Evaporative Cooler Replacement, down draft adding a damper??

[Tim Fastle]

I currently have 2 large, fairly tired, Master Cool down draft evaporative coolers on our flat roof. We are getting a new roof (TPO) soon and I plan to replace the evaporative coolers as part of that process. Neither unit has a damper to to actuate or insert for winterization (instead, I guess the covers are doing that job - and probably not real well). I am going to have the roofers install new roof jacks. I am considering going to side draft units so I can have a damper but would prefer staying with the downdrafts. I have not dealt with duct work interfaces a lot so thought I would ask others that have and know much more than I do. Is there a clean way to use the down draft units and still have a damper? The problem I see is that there is no access with the down draft (which also is a problem with maintenance if you have an air leak). I did look quite a bit online but could find nothing that dealt with this issue. I did run across "Downdraft Barometric Dampers" - might that be a good option? Do they work well and maintenance free, since there's no real access to it? I plan to make custom stands so raising the unit 5-10" would be doable. Any input (or a suggested document or site that cover) or thoughts would be greatly appreciated. I really would like to do this right and have a clean setup when finished.

On a side note, I think I am going to go with basically the same Master Cool (they seem to be good) units that I have unless someone would suggest a better option?

Thanks!

 

[Fitter30]

6x6 treated wood have roofers roof over them set cooler on sheet metal caps over the 6x6 ' s. Side discharge with stainless opposed blade class 1 damper with electric actuator. Damper has rubber seals for close off . Insulated exterior duct either aluminum or stainless sealed.

 

[Sponsor]

 

[Tim Fastle]

That would indeed be a very clean install. I have decided that I will go with a side discharge. WIth this design I assume I would want the damper at the discharge opening and the 90 duct elbow attached to it? The discharge opening is 19.75 x 19.75. Not being a HVAC guy, where might I get such a damper and do they come in many sizes? While a electric actuator would be very clean, the damper being open the entire cooling season would be acceptable as well (or normal in this area anyway). Most of them around here have a sheet metal "damper" you put in when you winterize and take out when you open them up. I assume there are manual dampers similar to the one you described that would work and be much cleaner that the piece of sheet metal slid in. I like the 6x6 and roof over it idea. Thanks very much for the reply.

 

[Fitter30]

Their are several damper manufacturers here's one. Just Google stainless opposed blade clasds 1 damper. Might find something on ebay.

Halton UTK - Multi-blade airflow management damper

Rectangular multi-blade damper, Halton UTK. The shut-off tightness is class 1 according to EN 1751. Contact Halton for further info.

www.halton.com