Discussion on energy-subcommittee

[meteyer]

J Boldt - Everyone – 90.1 passed several items that could affect
healthcare and that you should review in a month or so when they are
issued for public review. The one that will affect us in HVAC the most
is a proposal to allow the reheat exception only if the supply air is
reheated no more than 15F above room temperature. This would basically
mean that if you can’t heat a perimeter room with 30% of the box peak
flow rate using 90F air; then you must use a fan-powered box, add
local heat (e.g. radiant panel), or get your architect to design a
better envelope.



I believe that addendum AS was affirmed and will enter 90.1 also,
which would prohibit most constant volume healthcare designs.

[west...@upstate.edu]

Operating in a cold climate, I'm not sure I agree with this. A
patient in an ICU room with high air flow (minimum 12 ac/hr) isn't
going to comfortably tolerate a 75 degree discharge temperature
whether there is a radiant panel or not, at that airflow and
temperature the patient will complain of "drafts". Fan powered boxes
would probably end up in the patient rooms which makes maintaining
them difficult. How do we zone these systems so that a primary supply
temperature is higher than 60 degrees. I'm not sure it's all that
practical unless we the patient care exemption is maintained.

[Jeff Boldt]

If the ICU were kept at 75F, the maximum discharge temperature from
the diffuser would be 90F, which still will require changes in the
designs used by many firms for some zones.

On Jun 24, 4:35 pm, "westb...@upstate.edu" <westb...@upstate.edu>
wrote:

> > which would prohibit most constant volume healthcare designs.- Hide quoted text -
>
> - Show quoted text -

[Ron Westbrook]

Jeff: I guess I'm confused, is the maximum 15 degrees above room
temperature, or supply air temperature? I interpreted it as the discharge
set point of the AHU. If it is room setpoint, as you reference, it is less
of a concern.

Thanks
Ron

>>> Jeff Boldt <solt...@charter.net> 6/29/2009 10:05 AM >>>

If the ICU were kept at 75F, the maximum discharge temperature from
the diffuser would be 90F, which still will require changes in the
designs used by many firms for some zones.

On Jun 24, 4:35 pm, "westb...@upstate.edu" <westb...@upstate.edu>
wrote:
> Operating in a cold climate, I'm not sure I agree with this. A
> patient in an ICU room with high air flow (minimum 12 ac/hr) isn't
> going to comfortably tolerate a 75 degree discharge temperature
> whether there is a radiant panel or not, at that airflow and
> temperature the patient will complain of "drafts". Fan powered boxes
> would probably end up in the patient rooms which makes maintaining
> them difficult. How do we zone these systems so that a primary supply
> temperature is higher than 60 degrees. I'm not sure it's all that
> practical unless we the patient care exemption is maintained.
>
> On Jun 24, 5:14 pm, meteyer <mmete...@erdman.com> wrote:
>
>
>

> > J Boldt - Everyone * 90.1 passed several items that could affect

> > healthcare and that you should review in a month or so when they are
> > issued for public review. The one that will affect us in HVAC the most
> > is a proposal to allow the reheat exception only if the supply air is
> > reheated no more than 15F above room temperature. This would basically

> > mean that if you can*t heat a perimeter room with 30% of the box

[Jeff Boldt]

It's 15F above SPACE temperature, but if there is no code or accreditation
mandated minimum ACH the flow rate must fall into one of the other 90.1
reheat exceptions; of which the 30% of peak cooling flow rate is the only
viable one. So you get ~90F air at 30% of peak cooling flow rate.