building control

[hem057]

what could we use to control motorized dampers for fresh air and return air to allow it to mix with supply air and maintain comfortable temp and also control fresh air to 7 story office bldg, and 4 large systems i.e. 12 large ducts to control

[Bill Tappin]

Honeywell makes control packages to fit your needs. Depending on what part of the country you live in dry bulb, enthalpy, or differental enthalpy, would work. You will need to know how maney square feet of damper area you are moving to get the right sized damper motor. Honeywell has components to fit almost any damper setup. They also have good drawings for wiring it up. You can even add CO2 sensor.

[hem057]

do you know what the model number is of this unit

[supertek65]

are the dampers currently electric actuators or pneumatic?

[Bill Tappin]

Your best bet would be a local a/c contractor (commerical) motor size to match damper sq.ft. critical from there it's only picking the logic module and sensors.

[hem057]

the actuators were neumatic, but it is best to switch them all over to electronic/electric
dampers are 3 ft high, 6 ft wide

[flange]

What you are talking about is easily accomplished using standard controls. the problem here is that we cant/wont tell you how to do it. Find a good local contractor who does this type of light commercial work and throw em a bone. There are many factors to consider other than just mixing in some outside air

[atruss]

You could hook up a mechanical linkage to a thermal actuator set at your temperature range.
Similar to the way Acutherm, Price, or Rickard uses VAV Diffusers.

These are the power units behind VAV technology. www.vernatherm.com

[hem057]

who is this flange guy, before you start slinging why don't you check credentials,besides, if you read the question, it does NOT ask how to do it; I am a contractor (hvacr) and have recently installed an entire warehouse with 14 walk in freezers using the cpc controller (2 actually, running three racks), that we are monitoring from our office, but I think using this to run these dampers is a little over kill for my customer, so just wanted to see what other guys are using now in the field that would be a computerized controller but won't blow their budget

[T Brewer]

Hi hm057 I'm siding with flange on this one. If you're from Ontario, then look for the Delta Controls or Automated Logic Rep in your area.

[flange]

I am a business owner, with over twenty years in the business. This is a simple economizer setup, off the shelf in a good controls supply house. For any commercial mechanic this is a breeze. The biggest issue is proper sizing of the actuators to meet the torque requirements of your dampers.

[shifferbrains]

what could we use to control motorized dampers for fresh air and return air to allow it to mix with supply air and maintain comfortable temp and also control fresh air to 7 story office bldg, and 4 large systems i.e. 12 large ducts to control


You might try asking this question in the controls section. You will get alot better response.


I am partial to Siemens Controls myself. You might take a look at there PXC controllers. They are programmable so you will have to have some knowlegde of Siemens PPCL Programming Language to set them up.

[hem057]

I am familiar with them operating a fresh air damper, then they have a barometric damper, so how will they operate the bypass and dump damper

[shifferbrains]

I am not completely familiar with your application but it sounds like a standard economy damper configuration plus outside air make up?

But then that is the beauty of a programable controller. It can do anything you can dream up. If you know how to program it.

[crab master]

I am with flange as well and I am a HVAC controls programmer and installer. This all could be done using existing pneumatics, but you need a good pneumatics guy to make this work. You also need to be concerned with static pressure in the building. If you go to electronics then you have a bunch of retrofit to do. This is actually quite complicated to do properly whether you choose to do pneumatic or electronic control in your scenario. Hire a contractor to do this and maybe they would be willing to work with you and have you install part of the stuff so you can learn a bit more about what all is going on, maybe they can do the first one and you do the rest. Anyway good luck.