Programmable Thermostatically Controlled Valves for Two-Pipe Steam Radiators

JASSS

First time poster here. I would like to install a thermostatically controlled valve on a two-pipe cast-iron steam radiator. I am looking at the Honeywell Braukmann V110D1013 straight valve. I would like to install a programmable controller to allow the space temperature to be set back 4 of 7 days per week. Honeywell has the HR90 actuator, but the specification sheet states it is only rated for hot water and does not even appear to be able to be physically mounted to the HW V110D1013 without an adapter that I have not been able to source. I contacted several other manufacturers and none seem to have an offering with setback capability. Thank you in advance for any help.

Jamie Hall

What valve is on the radiator now?

Looking around at what's out there, it looks as though your best bet is going to be to use a valve such as you suggest -- although other powered valves exist -- and control it with a separate, programmable thermostat. This will give better control anyway, since placing a control thermostat more or less directly on the radiator it is supposed to be controlling really doesn't give good results.

nicholas bonham-carter

Are the setback days contiguous, or interspersed throughout the week? How deep a setback are you considering?
Most people here are not convinced that a short term setback will yield savings; however for 4 days straight, there may be some benefits.
Is the system evenly balanced with all radiators heating up at the same time?—NBC

JASS

Sorry for the delay in responding; I was travelling and out of pocket. Answers to questions are:
Jamie Hall: There are not any type of control valves on the cast iron radiators now, just a manual isolation valve. The problem is I can't find a manufacturer that has the controller I need. The Honeywell Braukmann HR90 actuator is only rated for hot water and I need it for a low pressure steam system. Can you provide the manufacturer and model number for a valve and controller/actuator rated for steam service. I can source the programmable thermostat and any transformer myself. I know the thermostat needs to located as far away from the radiator as possible to avoid inaccurate readings.
Nicholas Bonham-Carter: The setback is 4 days continuous. Right now, I manually close the isolation valve on the steam supply and then manually open it four days later. This works perfectly with noticeable cost savings. I am just looking for a way to do this automatically. The space is a basement with 80 percent below grade and 20 percent above grade and there is no chance of the space freezing. I have been closing the valve manually for the past several years and the space never falls below 55F. The radiators/system is evenly balanced and all radiators heat up at the same time. I just want to close/open the valve automatically rather than doing it manually. Thanks to all for your knowledge.