AE 225 - ENIVRONMENTAL BUILDING SYSTEMS STUDIO
The Oasis @ PHX is conceived as a climate-responsive community library shaped by the realities of Phoenix’s hot–dry desert environment, where solar heat gain is the dominant driver of building performance. The design prioritizes passive control strategies first, using orientation, a fully glazed north façade, deep 2-meter overhangs, and a high-performance insulated envelope to reduce unwanted heat gain while maximizing controlled daylight. Recognizing that cooling demand far exceeds heating demand in this climate, the building integrates a hybrid mechanical system that pairs indirect evaporative cooling with a high-efficiency heat pump to maintain stable indoor temperatures and controlled humidity levels suitable for both occupant comfort and book preservation. The project demonstrates an integrated architectural and mechanical response, where envelope design, solar strategy, and HVAC performance operate as a unified system rather than independent components.
The primary façade establishes a transparent civic presence through expansive glazing and angled structural members that provide both visual rhythm and passive shading. The entrance sequence emphasizes openness and community engagement, allowing interior activity to remain visible while responding to the harsh desert climate through deep roof overhangs and high-performance envelope strategies.
The rear elevation highlights the building’s structural framework and integrated solar roof system. A repeating perimeter structure supports shading and enclosure while reinforcing the project’s climate-driven design language. Photovoltaic panels align with optimal solar exposure, transforming the roof into an active energy-generating surface.
An open, flexible learning environment designed to support early education, play, and informal gathering. Low shelving, soft seating, and natural daylight create a welcoming atmosphere while maintaining visual connectivity to the larger library space.
The central reading zone balances quiet study with social interaction through varied seating arrangements and clear circulation paths. Large glazing maximizes daylight while maintaining thermal comfort through the building’s climate-responsive envelope design.
Enclosed meeting spaces provide areas for focused work, tutoring, and digital collaboration. Integrated technology and acoustic separation allow users to engage in group discussions without disrupting the open library environment.
Phoenix’s hot–dry desert climate fundamentally governed the design direction of The Oasis @ PHX. With summer design temperatures reaching approximately 46°C and solar radiation levels among the highest in North America, cooling demand becomes the dominant performance driver. Winter conditions are comparatively mild, with design lows near 1–2°C, resulting in significantly lower heating requirements. This imbalance shifts the building strategy toward minimizing peak summer heat gain rather than optimizing for cold-weather performance.
High horizontal solar radiation throughout the year, combined with low relative humidity (often 10–20%), creates both a challenge and an opportunity. Solar exposure dramatically increases envelope and glazing heat gain, particularly on south and west façades during afternoon hours. In response, the building employs deep 2-meter overhangs, a fully glazed north façade, and controlled east and west glazing ratios to reduce unwanted solar loads while preserving daylight quality.
The large dry-bulb to wet-bulb temperature separation in Phoenix makes indirect evaporative cooling highly effective. This climatic condition directly informed the selection of a hybrid cooling strategy that leverages evaporative pre-cooling before secondary mechanical conditioning. Rather than relying solely on conventional air conditioning, the design uses climate-responsive logic to reduce mechanical lift, electrical demand, and peak system stress.
Peak Load Interpretation: The summer design case indicates a total heat gain of approximately 47 kW, with solar heat gain accounting for nearly 46% of total load. This confirms that shading and glazing control are more impactful than envelope conduction alone. By reducing solar gain through passive strategies, the building lowers required mechanical capacity and improves long-term system efficiency.
The comparison between cooling demand and photovoltaic output demonstrates strong alignment between peak energy production and peak cooling load. During mid-day hours, when solar radiation is at its maximum, photovoltaic panels generate their highest output, coinciding with the building’s highest cooling demand. This synchronicity strengthens the feasibility of integrating rooftop solar panels as a strategy to offset operational electricity consumption.
By sloping the roof toward the south and optimizing panel orientation, the building transforms its largest environmental challenge, intense solar exposure, into an energy asset. Rather than treating solar radiation purely as a heat gain problem, the design leverages it to support long-term operational efficiency and reduce grid dependency.
The mechanical design for The Oasis @ PHX employs a hybrid cooling strategy tailored to Phoenix’s hot–dry climate. An indirect evaporative cooler (IEC) provides primary cooling by leveraging low ambient humidity to efficiently reduce air temperature without adding moisture that could compromise book preservation or indoor material stability. A variable-speed heat pump supplies trim cooling and mild winter heating, maintaining indoor temperatures within a stable 22–24°C comfort range. An integrated energy recovery ventilation approach balances outdoor air requirements while minimizing unnecessary thermal loss or gain. By staging the cooling process, the system reduces peak electrical demand, improves part-load efficiency, and maintains controlled humidity levels appropriate for both occupant comfort and long-term durability of interior materials.
The CW-3 Climate Wizard indirect evaporative cooler serves as the primary cooling stage for the building. Located on the west façade within the mechanical zone, the unit precools incoming outdoor air using a heat exchanger that removes sensible heat without adding moisture. This approach is well-suited to Phoenix’s hot–dry climate, where low ambient humidity allows significant temperature reduction through indirect evaporation while maintaining stable indoor relative humidity for occupant comfort and book preservation.
The mechanical system is organized around a central supply trunk that distributes conditioned air evenly across the open-plan library. The Mitsubishi air handling unit works in series with the indirect evaporative cooler to provide trim cooling and heating as required. Short lateral branches minimize pressure drop and improve airflow balance, while strategically placed diffusers deliver conditioned air to reading zones and perimeter glazing areas. Return air is routed back through centralized ducting to maintain circulation efficiency and consistent indoor thermal conditions.
P3_Team15_Phoenix (1).pdfThis technical report documents the preliminary thermal and mechanical analysis undertaken to evaluate building performance in Phoenix’s hot–dry climate. The study quantifies seasonal heat transfer through the envelope, internal load contributions, solar gain impacts, and ventilation losses to establish peak heating and cooling demands. Multiple HVAC system configurations were assessed based on energy efficiency, climate suitability, and operational feasibility, leading to the selection of a hybrid indirect evaporative cooling and heat pump system. The report synthesizes climate data, load calculations, and system comparisons to support an integrated, performance-driven design approach.
A fully glazed curtain wall maximizes daylight and visual openness, while the deep roof overhang reduces peak solar heat gain. Exposed timber columns express structural rhythm and support the extended roof plane.
An opaque south façade minimizes direct solar gain and consolidates mechanical equipment within a defined service zone. The perimeter timber structure continues to reinforce shading and structural clarity.
Primarily opaque façade to reduce afternoon solar gain, with integrated mechanical zone and expressed timber bracing.
Controlled glazing balances daylight and heat gain, framed by exposed structural timber and extended roof shading.
Sloped roof profile enhances passive shading while exposed timber framing supports the extended overhang and open interior volume.
Section illustrates integration of structure, ducted mechanical distribution, and high-performance envelope within a compact building form.
