The Architect’s Air Conditioning Guide
Understanding the Components That Go Into a Home HVAC System
In Texas, a solid air conditioning plan is one of the most important components of designing a home. However, many families building their first home don’t know the air conditioning and heating options available to them, components of an HVAC system, or design choices that can affect interior aesthetics. Our Austin-based architects have put together a complete air conditioning guide, including the considerations to make when building your home, different heating and cooling systems available, and choices to keep in mind for the home interior. Make sure to consult this air conditioning guide to stay cool and comfortable year-round!
Preparing Your Home: Choosing the Right Insulation
Before selecting an air conditioning system, it is necessary to ensure your home is properly insulated. Insulation functions to decrease the amount of heat entering the house when it’s hot and increase the amount of heat retained when it’s cold. It works hand in hand with your HVAC system to promote efficiency and regulate your interior temperature more cost-effectively. Insulation is rated by its R-value, which measures heat resistance and ability to control climate. R-value relates to the effectiveness of the insulation – the higher the number, the better the product. Different regions often require different R-values. In Austin, Texas, the city code requires insulation with an R-19 value in the walls and an R-25 value in the ceiling.
Blown-in Insulation
Blown-in or loose-fill insulation is sprayed into place. It is best for attics, hard-to-reach spaces, and new construction homes. It has a higher R-value, excellent for insulating homes in hot climates like Texas. Blown-in insulation is typically more efficient than traditional batt insulation.
Batt Insulation
Batt insulation is panels of pre-cut insulation resembling a thick blanket. Due to the pre-cut sections, batt insulation is subject to leaving gaps which can reduce efficiency. This type of insulation fits best between the studs of framed walls but can be challenging to apply in oddly shaped areas. Batt insulation tends to offer less climate control and efficiency than the blown-in option.
What is a SEER Rating?
SEER stands for Seasonal Energy Efficiency Rating, and it measures the efficiency of the air conditioning system. It is calculated by dividing the cooling output by the total electric energy input during the peak cooling season. Most air conditioners have a SEER range from 13 to 21 and must meet a ranking of 14.5 to qualify for an Energy Star rating. Typically, the higher the SEER, the higher the efficiency of the air conditioner. Factors that affect SEER include the size of the home and the region where it’s located.
Ducted vs. Ductless Air Conditioning Systems
When designing a home air conditioning system, there are two main choices available: ducted and ductless. Ducted systems rely on ductwork that runs through the walls and ceilings of the home to distribute air to each room. Ducted systems are often standard in new construction but may pose a challenge for older homes built before central air was common. Ductless systems don’t rely on ductwork but instead, feature indoor units for each room that can be operated independently and easily installed in older homes.
Central Air Conditioning
Central air conditioning is a ducted cooling system that includes an external condenser to cool air and an air handling fan to blow it through the ductwork and deliver chilled air throughout the house.
Mini-split Systems
Mini-split systems are a popular ductless air conditioning option. These systems feature units strategically placed throughout the home to cool the assigned area. Mini-splits come in a range of styles, and they can be installed on the wall or flush to the ceiling. It is a popular system to use in older home renovations. Mini-split systems also offer increased efficiency because you can choose the rooms you want to cool.
Electric vs. Gas Heating Systems
While a top-notch A/C system is a top priority for hot Texas summers, homeowners also need to consider heating options for the short winter months here in Austin. Two popular choices for heating include electric heat pumps and gas furnaces.
Heat Pump
Electric heat pumps function similarly to a central air conditioning system but in reverse. While air conditioners move heat out of the home, heat pumps bring heat into the house. Heat pumps are very energy efficient and don’t take up a lot of square footage. They work better in mild southern climates where the temperatures don’t drop below freezing.
Furnace
While a gas furnace is more expensive to operate and takes up more space than a heat pump, it is necessary for extreme climates with freezing temperatures. A furnace uses natural gas to heat air distributed through the home, drawing in the denser cold air to be reheated.
Return Air vs. Supply Air
Central HVAC systems rely on a continuous cycle of cooling or heating by running air back through ducts and vents located in the home. There are two main vents in your home HVAC system: return air and supply air. These vents are often confused, but each serves a very different purpose.
Return Air Vents
Return air vents suck or return air back to the HVAC system to be cooled or heated again. The return air grille will often be the larger vent. When designing homes, architects aim to hide this vent as much as possible while still maintaining good airflow.
Supply Air Vents
Supply air vents blow or supply air to each room. These are the smaller vents typically located close to the ceiling.
HVAC System Aesthetics to Consider
While the residential architects will be responsible for designing the HVAC system and choosing the placement of air vents or mini-splits, the homeowners will have to make some choices that will affect the interior aesthetics of the home. Consider the following options.
Traditional Grilles
Traditional HVAC grilles typically feature white rectangular covers with a series of adjustable vertical and horizontal vents. More decorative options are available in metallic finishes and ornate designs.
Slot Diffusers
Slot diffusers have a more linear and narrow profile than traditional grilles. They can give a room a more modern feel, be easier to conceal, and provide improved airflow.
Exposed Ductwork
Typically, ductwork is hidden inside the ceiling and walls. However, many homeowners are opting for exposed ductwork to achieve higher ceiling heights and an industrial feel. It is important to note that exposed ductwork is actually more expensive and requires finishing details that concealed ducts do not.