[Equest-users] How to Claim Credits for Natural Ventilation in Multifamily High Rise Residential?

[Ömer Moltay]

Dear Joshua,

Thanks for the info. Does this mean that it is not possible to claim 
credits for natural ventilation?

When you say natural ventilation should be accounted for 24/7, are you 
suggesting that both the baseline and proposed cases need to have 
continous infiltration that corresponds to the natural ventilation 
(although this is not realistic since residential units are never 
ventilated 24/7 by operable windows). What about the cooling effects of 
this ventilation? Can eQuest model heat loss and gain due to natural 
ventilation? Will this be taken into account during simulation so that 
mechanical cooling is reduced in both baseline and proposed cases 
because there is natural ventilation (and also I presume there will be a 
substantial increase in heating energy if the spaces are naturally 
ventilated 24/7 in winter)?

I would appreciate some more guidance on this.

Thank you very much,

Omer Moltay
Mimta

1/17/2012 7:58 PM, Joshua Chapman yazmış:
> Omer,
>
> First, your method for ventilation needs to be the same in the baseline and
> proposed cases.  You will need to provide documentation&  calculations that
> shows each space within the dwellings complies with Natural Ventilation
> requirements.  In Equest, the best way to account for NV is to adjust your
> infiltration.  Change the internal loads to account for 0.35 Air Changes per
> hour for each NV space, in the baseline and proposed.  LEED reviewers are
> particular that natural ventilation is accounted for 24/7.  If your HVAC fan
> runs continuously this isn't a problem, but most residential systems are
> intermittent and modeling natural ventilation as infiltration is the
> solution.
>
> Thanks,
>
> Joshua W. Chapman, P.E., LEED AP
> Scot Engineering Properties Inc.
>
>
> -----Original Message-----
> From: Ömer Moltay [mailto:omoltay at mimtarch.com]
> Sent: Thursday, January 12, 2012 5:25 PM
> To: equest-users at lists.onebuilding.org
> Subject: [Equest-users] How to Claim Credits for Natural Ventilation in
> Multifamily High Rise Residential?
>
> Dear All,
>
> What is the methodology for LEED projects to claim credits (if
> possible?) for natural ventilation in dwelling units? In the building I am
> working on, only openable windows are used for natural ventilation, there is
> no engineered system. Cooling / heating will be provided by VRF units. Can
> one make an assumption that occupied spaces will be ventilated by natural
> means during the times they are occupied in the proposed case, while for the
> baseline case mechanical ventilation will apply?
>
> Thank you,
>
> Omer Moltay
> Mimta
>
>