprising how much dust & dirt gets trapped in that fine mesh. A simple scrub down can almost double the airflow through your house, so definitely make it part of your spring cleaning routine!

7. Service Your Air Conditioner

Sometimes it’s just too hot, and you’ll end up turning on the air conditioner. But before you do, stop for a moment and think – when was the last time you had yours serviced? Like any machine, it needs to be serviced regularly and its filters cleaned in order to get the most out of it! For tropical climates, most of the ‘heat’ you feel is caused by the high humidity, so setting your air Ccnditioner to dehumidify can also make your room feel much cooler.

8. Fans (ceiling & portable)

There are a few things you can do to make the air temperature inside your home feel lower through what we call natural or mechanical ventilation. This sounds a little technical, but it’s as simple as replacing a light fitting with a ceiling fan. This is cost-effective and provides a breeze when the air outside your home is uncomfortable or restricted because of poor ventilation. If you use a  ceiling fan or pedestal fans at the same time as your air conditioner, you can normally get away with setting your A/C a few degrees higher – and every degree higher you set, is another 10% to 15% less electricity it’ll use.
Just remember that fans only work when the room is occupied, as they’re designed to work on people, not on the building, or those savings might go to waste!

9. Make a “Cool Room”

It sounds pretty simple, but by closing doors and only cooling the room you’re using, you’re not wasting energy cooling the entire space. Using draft-stoppers on doors & sealing up window-leaks will stop that nice cool air from sneaking out. The room will also cool faster! Additionally, if you have notorious ‘hot rooms’, close the doors to these areas, to stop them heating up the rest of the house.

10. Extractor Fans

If you can’t stop the heat getting in, get it out! Exhausting the air through a roof ventilation fan can make a difference. There are many types of roof ventilators, and some are solar powered making them free to run. Be aware that “whirlybird” style ventilators provide only limited benefit because of their size and slow speed; a decent roof ventilator needs a fan inside it to provide maximum cooling potential.

11. External Upgrades

If living in an overheating (or oven-heating) home has become a constant struggle, it might be worth the effort to run the numbers on re-painting your home & roof to a lighter colour with additional heat protection.

These two things are the first line of defence in protecting your home against the scorching heat of the sun. They should be reflecting and releasing the sun’s energy rather than storing and absorbing it and pushing it into your home. That being said, these options can be expensive, so only consider this when they’re due for a replacement or upgrade already, or if the heat creates real problems in your household.

12. Invest in Insulation

Insulation can make a big difference, especially if you currently don’t have any. Adding additional insulation does normally help, but it has diminishing returns on making your home cool. When outside is hot (even at night) then the thermal resistance, or R-value of all building external surfaces controls the amount of unwanted heat entering your home.

How much insulation is enough? What type of insulation works best? There are a few rules of thumb you can use as guesstimates, but this really is something that needs to be calculated for your actual building. The calculation is an Energy Efficiency Assessment, which estimates the amount of overheating that needs to be removed to stay comfortable.

Keeping cool without losing your cool

Remember that some “solar treatments” designed to cool your home in summer may also make the home cooler in winter, resulting in more heating required. You’ll have to think about whether or not this will happen with the changes you’re making, and if this is a fair trade off. But keep in mind that it’s much easier to add another layer of clothing in winter than to take off another layer of clothing in summer.

The examples above show that modifications can be made to make hot homes more comfortable to live in. Heat does not always have to be reduced through active means like air-conditioning. Modifications to windows or home surrounds means that less heat will enter your home. When considering modifications, keep in mind the cost vs performance of different solutions. Preventative measures can save the environment & your money by making your home more energy efficient!

The post 12 Tips to Keep Cool & Save Energy this Summer appeared first on Anderson Energy Efficiency.

Some buildings are just harder to keep warm, especially if you have an older home with poor insulation and little or no weather sealing. Using some of these tips should not only help you save money, but also keep you warm & comfortable throughout the long chilly evenings.

Is your house as cold as an Igloo? Here’s some tips to change that!

1. Let the sun in!

   The sun is the best source of free heating you’ll find anywhere. Once the sun is up, open up the curtains to maximise that solar heat gain. It’s also a good idea to prune back over-hanging branches or large bushes that might obstruct sunlight coming in the windows.

