[Equest-users] Unmet hours in residential building

[Michael Campbell]

Hi Joe,

I have and the SV-A report is giving me zero heating capacity for the
bathroom zones.

On Wed, Oct 28, 2015 at 9:14 PM, Joe Huang <yjhuang at whiteboxtechnologies.com
> wrote:

> Mike,
>
> Allow me to jump in here a bit.  Have you looked at the SV-A report to see
> what DOE-2.2 has sized for the HVAC system, particularly the supply-cfm and
> heating/cooling capacities for the bathroom ?
>
> Joe
>
> Joe Huang
> White Box Technologies, Inc.
> 346 Rheem Blvd., Suite 205A
> Moraga CA 94556yjhuang at whiteboxtechnologies.comhttp://weather.whiteboxtechnologies.com for simulation-ready weather data
> (o) (925)388-0265
> (c) (510)928-2683
> "building energy simulations at your fingertips"
>
> On 10/28/2015 1:17 PM, Michael Campbell wrote:
>
> I've tried different values for the degree day multipliers, into the
> hundreds.  I'm trying out different scenarios now to see what works, but
> I'm still getting unmet heating hours in the bathroom.
>
> On Wed, Oct 28, 2015 at 3:57 PM, Julien Marrec <julien.marrec at gmail.com>
> wrote:
>
>> Mike,
>>
>> You have set a zonal exhaust with make up air defined as infiltration?
>> And your space linked to the thermal zone has an infiltration defined as
>> ACH with a higher value for design days? How much higher?
>> Your HVAC is autosized for the zone?
>> Do you still have unmet hours for the bathroom?
>>
>> If this is not doing anything, your HVAC system might be already
>> autosized to a greater value due to another parameter such as sizing factor
>> so that the added infiltration does nothing.
>> Or maybe your zonal fan doesn't actually run? Try and request some hourly
>> variables to understand what is going on.
>>
>> Julien
>> Envoyé de mon iPhone
>>
>> Le 28 oct. 2015 à 20:27, Michael Campbell < <mcamp1206 at gmail.com>
>> mcamp1206 at gmail.com> a écrit :
>>
>> Julien,
>>
>> Regarding the infiltration method... I am currently trying to do this
>> with a small bathroom with 50cfm exhaust.  This is a core zone.  Adjusting
>> the design day values as described in the write-up does not appear to be
>> doing anything.  Any thoughts?
>>
>> Thanks,
>> Mike
>>
>> On Thu, Oct 15, 2015 at 11:45 AM, Julien Marrec <
>> <julien.marrec at gmail.com>julien.marrec at gmail.com> wrote:
>>
>>> Michael,
>>>
>>> First, you're under 300 hours so indeed it's a minor problem.
>>>
>>> I've only looked at your model very briefly but:
>>>
>>>    - HW loop operation is set to "SNAP" at OA of 60°F. This is causing
>>>    some minor underheating in shoulder season.
>>>
>>>
>>>    - You have local exhaust fan with makeup = infiltration. Basically
>>>    equest ignores this added infiltration during the sizing, so you have to
>>>    trick it to take it into account by having a different schedule for sizing
>>>    (heating AND cooling design days). I've put together my findings on the
>>>    subject on Unmet Hours here
>>>    <https://unmethours.com/question/3102/how-do-you-model-exhaust-fans-in-equest/>
>>>    in some kind of tutorial that I hope is helpful.
>>>
>>>
>>> Do the above and your unmet hours disappear.
>>>
>>>
>>> Additionally:
>>>
>>>    - Throttle range of 0.3°R seems pretty aggressive to me.
>>>    - when you use baseboards and want to oversize, use the system's
>>>    sizing ratio
>>>
>>>
>>> Hope this helps,
>>> Julien
>>>
>>>
>>> --
>>> Julien Marrec, EBCP, BPI MFBA
>>> Energy&Sustainability Engineer
>>> T: +33 6 95 14 42 13 <%2B33%206%2095%2014%2042%2013>
>>>
>>> LinkedIn (en) : <http://www.linkedin.com/in/julienmarrec>
>>> www.linkedin.com/in/julienmarrec
>>> LinkedIn (fr) : <http://www.linkedin.com/in/julienmarrec/fr>
>>> www.linkedin.com/in/julienmarrec/fr
>>>
>>> 2015-10-15 16:30 GMT+02:00 Michael Campbell < <mcamp1206 at gmail.com>
>>> mcamp1206 at gmail.com>:
>>>
>>>> I mistakenly attached the PRD file instead of PD2.  Correct files are
>>>> attached.
>>>>
>>>> On Thu, Oct 15, 2015 at 10:16 AM, Michael Campbell <
>>>> <mcamp1206 at gmail.com>mcamp1206 at gmail.com> wrote:
>>>>
>>>>> Hello,
>>>>>
>>>>> I'm having what appears to be a minor issue with unmet hours in a
>>>>> model that I've inherited.  My INP and PD2 files are attached.  I've tried
>>>>> adjusting the cool sizing ratio and and adjusted infiltration rates and
>>>>> equipment loads with no real effects.  Anybody have any ideas?
>>>>>
>>>>> Thanks,
>>>>> Mike Campbell
>>>>>
>>>>
>>>>
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>>>
>>
>
>
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