What I really need is just the bladders and the pump. I'd like to have Homeseer control the action through my Ocelot/SECU16.
Is the inflatable kind any more affordable than the power dampers? Trying to retrofit a power damper into my ducts is going to be terribly difficult. Dropping a bladder in a duct sure sounds nice and easy.
Any experiences? Any online sources?
I don't know if these folks are still in business but you might want to try contacting:
RetroZone,Inc.
4103 Pecan Orchard Drive Parker, TX 75002 Phone: (972) 633-8104 Fax: (972) 633-8973The bad news is their website seems to be down.
Regards, Robert L Bass
I have seen a few of the bladder dampers listed on eBay while searching for the motorized vane type. They were pretty cheap.
It is not that hard to add round motorized vane type dampers into galvanized ductwork. As I recall, 8 inch variable displacement vane dampers were around $100 at the local HVAC distributor. Simple 2-position dampers sometimes show up on eBay at pretty good prices.
Jeff
If I had accessible ductwork, I'd be down on that. The large duct to feed my lower floor exits the air handler straight down. Accessing it would require removal of the entire air handler. It's a very tight, clean installation which is absolutely impossible to work on. I could knock a hole in the wall it comes down through easy enough, but I have developed a deep and abiding hatrid of drywall work. So that's a last resort for me!
I'll dig around ebay. Thanks.
Have you tried your hand at plaster-on-lath ? Horsehair on brick? *Much* more challenging ;-)
More seriously, what did you do to determine that your furnace blower can handle the increased back pressure that is developed when you close off ducts/outlets?
I ask because one of our furnaces died this week (2 days after its annual $90 inspection/tuneup ;-( so I am in the process of rethinking that part of the HVAC system.
Seems to me that the new variable-speed, DC blowers could handle variable back pressure more easily than legacy 1-speed, AC blowers.
With the recent rise in natural gas prices in my locale, the cost of electricity for residential heating became about 10% lower than natural gas (assuming 90% efficiency) so a major redesign may be in order.
When I ask the local HVAC contractors about zoning the system, they tend to group into those who respond with a look of near panic and those with that 'ca-$ching' grin ...
... Marc Marc_F_Hult
The ones I saw on eBay were for branch ducts, not a main duct. Marc is right about backpressure. You may have to add a barametric damper to dump air if the pressure gets too high. We have a dual system that only runs one blower when the need is low. The controller is smart enough to partially open some dampers to prevent too much backpressure - probably by monitoring exhaust temperature.
Ah... drywall. I put up 115 sheets of the stuff here - mostly 12 footers. The fun part was calculating all cuts in a spreadsheet to virtually eliminate any waste.
Good luck with your project. I'm convinced that an efficiently used zoned system will quickly pay for itself.
Jeff
Zoning systems can be made to work very well....
Problem, and a sad part of it is HVACs are mostly hacks. Three aproaches can be used to lower static with zoning:
1) Controlled leaks ( dampers don't close 100% ) 2) Damp zones ( like two story entrances ) 3) barametric damper bypass
How? did heat exchanger split? If so why didn't $90 guy see the crack?
Or do they just want to sell you a new 6k system?
How old was the system anyway?
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