2. Contain the heat!

   Once you’ve got all that free solar warmth, you’ll want to keep as much of it in your house as possible. So close those drapes before it starts getting dark. It sounds simple, but windows are a big influence on the inside temperature of your building – glass’s insulation R-value is around a hundredth an average wall’s insulation R-value. Well-sealed heavy drapes with pelmets, blinds & curtains can help ‘trap’ the heat inside your home. Try touching you window glass with your hands and feel how cold it is. Closing the curtains or adding a thick fabric lining can make a big difference to the warmth in your home.

3. Think about airflow!

   Heat only the room you’re in by closing any adjacent doors. If there’s an exhaust fan, this can replace cold air from outside. By exhausting the moist air from rooms such as bathrooms, kitchen or laundry, you can avoid condensation, dampness & mould. A stuffy room may not be too healthy. If you live in a really cold climate, consider investing in an energy recovery ventilator that can filter & preheat outside air with the warmer exhaust air.

4. Rugs

   Windows aren’t the only thing that can leak heat out of a room. Uninsulated floors (especially tiled & wooden surfaces) can account for up to 10% of a room’s heat loss. Putting down floor rugs & mats will help keep a room warmer while making it more pleasant to walk on barefoot. You can always roll them up & put them away when the weather warms up again.

5. Fire places need separate combustion air

   Fireplaces aren’t in every house, but for the few that have them, they need to be used carefully. Fireplaces with chimneys might seem warm & cosy, but they’re actually terribly inefficient for heating the rest of your home. If the fireplace does not have separate outside air combustion (with an air-tight front), cold outside air is pulled into the house in other rooms to make up for all the hot air being exhausted up through the chimney. This makes the room containing the fireplace warmer, but the rest of your house actually gets colder!

6. Mind the Gap

   Sealing any gaps is the best way to reduce unwanted air leakage. The best places to start are around doors and windows. For doors, you can buy door sweeps to seal the gaps underneath; or if you’re feeling crafty you can try making a “door snake” out of a long tube of fabric & filling it with rice.For gaps around the sides & top of a door, as well as window gaps, use weather stripping. It might seem like a trivial gap, but sealing up air leaks can definitely make a big difference, especially because these small gaps are multiplied by how many external doors & windows you have all around the house.

   While some gaps are easy to spot, don’t forget the less obvious areas – where pipes or cables go into walls, behind the washing machine, under kitchen cupboards, and even key holes. If the gaps are big & out of sight and you’re on a budget, sealing them can be done easily with things like scrunched up newspaper, plastic bags, or old socks. But for more visible areas, sticky draught-excluder products or tubes of caulking are available in most hardware shops, as are keyhole covers. Even some older power outlets can leak air – for these, “childproof” caps can be used in unused power outlets on external walls to seal them up.

7. Gauge the temperature with an Infra-Red Thermometer.

   Used properly, an infra-red thermometer is the perfect tool to help you identify temperature differences that could be a result of air leaks & poorly insulated areas around the house. You can buy these non-contact thermometers from electronics stores for under $50, or even less online.

   An Infra-red thermometer can also quickly inform you of any heating or cooling problems with your air conditioner. Locate the air intake & compare the temperature of the air entering your air conditioner Vs the temperature of the air exiting the vents (taking into account the temperature settings) and you’ll have a good idea whether or not your unit is heating or cooling properly.

8. Ceiling Fans / Reverse Cycle Air Conditioning

   Check your ceiling fans to see if they have a “winter” setting. This setting reverses the direction the fans spin, gently “pushing” warm air around and down. It’s not too useful on faster speeds, but ceiling fans can be very helpful if you have high or pitched ceilings. Reverse Cycle air-conditioning is one of the most energy efficient ways of heating your home. When purchasing a reverse cycle air conditioner, try to purchase the most energy efficient model you can (ones with more Stars). The higher cost of getting a more energy efficient model will definitely pay you back with lower power bills in the future. Additionally, the Reverse Cycle Air-conditioner will be able to cool your home in summer. To maintain them at their best performance, make sure your air conditioner is serviced regularly and that the filters are cleaned (most units recommend at least annually).

9. Insulate

   Your infra-red thermometer will certainly tell you that your ceiling can be a source of heat loss in winter and heat gain in summer. Ceiling insulation will mitigate the effects of your roof’s exposure to the harsh temperatures of the outside world. Adding insulation to cold walls (South-facing in the southern hemisphere) will reduce unwanted chills. If you have a suspended floor and find that it’s still too cold with rugs, consider adding underfloor insulation – but be aware this will make your home warmer in summer.

