Zones or Nightly Shut Offs?

Brad White_203

I learn new things here every day... Not done yet!

Good point on the valves, Nicholas- despite being "handy", they do carry that risk. Thanks for pointing that out.

Bill_113

Zones or Partial Nightly Shut Offs?

I am new to steam heat and have a 2400ft2 bungalow with a one-pipe steam system. During the day, we spend 95% of the time on the first floor, but at night we spend 100% of the time on the second floor.
Therefore, I am wondering if there is a way to save $$ by sending nearly all the heat to the first floor during the day and then to the second floor at night? It seems right now we are being rather wasteful by heating the whole first floor all night when we really only need the bedrooms at a comfortable temperature.

Brad White_203

Best thing?

Your situation sounds like an ideal application for thermostatic radiator vent valves. I am partial to Macon OPSK's but there are others. Key is to have an integral vacuum breaker.

(Zoning one-pipe steam is a minefield of problems. Can be done but more often than not it just does not work. Not recommended.)

These will allow venting of air (and steam to enter the radiator) when the room is below setpoint. When the room is near setpoint or above, the air venting is slowed then stopped which in turn practically stops steam from entering the radiators.

These are really "high limit" devices and only say, "no mas!".

While I would not recommend that they be continually adjusted (they will not "Call" for heat but just allow it to enter when the boiler is on), these will dampen any over-heating and allow you to sleep in a cooler bedroom if you like.

Now, you could put them on just the upstairs to start, but if a cold night and the boiler comes on, you would wind up heating the downstairs too... Personally I would start with the upstairs, allowing that a well insulated roof often holds the upstairs at a warmer temperature regardless.

My $0.02

Brad

Bill_113

Zones or Nightly Shut Offs?

Just so I make sure I am following- your idea is to install tsv's on the first floor and then just crank them down at night to effectively shut those radiators down at a lower temp, thereby diverting the heat upstairs?

Brad White_203

Top Floor First

Use them in the spaces which tend to overheat or where you might ordinarily want them to be cooler. Tolerable but cooler.

Second floor first, see how you like them.

They also compensate for solar gain prominent rooms too, during the day of course

Bill_113

Zones or Nightly Shut Offs?

I guess I am not following. It doesn't seem like TSV's would be helpful in this instance. We don't have a problem with any one area overheating, I just want to stop heating (at least as much) the area we are not using during that portion of the day.

During the daytime, we are on the first floor. The first floor heats fine, but I don't like heating the second floor at all when we spend virtually no time up there. At night, we spend all of our time on the second floor. Again, the second floor heats fine, but I hate fully heating the first floor while we are upstairs all night.

Goals illustrated:

Daytime: Keep first floor temp @ 68; Keep second floor temp @ 55

Evening: Keep first floor temp @ 55; Keep second floor temp @ 67

Brad White_203

Short of

installing two separate boilers, one for each floor, I cannot recommend a way to re-pipe your boilers such that one set of radiators receives heat when the others do not. Zone valves are asking for trouble, happens time and again.

The TRV's are a less expensive way to help you get part of the way there, by keeping the upstairs at a compromise lower temperature. The principle is that the second floor, assumed to be well insulated, would be over-radiated chances are.

Also residual heat from the downstairs would also rise by convection to some baseline heating level even if the radiators are off.

(Try this last one- valve-off the second floor radiators and monitor the temperatures on the second floor. How low do they consistently go?)

Knowing that baseline temperature, the TRV's would allow "filling in" but using less energy than heating the entire house, for less cost than re-piping.

Imagine if your second floor never goes below 60 even with the first floor heating off? Happens.

Just a thought.

nicholas bonham-carter

shutting off radiators

instead of using the shut-off valve to turn off the radiators, try turning the air vent so that it points down. on hoffman vents, they are unable to release air while upside down. your vents may be similar.

the reason not to use the valve is because it may not shut off completely; and thus will release steam into the radiator, from which condensate will be unable to escape, leaving your boiler low on water. when you do turn on the radiator it may hammer.

if this method works and you notice some improvement then you will be better able to deceide whether or not to install the TRV one radiator or several.

one of the easiest and cheapest ways of ensuring economy of operation is as always-get your system in good operating condition:

1.proper main line venting, you are paying for the energy necessary to remove the air from the mains; don't rely on the radiator vents for this-they are to small!

2.proper low pressure-under 16 ounces[ you may need a vaporstat, and a good low pressure gauge.

3.a clean, well adjusted burner.

4.knowlege about these systems in general from a good steam book [available here].you will soon be doing all maintainance and problem diagnosis yourself! these old systems can be quiet, economical, and very comfortable, regardless of what people elsewhere say about them--nbc

Unknown

From what I can see there is no practical way to "zone" single pipe steam systems and make it work. In a single pipe steam system the running time (fuel use -burn time) is controlled by the thermostat. (ignoring the pressure and safety controls) and therefore everything is relative to the temperature of the room where the thermostat is located. The steam system will run until the set temperature of the thermostat is satisfied.

TRVs, with their individual thermostats, allow you to limit the heat coming into the room where they are located, however, have no (or very little)effect on the burn time. Basically saying the system will continue to use fuel regardless of what you do to the individual radiators until the heat requirements of the thermostat are satisfied.

I haven't researched it as yet but am thinking along the line of a dual thermostat setup. A thermostat downstairs controls the running time during the day and a thermostat upstairs controls the running time during the night. I'm not sure there is that much benefit to this other than not getting overheated upstairs during the night.
(which can be done by TRVs) The only possible fuel saving might be at night as the burn time would be just to satisfy the upstairs thermostat. As you can come close to this by experimenting with the raising/lowering the downstairs thermostat I question whether playing with the dual setup is worth the time or money.

This is the sort of thermostat I'm looking at:


http://www.totaline.com/dl/P474-1100RF OM.pdf

As I say I haven't really thought this out yet and haven't even gone as far`is figuring out if this unit is compatible with steam. One advantage is that it is wireless so I could move it about to get the optimum thermostat location for the total system.

As Brad is an heating expert, I'd appreciate any thoughts he has whether the dual thermostat idea has any practical use.

LOL..Another possibility is to just do away with TRVs and wear the wireless thermostat on a strap around your neck and that way the boiler would keep which ever room you were located in at the temperature you desired!