Dear all,

Our MEP Engineer wants to implement a dual recooling system/the hybrid recooler of the series KAVH. For our building type and the location in Germany with strong temperature fluctuations between summer and winter the system seems to be the most water-saving solution to remove the heat because the technology conserves all the makeup water which usually gets used for controlling microbes, corrosion, and scale in the condenser water system.

In the largest part of the year the recooling system runs like a dry cooler. Only with high outside air temperatures during the summer (switchpoint/startpoint spraying: 26.5 degrees Celsius) the heat exchanger surface will be sprayed. Purest osmosis water will be sprayed on the lamellas and evaporates on the heat exchanger. The evaporization energy cools the lamellas and the fluid in the heat exchanger.

Depending on the load of the device and the condition of the ambient air the spray water amount is continuously automatically optimized by an integrated control system so that the water evaporates almost completely. There is no circulation and no excess water and the usual water treatment with corrosion prevention, hardness stabilization and biocides is no longer necessary.

We do have a really water-saving system, but how can we get full points for this credit?
Strictly speaking the alternative compliance path is not applicable for our case because the system does (seasonal) use latent heat of the evaporative cooling of water in an indirectly way.

Can a special circumstances description and a comparison of the water demand between our system and a comparable cooling tower system with circulation be an accepted way to earn full score?

Or can spraying just recycled nonportable water (rainwater) be an option?

What do you think?
Many thanks in advance for your help.

For determing the openable wall area (which has to be a minimum of 4% of the net occupiable floor area) should WOCDs (Window Opening Control Devices) be considered? Please explain how to determing the openable wall area when using windows with WOCDs.

Thanks Andreas.

I am somewhat confused comparing the requirements of C&S and New Construction. In C&S requirements there is no statement about 10% of energy end use; to me that means advanced meters only for energy sources at site border. Is that correct?
For tenants only meters are required, not "advanced" meters. That means to me the requirements like 1 hour interval etc. do not apply; tenant meters could as well have 1 year intervals. Is that correct?
For both base building and tenants it would not be necessary to determine the 10% energy end uses; but that step is included in step-by-step guidance, also in the online access.
If this is true I think there is no way to calculate base building systems' energy use, as there is whole building data in 1 hour intervals and tenant data (that would be deducted to obtain base building data) in other intervals.
Can someone shed some light on this? If I understand it correctly the credit is much easier for C&S.

Maybe I am overly cautious, but I would like to clarify the following. The Ref.Guide states "base building-level" energy meters.
Does this mean the meters should only measure common areas and systems that are under direct control of the owner? Meaning, receptacles, lights etc. in tenant areas must be excluded? Or can just the main meter be used, which includes tenant consumption as well?
If tenants need to be excluded I assume it is allowable to deduct tenant meter readings from the main meter, correct?

Does anyone know if there are definitions for the different irrigation types? Especially the differences between the two drip types would be of interested.
Thanks, Jens

There are a few AHUs in the project for which I work.
One AHU supplies less than 20% of the non-densely-occupied rooms with its air volume flow, but still has outdoor airflow measurement devices. Three AHUs supply more than 20% of the non-densely-occupied rooms with its air volume flow. This is why outdoor airflow measurement devices are installed in the system.
The problem I have is, that five AHUs supply 100% of the non-densely-occupied rooms with their air volume flow and have no outdoor airflow measurement devices installed. But they only supply air to sanitation facilities (Restrooms, Janitor) and service facilities (Electrical, Technical, COMM).
Do we also need outdoor airflow measurement devices for these rooms respectively for AHUs which supply these rooms?

I am not quite sure on the wording regarding natural ventilation and the Europe ACP.
The online Ref.Guide states
"Projects in Europe may use Arbeitsstaettenrichtlinie ASR 5 as a local equivalent to ASHRAE Standard 62.1-2010, natural ventilation procedure."
The requirements regarding natural ventilation call (besides others) to meet the requirements of ASHRAE 62.1 section 4 or a local equivalent. As the ASR 5 is a replacement for section 6.4 in ASHRAE 62.1, does this mean it is replacing section 4 as well?

Dear all,
I have a question according to meet the composite sound transmission class (STCC) ratings listed in Table 1:
Do we have to meet the STC rating for the combination 'office - hallway' for areas with small office rooms in an open-office plan within a single rental area? Or is 'office - hallway' just the combination were an office room is adjacent to a public corridor outside of the open-office plan / rental area?
Many thanks in advance for your help.

Dear Sir or Madam,
Smoking must be prohibited within 25 feet of building entries, outdoor air intakes, and operable windows. A designated smoking area must be located at least 25 feet away from building openings.
We are working on a NC office building with no operable windows in the ground and first floor. Operable windows are only planned for floor 02-06. Does smoking must be prohibited within 25 feet of the building in areas with no entries and no outdoor air intakes?
Many thanks in advance for your help.

Dear all,
can anyone explain "satisfaction of the authority"?
Under German law the property owner is obligated to remediate all contaminations. At the end of the soil remediation process the owner must typically provide evidence that all contaminations have been removed and that the soil will permanently not cause any damage to or be of considerable disadvantage for the site. Is this evidence sufficient? Typically, there is no confirmation of the "satisfaction" of the authority.
Many thanks in advance for your help.