10. Ultimately, keep yourself warm vs the whole house

    The house doesn’t really care if it’s feels a little chilly, but you care if you’re cold. Everyone has their own unique comfort tolerance for temperature; one person’s ‘cool’ is another’s ‘freezing’. In all likelihood, you can probably handle the thermostat being a couple degrees lower than what you’re used to. But being comfortable is key. You don’t want to be so cold that you have to wear multiple jumpers in your own home. As a rough rule of thumb, if you need to wear a jumper outside, wear something warm inside too to reduce the cost of heating.

The post 10 Energy Saving Tips to Help Heat your Home appeared first on Anderson Energy Efficiency.

Energy Efficiency isn’t just in our name, it’s what we strive for. We’d like to show you that going “green” is not only an achievable goal, but in many cases it can also have a positive impact on your wallet!

A few years ago we installed a Photovoltaic (PV) Solar Panel system on our roof. It consists of 20 panels mounted on angled frames, with a peak capacity of 5kW. Solar panels also have the added benefit of shading your roof. And to show some hard numbers for the kind of benefits this system can provide, we’re releasing a copy of one of our own recent 12 month Electricity Consumption Reports, which includes Peak electricity, Hot Water (Tariff 31) and Renewable Energy generation (Solar PV).

The surplus electricity generated by the PV system means that our Mains meter reading was lower than average. In fact, over the last year we have actually generated more surplus electricity than we purchased! Because Tariff 31 is overnight (from 11pm to 7am), there was (of course) no solar contribution made during that time.
Here’s the technical breakdown:

Average export Net Solar = 10.9kWh/day
Compared to:
Average import Peak+Tariff 31 = 6.2kWh/day
Year-long average gross export = 4.7kWh/day

The average export during Winter was only 2.4kWh/day, but the average export in Summer was 6.7kWh/day.

Producing our own solar power wasn’t enough! We also made the business decision to purchase all our grid-supplied electricity as 100% Green Power (mostly wind-sourced). Talk to your supplier about making the switch to “Green” power. Therefore what grid power we do purchase is all 100% sustainable. Additionally, because we generate more renewable energy than we use, we export it back into the grid making us “Doubly Green” – we actually have negative Greenhouse Gas emissions!

The post Our Electricity Consumption creates Zero Emissions appeared first on Anderson Energy Efficiency.

Thermal mass is the ability of a building material to absorb and hold onto heat energy. A rough rule of thumb is that the heavier a material is, the more thermal mass it has. High density materials (such as concrete) have a high thermal mass, whereas lightweight materials (such as wood) have lower thermal mass.

We used DesignBuilder to model three different locations for the JV3 simulation: Darwin, Brisbane and Melbourne. These represent hot, warm/cool and cold climates. Buildings operated at other conditions will, of course, have different results. We modelled an office building measuring 30m × 15m × 3.5m with the longest-side facing North. We investigated the building envelope (roof, external walls and suspended floor), with varying solar absorptances, insulation and thermal mass. We also compared heat transfer (kWh) against the JV3 Reference Building – which is a basic structure that meets the DTS requirements of the Code.

You can see the annual total heat transfer (kWh) for different roofs in the graphs below. A positive number means that heat is transferring into the building, while a negative number means that heat is transferring out of the building. This heat transfer must be balanced by either artificial cooling, artificial heating or heat transfer in the opposite direction from other elements. We made all the graphs have identical scales to so you can easily make comparisons between locations.

Graphs of External Floor Colour vs Building Energy Consumption

Results

Solar Absorptance: You might not have expected this one – colour makes some difference to the heat transfer through a suspended floor! In all climates that we simulated (but not necessarily for every climate in Australia), darker colours perform better than lighter colours. This is likely due to the darker colours better absorbing the ground temperature, which in almost all situations is a good thing. Colour has a larger impact if the floor isn’t insulated. In the most extreme case in Darwin, changing from a light-coloured suspended timber floor to a dark-coloured suspended timber floor improved performance more than staying the same colour & adding R2.0 insulation.
Thermal Mass: If the floor isn’t insulated, you can see a significant variation between annual aggregate heat transfer of timber and concrete. Thermal mass obviously plays an important role in a building’s thermal performance. However if the floor is insulated, there’s little difference between timber or suspended concrete. Most of the beneficial thermal mass of a concrete floor is lost when it’s insulated.
Insulation: Increasing floor insulation was beneficial in all locations the simulated (but that doesn’t necessarily mean it’s true for every climate in Australia). Hot or warm climates require less insulation as this may aid the night-time cooling effect. Cold climates need some insulation to reduce heat transfer to the cold outside air and minimise their annual heat loss.

