Put simply, a net zero energy home is a home that is so energy efficient that it can afford to return energy back to the grid. It is not a home that uses no energy, but one that can actually produce more than it needs.
This can be done by either using methods that take advantage of the available sources of energy, installing devices that allow you to harvest renewable resources, or building with energy conservation in mind. But in order to reach net zero, all of these will need to be used together in most cases. Here are the steps needed to build the perfect net zero energy home.
Sealing and Insulation
Everything should start with a properly insulated and air tight home. As a matter of fact, many technologies will not work efficiently unless airtightness requirements are reached, such as heat recovery ventilation systems, for instance.
These systems allow you to use the heat that is generated by heating in the winter to heat air that is coming in, and cold air generated by AC in the summer to cool hot air from outside. It does this by circulating the air through a heat exchanger that mixes the air that is being expelled out with the air being brought in. These systems can allow you to not only save energy on conditioning, but could also help greatly improve the air quality inside your house.
Insulation and sealing are also important to keep moisture out, which requires more energy to heat. The floors, ceilings, and walls have to be properly insulated. Special attention also has to be given to vulnerable areas like around the doors and windows. The builder should pick the proper door and window sizes to minimize loss and maximize passive energy gains.
Once this is all done, a “blower door” test will have to be performed to assess the airtightness of the home. The ACH rate, which stands for air change rate per hour, will have to be below 1 for maximum efficiency.
Solar energy will handle a large portion of your energy needs, and you have to find a good contractor who can offer a variety of solar panels and battery storage solutions. Companies like Semper Solaris can handle everything from roofing, heating and air conditioning, as well as solar panel installation and solar repair. Working with them will allow you to save on separate services and avoid confusion with multiple contractors who may have conflicting ideas.
It’s always a better option to work with people who can work on different areas and be able to provide input on the building process. For instance, the way the home and windows are oriented will play an important role. In the winter, the south side of the house should have enough windows to harness the power of the sunlight to reduce heating costs and demand on your system. In the summer, covering the same windows with roof eaves or other shading techniques will be essential.
Depending on where you live, much of your energy consumption will come from your HVAC system. This is why it will be important that you invest in money saving super-efficient solutions if you want to be able to reach net zero. Systems with ductless heat pumps are considered some of the most economical on the planet, and are a great choice for anyone who wants to reduce their consumption while still getting a very efficient system. These are much cheaper than your average geothermal heat pump systems, and also are much cheaper to operate while carrying none of the burden of forced or central air systems.
In addition to that, waste water and air heat recovery technology can help you recuperate some of the energy from these sources.
Conservative Water Heating Technology
Hot water is also one of the major energy expenses in any house, and you’ll have to choose an option that is as conservative as possible. You also have to take your home’s household needs into consideration.
For instance, while many tankless water heaters might be some of the most energy efficient options on the market, they might not work for you. The way these systems work is that they create hot water on demand by using heating elements that heat cold water as it is pumped out. These units do have their benefits, but they have their cons as well.
If your household has heavy needs for example, these systems may not be able to supply multiple users at once. You won’t be able to use hot water for both the shower and dishwasher at the same time, for instance, unless you buy multiple units, which will cost you a lot of money.
In these cases, a hybrid heat pump electric water heater might be your best bet. These units have the lowest operating cost out of all tank models and combine the best of both tankless and traditional water heaters.
How they work is that they use the power of ambient air to heat water that is contained in a tank. This is why this is one of the best options if you live in a hot area. You can maximize these effects by installing the unit in a particularly hot part of the house, like a hot garage or attic. These units also have conventional coils that will be activated in case the air alone is not enough to supply you with hot water.
However, there are some things that need to be considered before you go with these units. For one, they will need some space to operate properly. Most will need around 1000 ft³ of free space to work efficiently. They also cost a bit more than traditional units. However, you might be eligible for tax cuts and rebates in certain states, so make sure you look into it wherever you are.
High Efficiency Appliances
Now that the hot water situation is figured out, you’ll have to pick the right appliances as well. Home appliances will usually make up about 60 percent of the total consumption in your average net zero home, so this is an area that will necessitate a lot of attention.
You should go for appliances that not only have great Energy Star ratings, but also are immune to phantom energy losses. Phantom energy losses are when a particular appliance continues to consume energy when plugged in, even when not in function. These “energy vampires” as they’re also called, could account for as much as 15 percent of a house’s total energy consumption. So that’s something every home should try to avoid at all costs.
But if you really want to make sure that you reach your objective, you’ll also need an energy dashboard that will allow you to keep track of your consumption. It will also allow you to gauge how much energy your home is generating. You’ll then be able to make the proper adjustments to make sure that you input and output is properly balanced
Achieving net zero is something that has to be planned from the very beginning. This is why it’s important that you choose the people you work with properly, and also educate yourself in order to avoid potential mistakes and be able to provide insight as well.