Some folks don’t have central air – meaning that they have individual units which are used in individual rooms to heat/cool the area. This makes it hard to maintain uniform temperatures throughout the building – one room may be warm, another freezing cold. Trust me, I’ve lived in this sort of house.
Many of us do have central air (I do) – and boy, is it a nice convenience. Air is pushed out from the air handler all throughout the house via ductwork running through the walls, floors, and ceiling. This helps brings the house closer to a uniform temperature – but anyone who lives in a central air home knows this is still not the case. Whatever floor the air handler is closest to will get more air forced through the vents and b/c heat rises the upstairs will oftentimes be warmer than the downstairs during the summer – and I mean significantly warmer.
There is a way around this small difficulty – multizones. This involves multiple thermostats – one in each “zone” of the house. The air handler then sends air to the zones that need it – and turns off air to those areas when the thermostats indicate the desired temperature has been reached.
Pretty cool – but also pretty expensive. I thought there must be a better way – but no one seemed to know of one. It made sense to me that one could have registers (the vents that air comes out through) which were “intelligent”, using a thermostat in that room that they wirelessly communicated with and then opening or closing the grill of the register based on whether the idea temperature had been met.
I’ve finally found a company that makes these devices. I haven’t had a chance to try one myself (but they are on my wishlist now!). The company is called inova Products and the product itself is known as Activent. The vents cost $50/ea. and according to the website will pay themselves off within a year. Go take a look for yourself, and if I can get my hands on some, I’ll be sure to let you know my thoughts on their actual performance as well.