GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

Ducted Heat Pump OR Multizone Mini Split

SamSam1| Posted inGeneral Questionson

ADU Total Area — 1200 sqft (Plan Attached)

Rooms — 6 (avg 90 – 100 sqft each), Kitchen, bathrooms

Ceiling height — 8′

Multi-zone ductless OR Ducted heat pump?

File format

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.

Replies

  1. Steve Knapp CZ 3A Georgia||#1

    Sam,

    Ideally, you would use an accurate Manual J to determine the load. If it's an open floor plan, a single mini split is probably sufficient. If it's chopped up or you expect occupants to keep the doors closed, a ducted mini split would probably deliver better comfort.

    To learn more about who should calculate your Manual J, see//m.etiketa4.com/article/who-can-perform-my-load-calculations.

  2. Paul Wiedefeld||#2

    Manual J then ducted.

  3. SamSam1||#3

    Thank you for your reply. Please help me with this -- My T24 guy says that for I don't need to do Manual J for such a small project (ADU 1200 sqft) as mine. I have attached the plans again, please provide an honest feedback.

    File format
    1. Paul Wiedefeld||#5

      It’s a small investment of time and/or money on an expensive piece of equipment that controls comfort on a brand new building. The size of the building isn’t really relevant here. There are only so many sizes of equipment at your probable load, so it could be guess-estimated, but a half hour seems easy enough. By going with ducted instead of multi-split, you’ve probably saved the cost of dozens of manual Js.

  4. Leon_G||#4

    For what it's worth, I hired an HVAC consultant to help design our HVAC system, a portion of which had a separate 600 sq ft ADU. For that area, he recommended a single zone ducted mini split (PEAD). The ducting is to ensure that air gets to all the areas of the ADU (bedroom, living, and bath).

    I think the general preference is for a ducted unit serving multiple areas rather than separate heads in every room, since in most cases the latter will lead to oversizing, not to mention the added cost of all the equipment.

    But as others said, you need to have some load calculations to properly size the equipment, even if it may not be required by T24.

Log in or create an account to post an answer.

Community

Recent Questions and Replies

  • |
  • |
  • |
  • |