Less expensive valve options?

twix

This is the best I could find for my 1-pipe steam radiators.

I'm planning on adding custom actuators operators/controllers to each of my units, but just the valve/adapter is expensive all on its own (around $100).

I understand I need:

- 1/8" radiator side male
- vacuum breaker
- actuator bit (controller not required right now)
- vent mount (for a straight pipe steam vent)

(Image removed due to TOS on price posting). Picture was of shopping cart with a Danfoss TRV Valve which includes a vacuum breaker, plus a cheap straight vent.

Are there other options that could save me some money? Or a place that has discounts on quantity? Or even used? Looking for ways to get the best price on about 8-9 assemblies.

Thanks.

ChrisJ

I wouldn't be using the vent you chose.
As far as TRV bodies, the Danfoss ones are good and I like the Macon's a bit better.

They cost what they cost.....but there's no way I'd put that vent on any part of my system.

I have however considered a system using a solenoid which is closed by a control based on room temp OR radiator temperature. I.E. it closes when steam gets into the last section.

twix

The $8 vent is the one you wouldn't touch? Or the $80 TRV?

ChrisJ

twix said:

The $8 vent is the one you wouldn't touch? Or the $80 TRV?

The $8 vent.
But that's also why I gave you an idea in my previous post. It eliminates the vent and the TRV body.
You'll likely still need some kind of manual valve to throttle air venting though for balancing.

Long Beach Ed

Why would you be adding these to each of your radiators? Something's wrong if you need them everywhere.

mattmia2

it is almost like you should select your vents to balance the system and only use TRVs in select locations where you have widely varying loads.

twix

I have however considered a system using a solenoid which is closed by a control based on room temp OR radiator temperature. I.E. it closes when steam gets into the last section.

A solenoid would be binary though, right? Open 100% or closed 100%.

I suppose one really doesn't NEED partial venting, ie, let the room temp get to where it's needed then shut the valve. Drop below a certain set point? Open the valve. Hmmm...

twix

mattmia2 said:

it is almost like you should select your vents to balance the system and only use TRVs in select locations where you have widely varying loads.

Yeah, I don't think every single one of the 9 radiators in our home needs this kind of control. But part of me also thinks if one has control, all of them should? Not super well thought out yet.

twix

Long Beach Ed said:

Why would you be adding these to each of your radiators? Something's wrong if you need them everywhere.

I'm planning on regulating certain rooms better based on usage (save fuel when not in them, for instance). I have a connected smart home that can help control all this.

twix

Here is a sneak peak into the test setup I have in the home office:

Long Beach Ed

A properly balanced and controlled system needs no thermostatic valves. You only use them in rooms where radiators are over sized or heat loss is very inconsistent. -- In rooms that often over-heat.

For example, a room that is subjected to substantial solar gain on a sunny day, but not on a cloudy one.

Or a room with a second heat source, like a gas stove or fireplace, occasionally overheats the room.

They are used to limit the amount of steam going to an individual radiator based on a very localized temperature. The thermostat should be doing this consistently throughout the house, with air vent sizing "fine tuning" for each room.

twix

Long Beach Ed said:

A properly balanced and controlled system needs no thermostatic valves. You only use them in rooms where radiators are over sized or heat loss is very inconsistent. -- In rooms that over-heat. They are used to limit the amount of steam going to an individual radiator. The thermostat should be doing this consistently throughout the house, with air vent sizing "fine tuning" for each room.

Why waste heat in 5 rooms that aren't used for 12 hours in the middle of winter? But then are needed again after 6pm to be warm and toasty? That's why Im' looking into this - it's an occupancy thing. I have properly sized main vents and rads.

mattmia2

twix said:

I have however considered a system using a solenoid which is closed by a control based on room temp OR radiator temperature. I.E. it closes when steam gets into the last section.

A solenoid would be binary though, right? Open 100% or closed 100%.

I suppose one really doesn't NEED partial venting, ie, let the room temp get to where it's needed then shut the valve. Drop below a certain set point? Open the valve. Hmmm...

That isn't how a TRV works on 1 pipe steam.

In normal operation the vent is open until the air is vented out of the radiator and the heat of the steam reaches the vent. The heat closes the vent. Once the radiator is full of steam the steam condenses on the inside surfaces of the radiator as the heat is radiated in to the room the collapsing volume of that steam pulls more steam in from the boiler. The vent stays closed this whole time. The vent is only used to start the radiator heating, once it is heating it is only open to the runout from the main, the cycle sustains itself as long as the boiler is firing.

