Tuesday, December 18, 2007

The Heat is On.

The heat is actually finally on. The floor is warm and Butters is a happy kitty. It was a pretty dang complicated assembly process involving some 150 copper solders (no leaks), 75 threaded black pipe connections for gas (many of them manually threaded with my tired arms), many feet of wire and some fancy wiring, 2 thermostats (and 2 more to come), PVC pipes through the roof for the exhaust and a whole lot of figuring.

Here are some of the technical details which you may or may not find interesting. It's a really elegant system. The building is divided into 4 zones each with it's own thermostat, zone valve and series of tubes. If a particular thermostat calls for heat the zone valve controller opens up the valve for that zone which allows water to run through the appropriate tubes, it switches on the secondary pump and tells the boiler to turn on (if it's not already on heating another zone). The boiler has a bunch of sensors and is a pretty sophisticated little unit. So the boiler is now burning gas and heating water in a hurry which is flowing through the floor tubes in the appropriate zone. The water starts out hot and returns cooler having given off some of it's heat to the floor. As the difference between what's coming back and going out gets closer to a programmed differential the boiler modulates it's heating so that it only heats as much as is required to maintain the right temperatures. Then eventually the thermostat says whoa! and the whole system just mellows out for a while, a long while. It can take like 3 hours for the air to drop just 1 degree once the concrete slab is heated up. There's also an outdoor sensor so that the system can predict rising/falling temperatures and disengage/engage early if needed so there's no lag.

Pictures with labels:

The important thing to know is that it keeps my toes warm and it makes butters curl up like a happy cinnamon bun.