As always, the optimum performance of your specific building will depend on a combination of the most suitable solar absorptance, insulation and thermal mass of each element. Every building really is different!

Reference Building and Elemental Trading

In a Deemed-to-Satisfy report, elemental trading is not possible because every separate element needs to perform the same or better than the minimum Code requirements. However, to comply with a JV3 assessment, only the Annual Energy Consumption of the proposed building as a whole needs to be less than the Reference building. This lets you trade the benefits between elements – you can choose elements which perform better than the DTS minimum requirements in one area and use that to offset other elements that are less than DTS minimum requirements. For example, it’s possible to achieve a Building Solution by trading non-compliant DTS insulation for:

• Better than DTS-compliant glazing
• Better than DTS surface solar absorptance
• Better than DTS in available thermal mass

Despite having a non-DTS complying element, the proposed building can still comply with NCC Performance Requirement JP1 with a JV3 assessment if your Annual Energy Consumption is less than the Reference Building. This means a Verification Method assessment can offer substantial savings in construction costs. In our experience, we frequently find that a JV3 assessment can provide a more economical Building Solution for your project than a DTS assessment.

If you liked this article, be sure to check out Part 1 which covers roofs, and Part 2 which covers external walls. And don’t forget to Subscribe to our Newsletter to be notified of future articles like these!

The post Elemental Trading Part 3: External Floors appeared first on Anderson Energy Efficiency.

Thermal mass is the ability of a building material to absorb and hold onto heat energy. A rough rule of thumb is that the heavier a material is, the more thermal mass it has. High density materials (such as concrete) have a high thermal mass, whereas lightweight materials (such as wood) have lower thermal mass.

FC panel wall types are Fibre-Cement panel sheeting, also commonly known as plasterboard, drywall or Gyprock.

We used DesignBuilder to model three different locations for the JV3 simulation: Darwin, Brisbane and Melbourne. These represent hot, warm/cool and cold climates. Buildings operated at other conditions will, of course, have different results. We modelled an office building measuring 30m × 15m × 3.5m with the longest-side facing North. We investigated the building envelope (roof, external walls and suspended floor), with varying solar absorptances, insulation and thermal mass. We also compared heat transfer (kWh) against the JV3 Reference Building – which is a basic structure that meets the DTS requirements of the Code.

You can see the annual total heat transfer (kWh) for different roofs in the graphs below. A positive number means that heat is transferring into the building, while a negative number means that heat is transferring out of the building. This heat transfer must be balanced by either artificial cooling, artificial heating or heat transfer in the opposite direction from other elements. We made all the graphs have identical scales to so you can easily make comparisons between locations.

Graphs of External Wall Colour vs Building Energy Consumption

Results

There’s all sorts of interesting insights we can learn from these graphs.

Solar Absorptance: If a wall isn’t insulated, colour can vary the amount of heat transfer through the walls. In hotter climates it’s better to use a lighter colour while in cooler climates, a darker colour is better. Hopefully this isn’t a surprise to you! However the optimum colour for highest benefit depends on the building’s insulation, thermal mass and the climate.
Thermal Mass: If the wall isn’t insulated, there’s a significant variation between annual aggregate heat transfer of FC panel and concrete panel. This means that a wall’s Thermal mass plays an important role. However if the wall is insulated, there’s little difference between the material used. Therefore, most of the benefits of concrete panel’s high Thermal mass is lost when it’s insulated.
Insulation: Now for something that may be surprising to you – increasing wall insulation is not always beneficial in all locations! Yes really – there are times where you can have too much insulation! Hot or cold climates benefit from some insulation to reduce heat transfer, and warm or cool climates require less insulation

As always, the optimum performance of your specific building will depend on a combination of the most suitable solar absorptance, insulation and thermal mass of each element. Every building really is different!

Reference Building and Elemental Trading

In a Deemed-to-Satisfy report, elemental trading is not possible because every separate element needs to perform the same or better than the minimum Code requirements. However, to comply with a JV3 assessment, only the Annual Energy Consumption of the proposed building as a whole needs to be less than the Reference building. This lets you trade the benefits between elements – you can choose elements which perform better than the DTS minimum requirements in one area and use that to offset other elements that are less than DTS minimum requirements. For example, it’s possible to achieve a Building Solution by trading non-compliant DTS insulation for:

• Better than DTS-compliant glazing
• Better than DTS surface solar absorptance
• Better than DTS in available thermal mass

Despite having a non-DTS complying element, the proposed building can still comply with NCC Performance Requirement JP1 with a JV3 assessment if your Annual Energy Consumption is less than the Reference Building. This means a Verification Method assessment can offer substantial savings in construction costs. In our experience, we frequently find that a JV3 assessment can provide a more economical Building Solution for your project than a DTS assessment.

If you liked this article, be sure to check out Part 1 which covers roofs and Part 3 which covers external floors. And don’t forget to Subscribe to our Newsletter to be notified of future articles like these!

The post Elemental Trading, Part 2: External Walls appeared first on Anderson Energy Efficiency.

Thermal mass is the ability of a building material to absorb and hold onto heat energy. A rough rule of thumb is that the heavier a material is, the more thermal mass it has. High density materials (such as concrete) have a high thermal mass, whereas lightweight materials (such as wood) have lower thermal mass.

We used DesignBuilder to model three different locations for the JV3 simulation: Darwin, Brisbane and Melbourne. These represent hot, warm/cool and cold climates. Buildings operated at other conditions will, of course, have different results. We modelled an office building measuring 30m × 15m × 3.5m with the longest-side facing North. We investigated the building envelope (roof, external walls and suspended floor), with varying solar absorptances, insulation and thermal mass. We also compared heat transfer (kWh) against the JV3 Reference Building – which is a basic structure that meets the DTS requirements of the Code.

You can see the annual total heat transfer (kWh) for different roofs in the graphs below. A positive number means that heat is transferring into the building, while a negative number means that heat is transferring out of the building. This heat transfer must be balanced by either artificial cooling, artificial heating or heat transfer in the opposite direction from other elements. We made all the graphs have identical scales to so you can easily make comparisons between locations.

Graphs of Roof Colour vs Building Energy Consumption

Results

There’s all sorts of interesting insights we can learn from these graphs.

Solar Absorptance: As you’d expect, the solar absorptance used in the building makes a huge difference. Darker colours result in hotter buildings, while lighter colours result in cooler buildings. Using certain colours in certain climates will reduce your building’s thermal performance. The optimum colour for the highest benefit depends on the building’s insulation, thermal mass and climate. As Brisbane is a mild climate, you can still use most colours providing you use insulation. In Melbourne you can get away with less insulation when you have a darker roof colour to minimise the need for heating, and in Darwin a lighter roof colour helps minimise the need for cooling.
Thermal Mass: If the roof is not insulated, there’s a significant variation between the annual total heat transfer between metal and concrete. This shows that thermal mass can play an important role in thermal performance in some scenarios. However if the roof is insulated, there’s little difference between the two materials. Thus, most of the beneficial thermal mass of a concrete roof is lost when it’s insulated.
Insulation: Adding roof insulation reduces the heat transfer through the roof (which hopefully shouldn’t come as a surprise to you). However, what may be surprising is that increasing roof insulation is not always beneficial! For example, In Darwin, using no insulation and a light colour helps with the night-time cooling effect to lower the building’s total Energy Consumption. Likewise, in Melbourne, using no insulation and a very dark colour may in some scenarios reduce the annual heat loss.

As always, the optimum performance of your specific building will depend on a combination of the most suitable solar absorptance, insulation and thermal mass of each element. Every building really is different!

Reference Building and Elemental Trading

In a Deemed-to-Satisfy report, elemental trading is not possible because every separate element needs to perform the same or better than the minimum Code requirements. However, to comply with a JV3 assessment, only the Annual Energy Consumption of the proposed building as a whole needs to be less than the Reference building. This lets you trade the benefits between elements – you can choose elements which perform better than the DTS minimum requirements in one area and use that to offset other elements that are less than DTS minimum requirements. For example, it’s possible to achieve a Building Solution by trading non-compliant DTS insulation for:

• Better than DTS-compliant glazing
• Better than DTS surface solar absorptance
• Better than DTS in available thermal mass

Despite having a non-DTS complying element, the proposed building can still comply with NCC Performance Requirement JP1 with a JV3 assessment if your Annual Energy Consumption is less than the Reference Building. This means a Verification Method assessment can offer substantial savings in construction costs. In our experience, we frequently find that a JV3 assessment can provide a more economical Building Solution for your project than a DTS assessment.