A TRV on one pipe steam can only stop the radiator from heating at the beginning of a cycle, it can't stop it from heating once it is already heating. It is very important that the boiler cycles on and off on a one pipe system with TRVs. It is also important to have it rather well balanced to begin with, TRVs won't fix a poorly balanced system.

twix

mattmia2 said:

A TRV on one pipe steam can only stop the radiator from heating at the beginning of a cycle, it can't stop it from heating once it is already heating.

FWIW, I have smart home access and control on the heating cycle for our single thermostat. The Ecobee reports when it's actively calling for heat or not, which I can react to on any smart TRV.

Long Beach Ed

twix said:

Why waste heat in 5 rooms that aren't used for 12 hours in the middle of winter? But then are needed again after 6pm to be warm and toasty? That's why Im' looking into this - it's an occupancy thing. I have properly sized main vents and rads.

That's what the regular supply valves are for.

twix

That's what the regular supply valves are for.

So I should put an actuator on the supply valve?

Long Beach Ed

You can put motorized valves on radiators if you like. I, as most would consider it a waste of time.

Attempting to make a nine-radiator steam system behave like nine separate zones won't work without a constant supply of steam. You can do that, but you won't be saving much money.

Turning radiators on and off won't save you much money in a small steam system. It may actually cost you more because of the pick-up loads when restoring heat to cold areas.

ChrisJ

@twix
That's true... My TRVs definitely throttle the venting often rather than just stopping it.

But like Matt said lots of cycles are important.
I have TRVs on 5 out of 10 radiators but most of those were vented correctly without the TRVs.  I added them to the kitchen so it wouldn't get heat or as much if the oven is in use etc.  

They do often hold the radiators back some but it's mainly due to sun loading or oven use.

I have them in two bedrooms due to grossly oversized radiators so those they do hold back but those also are vented incredibly slow as well.


I mostly agree with what's been said here but TRVs can make a good system better.

But my system is also highly encouraged to run twice per hour and it makes a big difference.  

EBEBRATT-Ed

@twix

Shutting off radiators is one thing. Throttling a couple of them with TRVs is another. With radiators off you will be running an oversized boiler that can waste more fuel than you save.

TonKa

twix said:

This is the biest I could find for my 1-pipe steam radiators. I'm planning on adding custom actuators operators/controllers to each of my units, but just this valve/adapter is expensive all on its own -- $80! I understand I need: - 1/8" radiator side male - vacuum breaker - actuator bit (controller not required right now) - vent mount (for a straight pipe steam vent) Are there other options that could save me some money? Or a place that has discounts on quantity? Or even used? Thanks.

If you really want to tinker with the radiator vents, consider the ultimate in radiator "vents": a vacuum assisted system.

https://heatinghelp.com/systems-help-center/sustainable-steam-heating/

Intplm.

Careful. This might be a sight violation mentioning prices, Maybe ask how you can the best pricing rather than posting the cost.

ChrisJ

Intplm. said:

Careful. This might be a sight violation mentioning prices, Maybe ask how you can the best pricing rather than posting the cost.

No one is discussing labor pricing or anything else.  Retail pricing has never been an issue here that I know of.  You can get these prices anywhere your self and they're the same everywhere  so what's the harm?

twix

This is really hard to wrap my head around. It must be due to my simplistic understanding of my home's heating system.

If I'm not in a room (for an extended amount of time -- I don't want short cycles), why on earth would I want to pour heat into it?

I understand a TRV on the vent won't make a hot radiator cool, but won't it prevent a cool radiator from getting any warmer while it's throttled down? Doesn't that effectively cut that room's radiator out of the system and allow other rooms to benefit more from the steam?

Thanks for helping me work through this.

TonKa

If I understand you correctly, you want to control a one pipe steam system as if it were essentially a hot water system. I'll stick my neck out and say that you can't really do that without adding a second pipe, thus creating a two pipe steam system. Then, you could actually control the steam flow rate into a radiator.

Typical steam systems require rather large pipes. They would be hard to thread through a building. If you still want to pursue this, I would suggest contacting Gerry Gill and talk to him about the atypical minitube system. It uses relatively tiny pipes which are somewhat easier to thread through in existing building

mattmia2

TonKa said:

If I understand you correctly, you want to control a one pipe steam system as if it were essentially a hot water system. I'll stick my neck out and say that you can't really do that without adding a second pipe, thus creating a two pipe steam system. Then, you could actually control the steam flow rate into a radiator.

Even most hot water systems and virtually all forced air systems would have trouble with the equipment not being properly loaded if you tried that sort of microzoning. You'd probably have to have a buffer tank to make it work with a hot water system.

Basically you are not saving a whole lot of fuel by waiting for it to cool down then warming it up again vs just keeping it warm and the complexity of the system needed to do that at residential scale is likely to cost more than you will save in fuel since it will have an initial cost and ongoing cost as components break more often and cost more to fix.(but 20 years ago i would have thought the same way you do)