IDeAs - Natural ventilation / radiant heat

Daylighting	Natural ventilation/radiant heat	Ground Source Heat	Integrated design
Advanced Glazing & Insulation	Energy-saving office equipment	Renovation Not Green-field
Energy-efficient lighting	Energy Control & Monitoring	Building-integrated photovoltaics

When designing a high performance HVAC system, it’s important to understand what conditions you’re optimizing for. Heating and cooling loads have been driven by how much energy is needed to keep inside air temperature at a set level—the same temperature 365 days a year. In reality, people are happier with some variation. Our bodies have a hard time adapting to extreme contrast between inside and outside temperatures. Most people find it natural and comfortable to have slightly warmer inside temperatures in the summer and cooler temperatures in the winter.

The IDeAs Z² Design Facility's innovative heating, ventilation and air conditioning (HVAC) systems are designed to use significantly less energy than standard systems. The HVAC design strives to maximize performance, energy efficiency and indoor air quality, while keeping the construction costs comparable to more traditional designs.

The energy efficiency for the HVAC and envelope is estimated to be about 40% below California Title 24, 2005 requirements.

	Radiant Floor System The Radiant Floor topping slab covers cross-linked counter flow polyethylene (PEX) radiant tubing system for both heating and cooling. The slab itself contains 50% fly ash to increase its recycled content. Using water to heat and cool a space with a radiant system uses less energy to provide the same amount of conditioning compared to a forcedair system. This is due to the radiant effect created by the floor temperature variance between the occupant and the floor itself. By comparing the floor temperature to the room air dew point temperature and adjusting the temperature accordingly, floor condensation can be avoided. If dehumidification is needed, the air handling system automatically provides it.
	Operable windows and doors Operable windows and doors installed throughout the building allow the occupants to tailor their comfort levels through tuning the openings. However, when outside air temperatures are too cold or hot and the windows or doors are not utilized. The dedicated outside air-handler provides the required ventilation primarily for the large open studio area. Chilled or hot water supplied by the heat pump to the air handler also helps regulate user comfort by conditioning the air delivered to the space.
	Radial Tubing Exposure Radiant floor systems typically use relatively higher water temperatures for cooling and lower water temperatures for heating allowing the equipment providing the water to operate more efficiently.
	Displacement Vent For displacement ventilation, vents are placed low and are relatively large, compared to traditional forced-air systems. The objective is to bring in clean air low and slow. Entering air is slightly cooler than ambient, which makes it denser than the ambient air so it says low in the space. In addition, people create a heat plume, causing air to move up around them. If for example, they cough into the air, their germs move up into the open space, away from their co-workers. Therefore spaces with displacement ventilation allow occupied air to be cleaner and healthier.