Splitting zone with shared lines

davidv851

Hello. I'm planning on some changes to my heating system (hoping to save on heating costs this winter), and I want to see if what I'm planning will work (or, more to the point, what issues there may be in doing things this way). As of now, there are 2 zones on my ~3500 sq foot home, hot water / copper baseboard. During the winter / evenings, we really only need to heat the bedroom. I have a programmable thermostat downstairs to allow that, but there are 2 bedrooms upstairs on the one zone / loop, and a single feed / return feeding them. Would I be able to install zone valves upstairs, keeping the shared feed and return? I realize that reducing the zone size too far can lead to noise / erosion / etc, and that I may need to adjust the thermostat / hydrostat settings to avoid short cycling the boiler and maintain flue temperature, but is there any hard and fast reason not to do things this way? I don't mind work / fine tuning things, but if I can I'd really like to avoid running new lines from the basement to the second floor.

Jamie Hall

In answer to the hard and fast reason... not really. However. First, you may wind up with one very small zone (that one bedroom) and, unless you have a buffer tank, the boiler will short cycle. Second, unless you have a delta T pump on the zone you are splitting, you will be overpumping when just the one zone is open, leading to a low delta T and high return temperatures.

Third, and perhaps most important... you are really talking here about a form of setback, and setbacks usually (there are exceptions) don't save much energy...

NY_Rob

Just close the damper on the baseboard in the bedroom you don't want to heat. It will still keep it somewhat warm and no plumbing modifications needed.