Duct Size L S

[Carmelina Olden]

Also you can buy zehnder components a la cart so you could buy manifolds, tubes and registers and pair them with a less expensive erv and maybe save yourself trouble and probably some bandaids if this your first time with sheet metal.

6" is a bit on the small side for a trunk on that unit on boost especially if your runs are longer. I would step it up to 7". Low loss ducts also reduce the fan power which can add up even on an ECM unit.

ERVs are pretty quiet but not silent. If you have mostly hard pipe, make sure to install a length of flex between the unit and supply ducting or a duct silencer. Without this you can hear the unit go on boost in a bedroom which is annoying.

As a ballpark, you are looking at 4" for a bedroom and 5" for a kitchen pickup. I would use a 5" for the pickup for the most used bathroom, the rest can be 4". Rooms that will rarely be used can even go down to 3" pipe as these only need 10cfm.

In this guide, we will cover the importance of accurate duct sizing, the consequences of incorrect sizing, an overview of typical sizes, and detailed formulas and examples for circular and rectangular ducts.

Additionally, oversized ducts may result in poor air distribution and temperature inconsistencies, whereas undersized ducts can cause increased noise, reduced system efficiency, and even premature system failure.

Common problems associated with incorrect duct sizes include increased noise, higher energy consumption, uneven heating or cooling, excessive wear on system components, and reduced overall HVAC system efficiency and lifespan.

"The software offers precision through detailed result outputs and advanced options for efficient pipe sizing, allowing heating engineers to optimise based on parameters like maximum velocity and pressure drop."

I am trying to create a generic diffuser family and my connector is staying the same size requiring a transition to connect to it. I am trying to make 1 generic 24x24 diffuser where the connector/neck size auto resizes for the duct connected to it. Any ideas?

I need it to link to a Parameter that controls the Duct size, not the Diffuser size right? The diffuser will always be 24x24 (in this case) I need the neck (connector) to auto adjust when a duct is connected to it. I have attached the family below.

Sorry - I misread your initial post. My previous statement was assuming that you wanted a static neck size. So... I don't believe that you can make the Diffuser's Connector auto-adjust to fit the Duct, it will always be the Duct that adjusts to fit the Connector. Connector with other System Classifications (i.e. Fittings) have the behavior of adjusting to the Duct, but the Diffuser's neck size is supposed to be set that Family, most commonly via multiple Types for difference sizes.

... Actually, just playing around with it before posting this message, I found the problem is not that the connector doesn't autosize to fit the duct, it does. It doesn't auto size to fit flex duct for some reason. I did not notice because I was always connecting with flex duct. So, it will not add a transition if I hard duct to the diffuser but it will add a transition if I flex duct to it.

Alright, I see. The size of the Connector will adjust if it is controlled by a Instance Parameter. I'm too used to our being driven by Type Parameters. I also see that the Flex Duct does not force the Connector to re-size, as you said. So have you attempted the process of using standard Duct initially and then using the 'Convert to Flex Duct" tool afterwards?

I'm fairly new to Revit and I'm trying to figure out how to rotate the duct size text. I tried messing with the properties but nothing seems to work so far. Is there a way to add a rotate parameter? If yes how? Once again I'm fairly new to Revit any specific description is highly appreciated, thanks.

You can't rotate the tag directly. I don't care for the only solution I've come up with to get the tag with leader to be horizontal. I select the tag and drag the grip that controls the placement of the bend placement and place it slightly inside the text. I'd really like to find a better way.

out of curiosity, are you trying to tag the duct with a leader and have the text land horizontally? if so, the way we solved that was to uncheck the "Rotate with component" when editing the tag family.

As I mentioned at the beginning, this is how our firm does it. Your firm may be different. Hope this helped someone out there. If for nothing, I now have it documented should I need to recreate that family again. ?

There is a small problem with this parameter if you use it in section it does not switch the values to show the size of the side you are loking at first. ie a 1000300 duct in plan view still annotates as 1000300 in section whereas the sheet metal tag will show correctly in section as 3001000 in section.

Thanks for this tip. Works a treat except for one thing. I cant get rid of the mm text from the size. I have turned off the unit displays within the Project Units for Common and HVAC but the tag displays 1000 mmx200 mm! Any help appreciated.

