How Building Orientation Affects the Outcome of a Manual J Load Calculation
How Does Your Building’s Orientation Impact its Ability to Keep You Warm or Cool?
Building orientation sounds like something that only an architect would care about, but that is far from being the case. In fact, it plays a critical role in determining how much energy your home needs to keep you comfortable.
After building orientation is explained further down below, you will realize how simple it really is. But for now, let’s keep it as basic as possible.
Building orientation is just a fancy way of saying which direction your house faces. But this affects everything! How much light and sunlight enters into your home. It determines how much heat it gains. Or loses, and even how hard the wind blows against it.
Does orientation matter? Of course! By understanding and optimizing your home’s orientation, you can make sure it’s more comfortable to live in and costs less to maintain!
What Is Manual J Load Calculation?
We talked about one thing that could determine whether or not you should live in a certain house (orientation) so now we’ll give you another factor — load calculation?
Don’t worry! By the end of this article, you will have a clear understanding of what we’re talking about:
Load Calculation
Load Calculation is just a fancy way of figuring out how strong your heating or cooling system should be so that you’re not paying for excess power… or freezing because there isn’t enough!
It takes into account many different factors (including building orientation!) and can figure out exactly what kind of HVAC system you need by assessing things such as the size of your home, how well-insulated it is and even how many people live there!
Manual J
This is the full name: Manual J: Residential Load Calculation. It was created by Air Conditioning Contractors of America (ACCA). And here’s all you really need to know:
It is an ANSI-recognized national standard used for sizing residential HVAC systems.
When someone talks about “load calculation”, this is probably what they are referring to.
While there are alternative methods to the same result, Manual J has been used in practice for the longest time and is the most efficient way to get your desired results!
Why Do We Use Manual J?
Imagine if you could determine how many calories you burn throughout the day. Or even how much water your body needs to drink so that it performs at its peak.
It’d be a no-brainer, right? Well, we do have those calculations! And just like them, this one helps save you money and keep you comfortable!
By considering things such as how well your home is insulated, which direction it faces (building orientation), and also how many people live there… The manual j load calculation will figure out exactly what HVAC system you need.
According to ACCA — the creators of this calculation — improper HVAC installation can increase energy bills by 30% or more.
So if this applies to you, it’s worth looking into!
Whether you’re an architect or engineer needing paperwork done fast… or a homeowner who just wants to get their HVAC system up and running ASAP: Manual J has you covered. The service prides itself on providing fast documentation so that construction isn’t delayed.
Sustainable
Without any surprises during construction (like HVAC systems that are too large or small)… builders waste less materials making adjustments. Which means fewer trips to the store and less fossil fuel used to make them!
Builders who want to collect green building certification points have to submit accurate load calculations anyway. So why not do it from the start? That way there’s no last-minute work before submitting documents!
The amount of heating your building needs will be directly affected by the way it’s oriented. How it’s oriented will determine how much direct heat you’ll get throughout the day. When the sun shines on your building, the windows that face it will let heat in. This is great to warm a cold room up, but too much can cause overheating during certain times of day. So this could end up being a good thing or bad thing depending on the time.
The building envelope and heating load
Different ways a building can be oriented affects how much heat gets lost or gained through walls, roofs and windows.
Walls and windows that face south take in more sun than those that face north. As a result, they contribute more to heat gain and loss depending on what season it is.
Building orientation for passive heating
When we want our building to be heated passively we have to orient our buildings in a way that captures sunlight when we want it and blocks it when we don’t.
For example, positioning winter sunlight so it hits your walls and windows, but making sure summer hits them outside your space. Or using materials like concrete floors or walls to capture heat from the sun during the day and release it at night when temps drop low outdoors. By doing so you reduce how much power heating uses and save energy.
So next time someone starts talking about jargon things like “building orientation” just know they’re talking about how your building interacts with its environment. And if you understand that then you’ll understand how to save energy while keeping yourself comfortable.
Impact of building orientation on cooling load
We want our buildings to stay cool during hot months right? Well how well they do this relies heavily on their orientation relative to the sun. We want as little direct sunlight as possible to hit our buildings so they don’t warm up too fast.
Solar heat gain and shading
One thing that affects a buildings cooling load is solar heat gain. You’ll need to have your building oriented in a way that lets the least amount of sun hit it. For example, a building with a large south-facing wall will heat up like an oven because of how intense sunlight is. But one with a north-facing wall barely gets any sun.
In cases like this it’s important to use shading so you can combat excessive solar heat gain. Blocking the sun with things like awnings, trees or strategically placed louvers will help prevent your building from becoming too hot.
Where you put a window has consequences other than just letting light in and heating your building.
They can actually bring unwanted warmth into your building. By placing windows away from direct sunlight or utilizing special glazing, you can avoid unwanted heat.
There’s no secret that larger windows give a better view, but they also give more heat which requires the need for more light and air conditioning. It’s simple, larger windows means more and more. If you’re looking to keep things cool with a smaller cooling load try using smaller windows or shading devices.
Different types of windows exist too. Some areas require multiple paths for air so they might use two panes of glass rather than one. Others might design windows to catch the wind as it moves throughout the day and channel it through their buildings keeping them cool naturally.
Optimizing building orientation for energy efficiency.
Now that we know how building orientation affects cooling load, let's dive into strategies for making your workplace more energy efficient. You can actually decrease your company’s carbon footprint and limit energy consumption by optimizing your building’s orientation and incorporating passive design techniques.
Tips for optimal building orientation
When you’re deciding on a layout, take into account your location's climate. If you’re in a warm area, think about getting shade and reducing how much direct sunlight reaches through the longest walls of your building by facing them east-west. On the other hand, in cold areas make sure there is plenty of south-facing windows because it’ll help heat up the workplace during winter months.
Why passive designs are important
Firewalls, proper air ventilation, and having thermal mass work well with a good orientation. Using these three things can greatly improve the effectiveness of any type of building orientation. For insulation, focus on using it on walls floors and ceilings to keep heat transfers low. It might be obvious to have airflow but not everyone thinks about how it keeps temperatures stable indoors; imagine that! Finally, materials with high thermal mass such as concrete or brick are able to slowly absorb and release heat throughout the day keeping temperature just right 24/7.
Questions:
How does the way a building is pointed impact its heating and cooling bills?
The direction it’s pointed determines how much sunlight and wind it gets hit by. By optimizing this, buildings can be heated more by the sun in colder climates, or less in warmer ones. Similarly, coolers have to work less hard to cool buildings if they’re not getting cooked by the sun in the first place.
Is there such thing as an energy efficient building direction?
For sure. Buildings can be oriented in such a way that they get maximum natural light, heat from the sun, and ventilation from wind. This makes it so heaters, coolers, and lights don’t have to be used as much. It adds up to big energy savings.
How do I know which way my building should point?
It depends on your location. An architect or energy consultant can figure out what local weather patterns are like and tell you what is best for your area. Obstructions around your site also matter too. Once all of these factors are considered though, knowing where the sun will go throughout the day is important too.
Are there any examples of this working well in real life?
Yes! In fact there’s tons of them. A building facing north instead of west in hot climates could avoid getting overheated while still making use of natural ventilation. In cold places commercial buildings can get designed to maximize solar exposure and reduce heating costs at the same time.