Thermostat vs. timer in an apartment building

benno

I'm part owner of a residential, 5 story loft building. We are improving it's operation and currently are looking at the choices available for sending heat to all floors, given that the current system provides uneven heating, more to the bottom 2 floors than the top 2.

In looking at availability, it appears that the choice is between a thermostat and a timer. With a thermostat, it appears that placement is the main issue but the choice of sensors, internal and/or external is also key. Issues relating to a timer include providing either too much or too little heat depending on the outside temperature. Timers appear to be a solution to thermostat placement but with little sensitivity to the actual, weather dependent needs.

We have a single pipe system with risers in all four corners of the building with venting at the top of each riser. I'd appreciate whatever help you may be able to provide in our decision-making process.

jumper

I recommend timer. But you have to take in account how long it takes to warm up building. You want to be warm when you get up in the morning and when you get home in the evening.

You can try slower vents on rads that warm sooner.

KC_Jones

If the heating is uneven on a steam system, the control system most likely isn't going to fix that. The most likely problem is a venting issue.

Jamie Hall

As @KC_Jones says -- venting. You have to get the venting right and the system balance before you even think about how you are going to control it.

What vents do you have at the tops of your risers? They should be adequate to get the air out within two or three minutes of steam being raised in the boiler. Or, put it another way -- if you are watching the boiler, and it starts to create steam, if you can climb the stairs and get to those vents before they close, you don't have enough venting.

Then once you get enough venting on the risers, try slowing the vents on the radiators on the floors that heat faster.

You may find, even with good venting, that you still have problems, in which case I would seriously consider using thermostatically controlled vents on the radiators which heat too much. But don't go there until you've done what you can with regular venting.

nicholas bonham-carter

Definitely check on the main/riser venting first. The only question i have is whether to put adequate main vents on the mains in the basement, and then an additional one on top of each riser.
you want enough capacity to enable the air to escape with a very low resistance, (2 ounces back pressure on a 0-3 psi gauge).
post some pictures of your boiler and its piping for use to comment. Many Heatimer controls were installed as a band aid for system problems, and actually made the symptoms worse.
Maintaining a constant lower temperature is better than using setback of higher temperatures interspersed with lower.
With the Honeywell VisionPro thermostat, a remote sensor can be placed in the coolest top corner of the building, using only 2 wires. The thermostat head itself can therefore be put into the basement, away from prying fingers!--NBC

John Mills_5

Get a Red Link Vision Pro stat and can get wireless remotes to average the temps.