50% Energy Savings Design for Medium Office Buildings - free resource

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Section 4.4.1 ? I don?t feel there?s enough emphasis on extra zone equipment
here. Most DOAS systems will require something like fan coils (European fan
coils!) or DX terminal units to meet the full heating and cooling
requirements.

In Section 4.4.2:

Radiant system design and application are still in development in the United
States, while they are

more widely adopted in Europe. Unlike VAV systems, there is no well
established radiant system design.

Building surfaces used in a radiant system can be floors, ceilings, and
walls, though the first two are most

commonly applied. *And chilled beams ? maybe a bit complicated to model,
especially active beams*

Different radiant surfaces have different heating and cooling capacities. A
radiant

floor system has a larger heating capacity than its cooling capacity because
radiant floor heating has a

larger heat exchange coefficient between the floor and the space than
radiant floor cooling. According to

Babiak et al. (2009), a radiant floor system normally has a maximum heating
capacity of about 100 W/ft?

(1075 W/m2) and a maximum cooling capacity of about 40 W/ ft? (430 W/m2).
*Er..., how many watts per m2?*

In areas exposed to direct sunlight, the radiant cooling capacity can
increase up to 100 W/ ft? (1075 W/m2). However, floor carpets

may reduce the heating and cooling capacity by as much as 50%. In contrast
to a radiant floor system, a

radiant ceiling has a maximum heating capacity of about 40 W/ ft? (430 W/m2)
and a maximum heating

capacity of about 100 W/ ft? (1075 W/m2) (Babiak et al. 2009). *a maximum
_heating_ capacity of 430 W/m2 and a maximum _heating_ capacity of 1075
W/m2, which one shall I choose :$*

*suspended timber floors can be heated but offer lower W/m2 than concrete/
screed systems*

*profiled concrete soffits can offer further cooling advantages*

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Thank you Bill for posting our recent publication on 50% TSD for Medium Office. This report has been updated with very minor editorial changes. The most recent version is available for free download at the following link:

http://www.pnl.gov/main/publications/external/technical_reports/PNNL-19044.pdf

Regarding Chris comments on DOAS, I agree, DOAS has to work with other HVAC equipment to provide full heating and cooling requirement. So the system we evaluated in the report is DOAS with radiant systems.

Thanks,

Bing Liu P.E., CEM, LEED AP

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