Proper Design For Ductless and Ducted HVAC Systems
HVAC School - For Techs, By Techs
Bryan Orr
4.9 • 1K Ratings
🗓️ 25 March 2021
⏱️ 57 minutes
🧾️ Download transcript
Summary
In this podcast episode, Bryan, Chad, John, and Allison discuss proper design for ductless and ducted HVAC systems, especially mini-splits. They also discuss potential future improvements to equipment and duct designs.
Mini-splits are smaller than traditional HVAC units, so they make zoning a bit easier. However, load calculation plays a huge role in equipment selection and zoning because you must get the right number of zones to match the equipment capacity and meet your load requirements.
Proper design is difficult, and a common mistake includes using one piece of equipment to serve the whole house, especially on new constructions. Some designers also don't offer multiple options to the customer, which can be a mistake. Most of the time, we end up downsizing systems, not making them larger. Failing to smooth out turns in the ducts and use proper fittings can also negatively affect airflow and pressure. If you're working on new construction, you'd be best to get an idea of the building design ahead of time and clearly communicate what you need to create a proper duct design.
Going from traditional to mini-split duct design has a bit of a learning curve. It's easy to make mistakes when you aren't prepared to deal with the function of variable capacity in mini-splits. You can avoid making mistakes by learning about the equipment (and duct materials) during the selection process, not after the selection.
Chad, John, Allison, and Bryan also cover:
- Adjusting the structure
- Replacing old equipment with higher-SEER equipment
- Selecting filters and filter grilles
- Static pressure options
- Total length vs. total equivalent length
- Register sizing
- Flex ductwork
- Drop ceilings
- Texas's energy grid and how it relates to potential setbacks
- Replacing furnaces with heat pump systems
- Future micro-split heat pumps
Check out energyvanguard.com and think-little.com.
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Transcript
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| 0:00.0 | The HVAC School Podcast is made possible by these great sponsors. |
| 0:08.8 | Mitsubishi Electric. |
| 0:10.7 | Go to Mitsubishi Comfort.com to find out the full line of products. We often will call them |
| 0:16.2 | duckless product, but frankly, Mitsubishi's making a lot of really great ducked-in mini-splits nowadays. |
| 0:21.3 | Some of them low static, some of the medium |
| 0:23.7 | static, their product line is just enormous. They have a really great grouping of |
| 0:27.3 | products that you can do many different things and many different applications. |
| 0:30.8 | If you haven't taken a look at Mitsubishi in quite a while, go to Mitsub comfort.com and find out more. Stand to your feet unless you're driving and welcome the man who insists on wearing his |
| 0:45.9 | duck knife on his belt even though he hasn't actually cut a sheet of board since 2008. |
| 0:51.1 | Brian Orr. Hey this is the HVAC School Podcast, the podcast that helps you remember some things you might have |
| 0:57.8 | forgotten along the way as well as helps you remember some things you forgot to know in the |
| 1:01.0 | first place. |
| 1:02.0 | And this episode is one that I am very |
| 1:04.2 | excited about. It is about the proper design for ductless and ducted |
| 1:08.4 | HVAC systems and specifically talking about the ducted part of mini splits so systems that we would traditionally call mini splits but they have ducks on them how do you design for that and we have an all-star crew |
| 1:20.6 | Chad Gillespie is the senior manager of performance and construction from |
| 1:24.4 | Mitsubishi Electric Train USA. John Semmelhac, owner of Think Little and |
| 1:28.9 | partner of my good friend Neil Camparetto up in Virginia and Allison Bales the owner of Energy Vanguard which is one of the |
| 1:37.8 | premiere design firms in the US in my never to be humble opinion as well as the author at Energy Vanguard, the blog |
| 1:46.4 | and website, which is some of the best information on home performance in our industry. |
| 1:51.2 | So this is going to be a very broad conversation. Big thanks to |
| 1:55.7 | Mitsubishi Electric Train USA for sponsoring this and making it possible. But here we |
... |
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