Cutting Museum Humidification Energy Costs by 80% Without Compromising Preservation

How a California Museum Lowered Costs while Protecting Artifacts with MeeFog

A museum campus presents unique HVAC challenges for facility managers due to the diversity of its collections. A single facility may contain paintings, drawings, books, sculptures, manuscripts, and photography. Fluctuating humidity can cause permanent damage through repeated expansion and contraction, and each material responds differently to humidity changes. can be a complex and ongoing challenge for building operators and mechanical engineers. A recent project at a world-renowned California museum demonstrates how modern humidification technology can reduce operating costs and improve environmental control. This profile examines the mechanical strategies used in the upgrade and practical lessons for protecting sensitive indoor environments efficiently.

Challenges of Museum Environmental Requirements

Implementation of MeeFog Humidification Technology

To address these issues, the museum replaced its expensive aging steam system with high-pressure MeeFog technology, resulting in more consistent humidity and lower expenses. Several phases were finished before others began, allowing operators to maintain strict climate control throughout the upgrade. Over 1,000 fogging nozzles have been installed, with more planned. The next phase will be a new hot water/chiller plant replacing the current chiller/boiler plant with an electric heat pump to supply hot and cold water, moving them toward their carbon neutral targets.

A general understanding of the mechanics of fog humidification systems can be valuable for mechanical engineers considering HVAC upgrades.

• Fogging pumps deliver water at 1,000 psi to a series of specially engineered nozzles. These nozzles are manufactured to tight tolerances, with orifice diameters ranging from five to seven thousandths of an inch.
• Water jets out of the orifice and hits an impaction pin, which breaks the water stream into billions of tiny droplets. The nozzles create as many as five billion super-fine fog droplets per second, with droplets averaging about ten microns in diameter. This fine fog evaporates quickly into the airstream, providing efficient adiabatic humidification to maintain humidity within the required 40% to 60% range.
• The system integrates with building controls for automated environmental management. Motorized ball valves stage the fogging and activate zones as needed. A variable frequency drive (VFD) on the high-pressure pump keeps pressure at 1,000 psi as valves open and close to meet building demand.

Humidification System Reliability and Water Quality Management

MeeFog supplied large reverse-osmosis (RO) water treatment systems to ensure the exact level of water purity required to protect both the air handlers and the supplied air circulating around the artifacts. Fog pump stations supply pressurized water to humidifier grids installed inside the museum’s air handlers. Each grid uses its own staging valve panel. This modular design allows accurate moisture introduction into the supply air stream and independent humidification control for each space. All RO systems and fog pump skids have built-in redundancy to eliminate the possibility of a component or device failure that could shut down the system and potentially endanger the artwork.