Powered Damper system for HVAC

One of the potential upgrades we're looking for for our HVAC system is to go to 2 zones, upstairs and downstairs. The stack for our HVAC output splits off right above the fan and goes into a single duct for upstairs, a large one for downstairs, and then 2 smaller ducts for other downstairs locations.

I got a quote for installing a powered damper system into all that, and it came back $2k. Now, I don't know how much the dampers themselves cost, but I know I could handle the control part myself (dampers just work off a relay, right? So anything that will throw a relay will control these things?).

Is it possible to get powered dampers the correct dimensions for my HVAC system and put these in myself? Really I just cut away the cut and insert it in, power and control, right?? Or is it better to leave it to the pro's?

http://www.resconsys.com/

I used go do building automation systems with Delta Controls, my uncle asked me the same question, so I showed him the company I linked above.

This company has controllers as well as the dampers. You would more than likely want to get the Normally Open dampers so in case of a power failure the dampers remain open and you dont have a cold weather nightmare on your hands. The idea behind the dampers is you apply the 24VAC to the damper to close it, remove the power to open it. I would think any relay would do that for you, you would just need to program a process to do it via a thermostat.

Ryan

beelzerob said:

One of the potential upgrades we're looking for for our HVAC system is to go to 2 zones, upstairs and downstairs. The stack for our HVAC output splits off right above the fan and goes into a single duct for upstairs, a large one for downstairs, and then 2 smaller ducts for other downstairs locations.

I got a quote for installing a powered damper system into all that, and it came back $2k. Now, I don't know how much the dampers themselves cost, but I know I could handle the control part myself (dampers just work off a relay, right? So anything that will throw a relay will control these things?).

Is it possible to get powered dampers the correct dimensions for my HVAC system and put these in myself? Really I just cut away the cut and insert it in, power and control, right?? Or is it better to leave it to the pro's?

Click to expand...

Be aware that your furnace depends on a certain amount of air flowing through it to function properly/safely. If you restrict it too much the heat exchanger in the furnace could overheat and crack causing problems and risks of carbon monoxide poisoning. You need to remember that when you design your modifications.

RAM said:

Be aware that your furnace depends on a certain amount of air flowing through it to function properly/safely. If you restrict it too much the heat exchanger in the furnace could overheat and crack causing problems and risks of carbon monoxide poisoning. You need to remember that when you design your modifications.

Click to expand...

True, but our risk is lower than most, this is just a heat-pump system.

Ryan Nichols said:

http://www.resconsys.com/

Click to expand...

Well, that's familiar, as my HVAC controller is an RCS TR-15. It wouldn't do damper control, though.

The RCS stuff looks fine, except that one damper is going to for sure have to be rectangular. Also, all of my ducts are fiberboard, not metal...do you think that makes a difference?

beelzerob said:

dampers just work off a relay, right? So anything that will throw a relay will control these things?

Click to expand...

At the moment I am diagnosing what I think is a stuck-open damper, and I observe full-time open or close voltage from the HVAC controller (works something like a Tortoise switch machine). The actuator motor has an internal limit switch (or switches) in each direction that stops the motor at (ideally) the full-open or full-closed positions.

So I share Rob's interest in parts sources and general information. And my damper unit is rectangular, in all directions.

beelzerob-

I used the RCS zone controllers and I did not have any problems. You just buy the size motorized dampers you need. I used both round ,rectangle and square



Steve

Steve, you used rectangular and square RCS dampers? Because I can only find round on their site.

It's a shame this TR-15 doesn't support dampers, as that would really be handy. But I'm willing to handle the control myself instead of shelling out for a new thermostat.

Now here's a bonus questions....I have a rain8net controller I haven't used AT ALL for its intended purpose (irrigation valves). Now, aren't irrigation valves at 24 volts also? If so, then (forgive the redneck hick sound of this) but couldn't I use that rain8net to power/control the dampers instead of having to find some other control system?

Beelzerob-

I know the dampers are 24 VAC. I am not sure about the sprinklers.

Any idea how many zones you want?

You can still use the TR-15, you just need a zone controller and you can use you existing TR-15.

I think this is the one I ordered.

http://www.automatedoutlet.com/product.php?productid=502

That post about the TR40 is a steal, I should buy it, but I am low on $$$


let me know if you have any questions


Steve

Ya, that IS a great price for a TR40...but I've gone nearly broke buying great deals...

$290 for a zone controller? Whew...not today. I had just hoped to find a thermostat with it built in to save me some integration problems....but I already have thermometers throughout the house, and if controlling dampers is just throwing and opening relays, then I've got my own zone controller.

From the Rain-8 2-Way X10, Sprinkler Valve Voltage & Current: 24v AC, 250 ma max (with supplied transformer)
For the dampers:Motor: 24VAC, 500mA. Two wire. Heavy duty synchronous motor

So, you would need maybe a bigger transformer if that Rain8 would take it..

The way the dampers work is to determine if the temperature has been met, then apply the voltage. To be honest, It would more than likely be a pain to make your own to control those, unless it was a switch or something manually.. If you use the zone controller it will keep the unit running until both zones are satisified. The 2 zone controller is like 180 or so..http://www.smarthomeusa.com/ShopByManufacturer/RCS/Item/ZC2S/, but then off course you would need the other thermostats.. the ones you have I dont think they are compatiable with the zone controller..

For the square ducts... http://www.climatedoctors.com/Items/hone25...0Blade%20Damper Is an example of one. All you need to do is find a damper that is 24VAC ...

