World Springs at Grandscape in The Colony

Project Overview

The World Springs at Grandscape location is a luxurious retreat featuring 48 pools and spas, offering elevated customer experience through geothermal innovation and a seamless blend of spa and sauna, retail, and food and beverage services. The project emphasizes sustainable mechanical design while enhancing guest comfort and reducing the facility’s environmental footprint.

Highlights

New Construction
Entertainment
Geothermal

Project Team

Owner – WorldSprings

General Contractor – ARCO/Murray

Architect – Harrison French and Associates

Project Details

Based in The Colony, this World Springs location is composed of five buildings supporting pools, spa services, retail spaces, yoga rooms, and food and beverage offerings, including a walk-up bar and a full-service bar with back-of-house operations. The facility’s mechanical systems were designed to support the dynamic needs of these diverse spaces while minimizing energy use and environmental impact.

The main administrative building and a portion of the pool operations are connected to a ground-source heat pump system with 70 geothermal bores, each 400 feet deep. Heat is transferred seasonally to optimize energy use: the heat removed from the main administrative building during the summer is used to heat spas, while in cooler months, heat is extracted from the ground to heat the administrative building and spas. The overall facility design is a hybrid system, with supplemental air-cooled chillers and condensing boilers used for additional flexibility.

Mechanical Design Overview for the World Springs at the Grandscape in The Colony

Water-to-water-source heat pumps, with centralized pumps equipped with variable frequency drives (VFDs), modulate operation to meet changing load demands.

The pools, operating between 90°F and 104°F, are equipped with dedicated heat exchangers to maintain pool and spa temperatures without mixing water across pools. A buffer tank was incorporated into the hydronic design to handle load variability efficiently and reduce boiler cycling.

High-efficiency condensing boilers support the pools take advantage of the efficiency gains that are available with the lower pool and spa water temperature set points that are typically not available with the hot water supply temperatures needed to heat buildings. R410A refrigerant was selected for all HVAC systems, aligning with sustainability goals.

The facility also features 100% outdoor air ventilation with total energy recovery wheels in locker rooms to ensure occupant comfort while maintaining energy efficiency.

Energy Efficiency

World Springs’ geothermal system exemplifies cutting-edge energy efficiency by leveraging heat exchange between pools and ground-source heat pumps to reduce energy consumption. Centralized VFD-controlled pumps and a buffer tank ensure equipment operates at peak efficiency, accommodating the facility’s dynamic heating and cooling loads. High-efficiency condensing boilers and air-cooled chillers provide backup while minimizing energy waste. An Energy Management System (EMS) monitors the energy consumption of the pools and fully automates the water side of the design for the portion of the facility served by the geothermal system.

Indoor Air Quality

To enhance guest wellness and comfort, the design includes 100% outdoor air systems with total energy recovery wheels in high-occupancy areas and areas with high exhaust requirements such as locker rooms. These systems improve ventilation and maintain optimal indoor air quality while conserving energy.

Innovation

The integration of geothermal energy for pool heating and cooling represents a novel approach in spa and recreational facility design. This system not only supports energy-efficient operations but also demonstrates a forward-thinking commitment to sustainability by reducing reliance on traditional fossil fuels. The use of buffer tanks to manage dynamic pool loads and the separation of heating and cooling demands across buildings further highlight the project’s innovative design solutions.

Operation and Maintenance

The mechanical equipment is distributed across three accessible locations to simplify maintenance. The reduction in boiler quantity, coupled with the modular design of the system, eases servicing and ensures reliability. The geothermal system and centralized pumps are designed to operate efficiently and predictably, minimizing downtime and operational complexity.

Cost Effectiveness

From a lifecycle cost perspective, the geothermal system offers significant energy savings by efficiently using heat that would have been rejected to the atmosphere with traditional air-cooled air-conditioning units. While the initial investment in water-source heat pumps was higher than conventional rooftop units, the operational savings and reduced carbon emissions make it a cost-effective solution over time. The buffer tank further enhances cost efficiency by allowing smaller, right-sized equipment to be used instead of larger, costlier alternatives.

Environmental Impact

The facility prioritizes decarbonization by relying on geothermal energy and high-efficiency heat pumps to reduce emissions. By eliminating reliance on traditional chillers and boilers, the design minimizes the facility’s carbon footprint while using environmentally friendly refrigerants. The geothermal system’s seasonal heat exchange capability maximizes energy conservation and demonstrates a commitment to sustainable building practices.