What do social media and radiant floor heating have in common? Evan Williams, one of the founders of the social networking site Twitter, has recently listed his San Francisco home, which includes the eco-friendly system, on the market for sale. Realty Today reported that the property has been priced at $2.9 million. The three-level, four-bedroom townhouse sits on a gated lot and provided the founder with an ideal place to relax after helping run one of the biggest companies in social. Each of the levels in the home have a radiant floor heating included to promote greater energy efficiency and comfort.Radiant floor heating has the ability to be set in different zone, which allows a homeowner to keep spaces not used at a cooler temperature. Each floor or wing of the townhome can be set to a different temperature to meet the needs of those who are living in the space. However, this comfort feature also has a practical side to it as well.Unlike traditional heating systems that use vents, radiators or baseboard units to spread heat throughout a property, radiant floor heating applies warmth directly to a space. This allows a homeowner to not only feel more comfortable because of the direct contact with the heated floors, but it also reduces the chance of heat loss. The less energy being lost outside of a home, the less oil or natural gas that needs to burn to fill a space with heat.In addition, a radiant floor heating system works well in conjunction with other eco-friendly technologies. Realty Today reported that the Williams' home also features roof-mounted solar panels and remote shades to promote greater temperature control and sustainability.