HVAC Ducts Reality Check: Are Ductwork Systems Dumb or Essential?

Just wanted to spell out why central duct systems are a central part of ANY home design. Yes, ductless mini split heat pumps are awesome. Yes, radiant flooring is comfy. Yes, lots of people use decentralized HVAC strategies around the world and are happy with them (or at least they don't know what they're missing).
Duct systems can be used to filter and deliver healthy air to every room in the house- humidified/dehumidified, diluted with outdoor air, and pressure relieved for kitchen exhaust.
Learn more about designing ventilation and HVAC in general at: BuildingPerformanceWorkshop.com
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[@JahariAluvis]

Thank you for this very helpful video. We live in an area where most of the houses were built from 1890 to 1940 and it is often difficult to retrofit hvac. Heat pumps are very popular, but ours has old duct work from the '70s that I need to update (also asbestos). Dust is definitely a big problem and it was encouraging to see the merits of upgrading the old ductwork and filters rather than going with another solution.

[@rempe772]

Great content! Professional, clear and to the point! So glad to have found this video before deciding what to use for heating/cooling my attic as it turns into a living space!!

[@thewakersci]

Great video! One thing I personally enjoy exposed ductwork because I know if it leaks it just leaks into the conditioned space so no big deal, also putting it in a plenum can make it less ugly to some (as long as the adjacent wall/ceiling is airtight). 👍

[@chrismaxny4066]

Our home located in the Hudson Valley in NY was built in 1987 with a joke of an HVAC system. The return consisted of two 4 x 10 inch vents for a 1900 sq ft house! The ductwork was fiberboard of some kind. Shortly after we bought the home the oil furnace heat exchanger was found to be cracked and couldn't be repaired. We replaced the furnace and they enlarged the return but only minimally and as we were new home owners had no idea there was still a problem. A few years later we got a heat pump and finally put in a properly sized return system. In the early Spring of 2021 the furnace started leaking heating oil which filled the house with an awful smell requiring us to open every window and door to vent it. Faced with repairing the furnace and replacing the 34 year old oil tank we decided to install Geothermal and avoided a mini split system because of all the hardware and maintenance. It required completely redoing the ductwork (a very big job) and upgrading the electric pane to 200 amp service (lucky this only required replacing the panel). After all is done we have a 5 ton Geothermal System, completely new, properly sized and insulated all metal ductwork and 200 amp electrical service. We are extremely happy with the decision and have also added solar and an electric car. The solar system is big enough to power everything and our last electric bill was -$415 reflecting what we had over paid to the electric company in 2022. Sorry to be so long winded!

[@CJRoe]

We are building a new home and will have a mix of ductless and ducted. The ducted system will return air from all areas for filtration and deliver humidity to the main parts of the open living area, the bedrooms will be ductless. Great video!

[@benjaminallen2370]

Absolutely illuminating. I just had ducted mini splits installed from a top recommended contractor…. pretty good job, though I discovered the return air filter boxes are 20-40% below mfr Fujitsu recommendation- not hard to upsize them so I’ve done 2 of 3 so far with substantial benefit. I always find myself tweaking things after every type of contractor I’ve ever hired :). Also Definitely less household dust that our baseboard oil heat.

[@edlauren9434]

Thank you for this video. I am bouncing into the very same question during last 1-1.5 years and in some projects I am using ductless systems with 2-3-4 evaporators, or a combination of a regular ducted HVAC with a mini-split or two for bonus room/basement/attic… Thank you again for this video. If is very interesting to hear your ideas about the matter.

[@atlengdave]

We are about to install a similar system in our attic. Very helpful video - great job!

[@swilhelm3180]

Your dedication to your craft is admirable. It's obvious you have an analytical mind and it so benefits your viewers here. I am disturbed at how many people seem satisfied in having a living space with no fresh air for months at a time. We do get used to lousy air in the home. And that's a very dangerous adaptation.

[@D8099.]

Wow perfect video. You hit every what if question in my head. I was literally going nuts trying to plan my remodel. I just knew it felt wierd pulling all the ducts out and leaving them out. My house would be DONE by now, If someone had made a video like this 5 years ago 😂

[@BirchwoodBill]

Good video. Just designed the house floor plan doing a manual J and manual D in parallel, so there is room for ductwork. Holistic approach following Healthy Heating guidelines

[@levidobbin5654]

So many houses I've done, they'll rip out all the old electrical, all the old appliances, all the o!d plumbing - but either not change any 70's era ductwork, or expect the new stuff to be the same size, and perform better.

[@jepito29]

My 1950 bungalow had no insulation, aluminum single pane windows and only 1 wall furnace. Putting in multihead ductless for heat/Ac, a muilti branch duct system for an erv, and a separate/simpler ducted system for filtering and Dehum. And a make up air for range hood.

[@AaronHope_Sow]

Thanks for the tough lesson. I was definitely one of the ppl ready to delete ductwork from design especially when I came across a manufacturer that claims their system does radiant cooling. I was SO ready lol

[@theinfernalcraftsman]

Thank you this video will make my life easier when trying to explain to people the issues with going minisplit only and other issues as well. I can just have them watch this.... We will never see minisplits with adequate filtration because it will require a far more powerful blower in the unit which will increase noise and reduce efficiency.

[@Joe-qw6il]

Speaking about ducted systems, I am in the process of redesigning my ducting system for my bedrooms-hvac, all attic installed-- reason is too much pressure in the bedrooms on one side if the house and tool low on the two bedrooms on the other side--the tow bedrooms with the high pressure are directly below the furnace and supply ducts are connected directly off the supply plenum, hence short run, the other side of the house (2 bedrooms) is supplied via a distribution plenum connected via a 30’ plus long 14” flexible duct--and its all made worse in that all ducting and distribution plenum is suspended above insulation so it becomes pretty hot-my plan was to have a new supply plenum distribution box fabricated and place that in the middle of the house, then run equal lengths of flex duct to each of the bedrooms from there--I spoke to a local contractor and he said plenum boxes were old technology and better way to do it would be using all wyes, is this how things are now done? Central California location, up to 105 degrees in summer and down to 30 degrees in winter and everything in between, thanks

[@dammitbobby283]

What I've discovered is that the majority of KZbin videos primarily emphasize the simplicity of installing ductless mini-split systems. In my view, such ductless systems are rarely necessary. Many individuals are unaware that they can purchase a ducted mini-split. Air ducts are exceptionally valuable in numerous scenarios, such as new construction or remodels, as they allow for even air distribution, unlike ductless mini-splits that only offer a single point of airflow.

[@BrianKrahmer]

i will be building several houses over the next few years, and they all have a set of things in common: 1. radiant floor heat. 2. an HRV. 3. a mini-split for minimal A/C. perfect combination and only a little duct work

[@soleadoc]

Very good. We had a very similar problem recently on a custom design.

[@zanedzikonski4234]

Thanks for this, I have central air with a duct system. A roof top unit with no attic other than 2x8 rafters and soffits built to hide ducts. Makes for a very noisy system and I think I also loose a lot of energy in the ducks due to lack of proper insulation Was thinking o doing a few mini splits and some in wall fans to transfer air to other smaller rooms. Thanks for info on filtration, I forgot to account for that. I had idea to get a mini split for main space then use the central air only as needed for when bedrooms are occupied.