You will need a bypass damper, or what I did at my uncles house since he had a basement area, was I just installed a couple vents down there on the main duct so that the unit was either heating or cooling the basement even when the dampers where closed, thus still allowing the unit to release the air into the basement and not cause any problems.

The quote you got for the 2,000 more than likely included his labor and parts. When you install the damper, you need to cut your duct, then install the damper at that point. You will need to use a duct crimper on one side of the new duct to install the damper there, then run a control wire to where ever the control source is. I did a 6 Zone damper install on his house and with all the duct cutting,etc it took me 9hrs to do.

Sorry for the ramblings, if you have any other questions i can try to help.

I stand corrected:
Thermostats for use with the ZC2S
The ZC2S works with most ELECTRONIC thermostats (Honeywell, White Rogers, Lux). Use only thermostats
that are either battery operated or that use both sides of the 24VAC power (they have R and C terminals)
from the HVAC system
DO NOT USE POWER STEALING THERMOSTATS!
Typically these thermostats “steal” power from the “W” or Heat connection on the HVAC system. THESE WILL
NOT WORK WITH THE ZC2S ZONE CONTROL UNIT.
It is also recommended that you do not use older style mechanical thermostats that use “anticipator” circuits as
these will not function properly.
Thermostats connect to the zone control unit terminals the same as they would connect to the HVAC system.

I just found the manual..

Well, I won't push the rain8 any further down the road it's not supposed to go....

I'm coming to realize I should probably be heating my basement, even if no on is down there. I think it'd make a difference as far as the floors above being warmer, and that might make a noticeable difference.

Ok, this idea isn't quite dead yet....

I've come to realize that I really only need 1 damper. The upstairs is the problem, and only in winter. So if I cut off the upstairs (which only requires a single damper to do), then all the heat is directed downstairs where it's needed.

I would only need to cut off the downstairs when it came to cooling in the summer, and cooling is not a big problem for us.

So now that I think I can get by with only a single damper, this becomes more affordable.

Looking at the duct, at about 4 feet from the main stack, it converts from a square duct to a round duct. So I think there I could put a round damper, like the RCS ones. I'll have to measure the diameter to see if it fits. Now a couple questions:

1) The RCS dampers come in 2 varieties, 2 wire and 3 wire. If I understand correctly, 2 wire means you power it open, and I guess the power being applied KEEPS it open, and if you remove the power than it closes via spring. 3 wire means you user power to open it and power to close it. Any particular recommendations? While it would seem to be handy that in case of a power outtage the damper will open in a spring-system, that really doesn't matter all that much since it's not like the heat pump will be operating in power off.

2) I'm getting a quote from the local HVAC company for an install of JUST the damper, and I'll make all electrical connections. So if I go for that, then that means I need to supply a 24V power supply to the connections, right? I'm a relative noob at relays and power supplies....assuming I have a secu-16 that has relays in it I can control, then how does this wire all together so I can control the damper?

3) I mentioned using the rain8net irrigation controller I have, since it provides 24v power (to control irrigation valves), but Ryan pointed out that the amps provided with the standard transformer probably wouldn't be enough. Is it asking for big trouble to find a 24v/500ma transformer and use that with the rain8net to control this damper? Or is it simply not that easy. If the rain8net won't work, then what piece of equipment am I going to need to provide that power? Does the standard zone controller I've been pointed to handle all of that? (power and relays?)

4) Does either 2 wire or 3 wire operate even when the fan is on? Are these things supposed to work even when the air is flowing all around? Seems like that'd be a lot of pressure on it, whether spring or damper.


My goal really is to use my own relays (secu16), temp sensors (datanab32), thermostat (RC15) and software (CQC) to control when the damper opens and closes. I'm hoping that'd be the case, and that all of this investment might start actually SAVING me money.

beelzerob said:

1) The RCS dampers come in 2 varieties, 2 wire and 3 wire. If I understand correctly, 2 wire means you power it open, and I guess the power being applied KEEPS it open, and if you remove the power than it closes via spring. 3 wire means you user power to open it and power to close it. Any particular recommendations? While it would seem to be handy that in case of a power outtage the damper will open in a spring-system, that really doesn't matter all that much since it's not like the heat pump will be operating in power off.

2) I'm getting a quote from the local HVAC company for an install of JUST the damper, and I'll make all electrical connections. So if I go for that, then that means I need to supply a 24V power supply to the connections, right? I'm a relative noob at relays and power supplies....assuming I have a secu-16 that has relays in it I can control, then how does this wire all together so I can control the damper?

Click to expand...

On this one point -- Since the secu-16 has only single-throw relays, I would think you are overall better off with a 2-wire damper. This is a straightforward connection of the power supply, the damper, and one of your relays, all in series.

If you go with a 3-wire damper, it gets complicated -- you will need to introduce another external relay (an SPDT-type) -or- you can employ two secu-16 relays, controlling them always in opposite directions. In this latter case, if something goes wrong with your logic or hardware, you have the potential situation of trying to open and close the damper simultaneously.

You have a return upstairs?

What are you tring to damper the vent (output) or return (input). I'm sure you can imagine how doing both would have a much more massive effect.

I think the Ocelot and SECU16 is an ideal solution, however I wouldn't get CQC involved in it. The Ocelot is a real deal RTOS PLC, lightyears ahead of windows anything in the reliablity department. Just take your time and learn some cmax it won't take you too long and plenty here to help ya.

Keep in mind you will need external relays with the SECU16, it will support your temp sensors and damper outputs but it's outputs are low current.