There is an 8" duct feeding a 6x12 register in my kitchen, that I need to relocate. By doing nothing else, will changing the size of the register to say a 10x10 or 12x12 provide more air and/or better distribution at all? I am pretty sure I need more "washing" of the exterior windows/doors in the area, so I am relocating the register to the center of the room (and will get a 4-way type as well), but I also wondered if going any bigger would help any too. And if so, what would be the biggest size?

Given a circular 8" duct you are dealing with an airflow area of about 50 sq/in. You currently have 72 sq/in opening. I haven't seen a picture of your register - some are not as open as others so it is hard for me to know for sure but... with 72 sq/in opening the air would just dribble out.

This is fine for a floor vent that is unobstructed by walls and furniture but usually not what you are going for. You are usually looking to push the air out a few feet out into the room. A smaller register does this. Also somewhat closing a register does this - however this could push air at unadvantageous angles and you don't want air hitting walls and furniture.

Most registers I size are about the same sq/in's as the duct or a little less. I am looking for the air to be pushed out hard so that it creates airflow in the room. Big rooms with oversized registers can have hot spots away from the register. Now the downside of going to small with your register is that it is too loud. Unless you are severely undersizing your register, the noise is really the only issue.

So a bigger register will not help cool or heat your room better. Putting the register in a better location and making sure the air is shooting out in an efficient manner and at an efficient angle is key.

Do your own research, it's pretty simple math. The links provided above by eddo are excellent.
If you buy your duct work and fittings from Oneida they may do the design work for you, worth asking if you don't want to do it yourself.

I'm a woodworker, not an air handling person too. But all I did was Google "dust collection duct sizing" to get the answers I shared with you, all in 20 seconds or so. It's something any woodworker could have done. :-) So yeah, "do your own research" was good advice, anyone can do it, even woodworkers.

Well, I'm going to have to spend a chunk of time looking through your links. The last one had some helpful info, but reading SP, CFM, FPM, et al, is like reading Greek to me. How do I know what those data points are for the particular tools I have? Well, like I said, I'll have to read and do some more googling. Again, thanks for the lead.

First, I could not ask Oneida's help in planning when I won't be buying anything from them. Oneida costs are way higher than my non-income woodworking budget at this point. I have a good bit of used 4, 6, and some 8 inch duct from big box stores and purchased from other woodworkers. I'm not disputing Oneida quality, I'm just not sure a 5 ft section of duct is worth about 8 times the cost of new from a big box store. If I was earning a living as a woodworker, I might consider it, but not since I'm retired. Thanks for your links and thinkin'.
Alan

Google Bill Pentz and look at his articles. Pretty clever guy but to boil it all down, the specs on the label are always unreliable. For a small shop and a 3HP collector, I would go with 6" or 8" horizontals with 4" drops and keep your hoses as short as possible. You need more velocity in the drops to lift.

After I retired (from a human service organization, not woodworking related at all) I was recruited by a Woodcraft franchisee to work part time on the floor and part time teaching classes. One of the things I learned is that most woodworkers comprehend very little, if any, about the chemistry of finishes (just tell me the brand I should use), nor the air handling engineering aspects of dust collection. They can make some high end things out of wood, but then they are stuck as to how to finish the piece.

SO, on the other website, I was given the following link with a simple worksheet that will probably get me to within 95 percent of my duct size questions. This link, based on what little I know, will probably be my default answer for anyone in the future asking me about dust collection for the small (1,000 sq ft or less) one (1) person shop.
-dust-collection-needs-by-the-numbers?fbclid=IwAR1ul8ieQjQDfaQXq1Fr1QoOPjQsrAsr-Y-hHNyUQ0YAFSRuktoc6ZK0sBc

After I resigned (from a human help association, not carpentry related by any means) I was selected by a Woodcraft franchisee to work parttime on the floor and parttime educating classes. Something I learned is that most carpenters fathom very little, if any, about the science of completions (simply let me know the brand I ought to utilize), nor the air dealing with designing parts of residue assortment. They can put some top of the line things together with wood, however at that point they are adhered concerning how to complete the piece.

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