Dampers in Heat Ducts

Recently I have noticed many HVAC installers are not installing dampers at the branch boots anymore. The Ontario Building Code does require a device at boot to control and balance air. The register covers that I checked would only open or close which would not allow homeowner to regulate heat in any particular room.

OBC Part 6 (1) All branch supply ducts for residential systems shall be equipped with volume control dampers at the boot to permit balancing or shall be fitted with a diffuser incorporating an adjustable and lockable volume control device that can be set in a fixed position.

Any thoughts?

Volume dampers are rarely installed anymore. You might see one per floor, but even then they are not utilized like they once were.

I would strongly report that in every new construction application I came across.
This is a practice that came along with flex-duct.
Let them get away with it and soon it will become an accepted practice like Jeff pointed out…

As for re-sale houses, I just make a note of it if the owner finds things uncomfortable in places (it’s a balance-design issue not an equipment issue). Some folks spend lots of money on service calls, only to be told the equipment is running fine (without checking the air delivery design). The builder is responsible for the install, not the owner.

These installers don’t know what a “Ductulator” is, or how to use one any more either.
One supply plenum box on top of the furnace and flex from there…

Are they a requirement or a just a necessary component for a well balanced system?

They don’t put dampers at the boot in full basement houses with the furnace in basement because most people end up finishing their basements and covering the ductwork. The last part you quoted re the diffusers with blade, satisfy code requirements. If they don’t like their diffusers (aka registers), send em to home depot, 1 minute to install 6 bucks to buy. Qualified HVAC contractor not required :slight_smile:

That is a lame reason…

So they can’t get it right before closing up the basement?

They don’t need to be accessible. They need to be there for the system to balance in the first place (even more so when they cut into the upper floor duct for the basement)…

I guess they just wait for Mike Holmes to come buy and fix things up! :wink:

Diffusers (the normal type) do not qualify to code standard.

So explain why this does not meet code requirements “or shall be fitted with a diffuser incorporating an adjustable and lockable volume control device that can be set in a fixed position.”

Sounds like a 6 dollar floor register to me.

A volume damper at the register is not a good idea. They typically whistle and are quickly either fully opened or fully closed.

Thanks for your thoughts. I guess it is like most things, the builder gets to save a little money and the home owner gets screwed. Some things never change :slight_smile: