Attic vent louvers - motor control suggestions

[pbibm]

My house has an attic venting solution that works well, but is unusual. There is a 30" fan mounted in a gable, and that has been automated for a few years:



The problem I have is that there is secondary set of louvers mounted horizontally on top of the second floor stairwell. The fan will vent the attic, or optionally the whole house when the louvers are manually pushed open. You can see where this is going; I want to automate the motion of those louvers over the stairs.

I can provide power and remote control contacts to operate an actuator. Gravity pulls the louvers closed, what I need is the ability to pull one the rails that operate the louvers about 4" to open, and the either reverse that motion or let gravity do its thing. I found this video the louvers work when the fan is right on top of the louvers so you can see the motion

http://www.youtube.com/watch?feature...&v=hSIAUUkgocQ

Thanks in advance for any thoughts / ideas on the kind of device that can provide the motion to open the shutters via contact closure.

[Dave W]

Are you good, mechanically? A low RPM, high torque gear head motor with a 4 inch wheel and arm attached to your louver could work. The threaded shaft motor below would work well also. A nut on the shaft, attached to you louver would go up and down. Unfortunately this example only had a 3.5 inch shaft.

http://www.allelectronics.com/make-a...M-DRIVE/1.html

http://www.allelectronics.com/make-a...CHANISM/1.html

http://www.allelectronics.com/make-a...RNTABLE/1.html

http://www.goldmine-elec-products.co...?number=G16034

You should probably engineer some limit switch protection in case your timed "off" signal from Homeseer gets lost. If you used the 4 inch wheel with arm idea you fan louves would just cycle open and closed until you stopped it. But if you went the threaded shaft route it would get messy if the motor failed to turn off at the end of travel.

Just some DIY ideas.

[pbibm]

Interesting, thanks. I would rate myself average on the mechanical side and can figure some things out.

I see the difference in the two methods you are proposing. I do want to design it so an "On" signal completes an the open and a "Off" signal completes the close.

I would need 12 or 24 transformer and some limit switches to meet my design goals?

[BobSpen]

Paul,
If you don't have enough "suction" to pull the ceiling louvers open, naturally, you will probably not have enough airflow for a "whole-house" cooling effect(if that is what you are attempting). If so you need a bigger fan in attic or a lot less attic leakage.
BobSpen

[pbibm]

Thanks Bob. It does a pretty good job. The louvers were installed in the 1950s with the original fan and are designed to operated manually. The new fan i put in (in the picture) came with new louvers and I've thought about putting those in. I have thought about replacing the drive pulley to increase air movement a little

However there are times, like a night, I have the louvers opened without the fan so that air will rise out of the house into the attic and through venting. Conversely there are times when the fan will be running on the hottest days to keep heat from building up in the attic and radiating into floor 2. The louvers are shut then.

This is an ideal project for HA as its one of the few remaining "comfort" items were we have to remind each other... "go put the louvers (up/down)". With ultraweatherbug I can monitor conditions and head it off at the pass, I just need to figure out how

[Pete]

Paul,

Historically I used to have an attic fan which was set to automatically turn on with temperature. I know nothing of whole house fans.

I am though dealing with Mary Doolittle's whole house fan. It appears to be something similiar to your set up.

I see a very old control in the hallway and louvers there. Looks to be something from the late 60's? I can't tell.

I told her I would fix it? Thinking first of disassembling the wall switch in the hallway.

Do you have any pointers for me?

The house has hot water heat and originally was configured to 6 zones. It doesn't look like there is an AC in the house and Mary mentioned that the whole house fan would cool the house when it was hot outside.

[RAM]

Damper actuator

I've used a damper actuator for years on my whole house fan. There are many listed on Ebay that will work, some for less than $50.

[pbibm]

Pete:
I know more about this kind of set up than anyone should . These fans can be used from now until Octoberfor comfort and the rest of the year to remove moisture from the attic.
Here's what I have done over the years with this and it is a major comfort control device for us (or anyone) at this lattitude.

• Cut away and plated all original switches and timers in the living areas. Everything power and control wise is at the fan itself
• Replaced the original 1950s fan with a 2 speed model... about $350 from a hardware store.
  • Low speed for venting when the louvers are shut. Though I started with Ocelot temperature sensors, a simple dumb TempAlert on contacts is set to 80degrees and 36Degrees to run events
  • High speed controlled by HA transmitters when the louvers are opened. Any transmitter that they have will do the job In our house there are 3 keypads and one x10 keychain remote in the bedroom to turn it on/off
  • I use two inline lincs at the fan to control low vs high speed
  
  Make sure that there is a fuseable link to shut the fan off from fire (usually this is code).

Its possible. I think you will want to be the "chief engineer" and have someone else replace / service the fan. Its a heavy, ugly job combinef with extreme temperatures. I sent you an email. Call me so I don't drift off course on what you're looking for

[pbibm]

I've used a damper actuator for years on my whole house fan. There are many listed on Ebay that will work, some for less than $50.

Thanks Dick! I will check it out. I did some searches last night and found there was more out there than I imagined there would be.

Do you control your dampers with HA? If so, do you use contacts like an interface module or?

[Pete]

Thanks Paul!

Yes will do.

[Uncle Michael]

I've used a damper actuator for years on my whole house fan. There are many listed on Ebay that will work, some for less than $50.

+1 on the damper actuator.
Another option, but more work, would be to mount a second "whole house" ventilator fan over the louvers. When you want to vent the house, turn on the new fan (and the attic vent fan). Then the louvers will open by the pressure differential as designed. To just vent the attic, turn on the attic fan only. I've had a setup like that for some time and it works very well. (The attic fan motor burned out a few years ago, so I now use the house fan alone.) As a safety measure, I do not allow HS to turn on the whole house fan, but it is set to turn it off under a variety of conditions.

[pbibm]

Thanks UM. The setup works well with the exception of automating the dampers. How do you technically instruct the damper what to do? It needs 24vdc, which I get. Here is what i don't get:

• Does it need drycontacts to open / close to work the activator ...or..
• Do you turn on / turn off power to the 24vdc supply; on opens the dampers and off lets gravity pull them back down?

I am seeing them on ebay, but not seeing how to integrate automation to them.

[Uncle Michael]

Here is what i don't get:

• Does it need drycontacts to open / close to work the activator ...or..
• Do you turn on / turn off power to the 24vdc supply; on opens the dampers and off lets gravity pull them back down?

The damper controllers that I have seen have a motor that has two power terminals and an integrated switch. When you apply power to the 'close' terminals the motor activates until the switch reaches its limit and stops. If it's already closed, nothing happens. Similarly with the 'open' terminals.


The way I imagine this working is that you use a double throw relay to send power to one set or the other, depending on whether you want the louvers open or closed.

[Uncle Michael]

Paul,
I found this description in Wikipedia:

In one design, the motor is often a small shaded-pole synchronous motor combined with a rotary switch that can disconnect the motor at either of the two stopping points ("damper open" or "damper closed"). In this way, applying power to the "open damper" terminal causes the motor to run until the damper is open while applying power at the "close damper" terminal causes the motor to run until the damper is closed. The motor is commonly powered from the same 24 volt ac power source that is used for the rest of the control system.

[pbibm]

Thanks UM!