Chicago is one of 14 US cities that is actively tackling climate change issues and doing what they can to make the City as sustainable as possible. Chicago also boasts the largest, longest running greenhouse gas (GHG) emissions reduction program. Additionally, the City is more than 40 percent of its way to meeting its Paris Climate Agreement Goal. But how much can steps to reduce energy consumption, like using a split air conditioning system, help in the road to zero energy ready homes in Chicago?
The concept of Zero Energy Ready Homes was established by the US Department of Energy (DOE) in an endeavor to encourage builders and homeowners to construct and retrofit houses and other buildings to ensure not only outstandingly high levels of energy savings but also health, comfort, and durability as well.
Essentially, the DOE Zero Energy Ready Home has increased energy efficiency and improved air quality. It depends heavily on ENERGY STAR’s comprehensive building science requirements as well as best practices and proven innovations sourced by the DOE’s Building America Program.
Zero Energy Ready Homes have to fulfill certain very specific requirements. For instance, they must:
- Comply with at least four of ENERGY STAR’s Homes Program Requirements and Inspection Checklist.
- Thermal closure
- HVAC quality installation
- Water management
- Target home/size adjustment factor
- Incorporate ENERGY STAR appliances and fixtures to ensure these are energy efficient. This will obviously apply to split systems.
- Make use of high-performance windows that meet specific ENERGY STAR specifications, depending on the relevant climate zone. Chicago has a mixed climate with cold winters and warm summers and moderate temperatures during spring and fall.
- Comply with insulation levels set by the 2012 International Energy Conservation Code.
- Install ducts in optimized locations or conditioned spaces using the latest research recommendations.
- Conserve energy and water by using efficient hot water distribution systems that provide rapid hot water to homeowners.
- Make sure that indoor air quality complies with the Environmental Protection Agency (EPA) Indoor airPlus Program.
- Follow the PV-Ready checklist for places where the climate has significant solar insolation (or solar radiation in the form of sunlight). This will help to ensure savings on future costs of PV (photovoltaic) installations. These convert light into electricity, usually to heat water, however, the solar hot water provisions of the PV-Ready checklist are not mandatory any longer but are, nevertheless, encouraged.
Newly built DOE Zero Energy Ready Homes are 40 to 50 percent more energy efficient than conventional or traditional new homes. Requirements for houses built in the past three years (from 8th November 2015) have different options. To meet the requirements of a Zero Energy Ready Home it is essential to incorporate all the prerequisites and not just a selection.
Additionally, industry trends that are currently providing solutions for maximum efficiency in buildings include utilizing the most efficient systems and components. It is generally agreed by those in the industry that:
- Green buildings should be enabled
- There must be effective whole-building targets
- It is essential to focus on ventilation and air quality
- Buildings should be monitored
- Building subsystems must be coordinated
Since heating, ventilation, air conditioning, and refrigeration (HVACR) uses half of all the energy generated in US residential and commercial buildings, urgent action is being taken to phase down Hydrofluorocarbons (HFCs) that are produced synthetically, primarily for use as refrigerants. The DOE believes that this action can avoid up to 0.5 percent of global warming by 2100.
This, in itself, indicates that more energy efficient heating and cooling, including effective split systems, are vital.
Basics of Split Systems
Split systems incorporate air-conditioning or heat pumps that utilize refrigerant as the heat exchange fluid. Separate components incorporated in the design include a compressor, an evaporator, and a condenser.
Most central air-conditioning (AC) systems used in residential dwellings are split systems with the compressor and condenser located outdoors in a single unit. The evaporator, ductwork and refrigerant lines are located inside the building. But unlike heat pumps, AC units only cool spaces. Heat pumps, on the other hand, can also heat interiors.
Split systems are a lot quieter than conventional AC units largely because the noisy compressor and fan that cools the condenser are located outside. Traditional window units incorporate all parts of the system in one unit that is located inside.
Another big difference between the two options is that split systems, while they are cost-effective and efficient, are considerably more expensive than conventional systems and they must be professionally installed. Like solar heating, it is agreed that split systems will ultimately save not only energy but money as well.
More recent split systems optimize the matching of heating and cooling units. This includes exploiting the potential for operating heat pump cycles at the same time as using supplemental gas heating.
Small and flexible, mini split air conditioners are ductless and so avoid the typical energy loss associated with central forced air systems that require ducts to operate. They are also safer because they are installed without requiring unit-sized holes in windows or through walls. This also ensures that there isn’t a gap in the building envelope that will inevitably increase cooling loads.
There are numerous types including models with up to four units each of which handles a different room or zone. The benefit of these is that you can heat or cool one or more areas, depending on your unique needs at any particular time.
Ductless mini split heat pumps are regarded as a particularly good choice for retrofit add-ons to buildings that have heating systems without ducts including radiant panels, hydronic (water) heating, and space heaters that burn propane, kerosene, or wood. Like mini split AC units, they are small and flexible, energy efficient, and safer than conventional units.
Other common advantages include the fact that they can be configured and mounted on walls, floors, within ceilings, or in the form of a compact cassette.
The Best Split Systems for Chicago Buildings
Whether you are building a new home in Chicago or retrofitting an old one, the City’s renewable and energy efficient strategies can help ensure your living environment is more sustainable – and our team of MEP engineers is available to guide you.