If you liked this article, be sure to check out Part 2 which covers external walls, and Part 3 which covers external floors. And don’t forget to Subscribe to our Newsletter to be notified of future articles like these!

The post Elemental Trading, Part 1: Roofs appeared first on Anderson Energy Efficiency.

• Increase the insulation?
• Increase the efficiency of the compressor motor fans & lights?
• Or reduce the amount of infiltration (air leakage)?

Dr Clyde Anderson and Certified Energy Efficiency Assessor Michael Anderson have written an in-depth report comparing the energy consumption between existing and proposed-design walk-in Coldrooms with various options applied.

Read the full report on Walk-In Coldroom energy efficiency now

It’s a great read, but if you’re short on time here’s a quick summary:

1. There is a proposal from the Equipment Energy Efficiency Committee (E3) of the Australian and New Zealand Ministerial Council on Energy to regulate elemental parts of Walk-In Coldroom systems.
2. Rudimentary thermal modelling was included in the proposed 10 year strategic Draft proposal “In From the Cold… ”.
3. Manufacturers of insulation products — through the industry governing body “Expanded Polystyrene Panel Manufacturers Group” — are planning to make a submission to the Committee regarding the benefits of the proposed insulation increases.
4. Our Report addresses only the proposed changes in minimum R-value insulation of wall, ceiling and floor panels. It shows that increasing insulation R-value will only slightly reduce the energy consumed in Walk-In Coldrooms.
5. There are many transient heat loads that are part of operation of WICs that are difficult to include any energy efficiency regulation.
6. Compared to steady-state (closed box) heat transfer, one important factor in the calculation of total kWh energy is the loss of cold air due to door opening (infiltration).
7. Increasing only insulation will not achieve the expected overall benefits as the envelope heat transfer is only a small percentage of the total heat load.
8. Infiltration should be addressed before increasing the R-values of Walk-In Coldroom envelopes, as this would give a more cost-effective energy reduction.
9. A holistic, total system approach to efficiency certification of WICs is advocated since the incorrect application of efficient components can result in an inefficient design.
10. Performance-based assessment under a National regulatory body like the Australian Building Codes Board, is appropriate for WICs.

Disclaimer: whilst the data in this Report is provided with reference to calculations and computer simulations, it is only as good as the information provided plus the assumptions used in the simulations and is generic in its recommendations. Naturally, this may not reflect your specific building or simulation scenario. Alternative data & assumptions, different building designs & building fabric will produce different simulation results. If you’re interested in optimisation for your specific building, we offer full Commercial Energy Efficiency Assessments as well as thermal simulation consulting. Contact us for more information.

Read the full report on Walk-In Coldroom energy efficiency now

The post Refrigerated Walk-In Coldroom Comparisons Report appeared first on Anderson Energy Efficiency.

Riding it is like riding a Segway, but with only one wheel – you move and steer by gently leaning in the direction you want to travel. It’s been assembled from off-the-shelf components as well as some custom-made parts. The 600 watt motor is fully reversible so there’s no front or back. It also features full regenerative braking, so whenever you slow down it recharges the batteries too. Its range is around 10-12km depending on terrain with a maximum speed of 18km/h, so it won’t take you down the highway, but it will take you from your front door to the bus stop with ease. The larger wheel size compared to small scooter wheels gives much better handling in rougher terrain.

Our Electric Car (which is one of the more efficient EVs on the road) averages an overall efficiency of 205 watt-hours per kilometre in everyday use, mainly because it weighs almost a tonne which means it has a much greater mass to move around. Electric bicycles are much lighter & better; they tend to average around 30 watt-hours per kilometre. Meanwhile, this unicycle weighs under 10kg so it averages under ten watt-hours per kilometre in everyday use – that’s over twenty times as efficient and kinder to the environment, with far less embodied energy costs too!

Thanks to its incredibly low embodied energy and light weight, this prototype also worked out far cheaper than we anticipated – the total build cost was under $400. If you’d like to know more about either of our electric vehicles, or anything else related to energy efficiency, don’t hesitate to contact us. We’re serious when we say we don’t just talk the talk, we walk the walk… Or in this case, ride the ride!

The post Our Self-balancing Electric Unicycle appeared first on Anderson Energy Efficiency.