LEED project boundary lines that “slice” through party walls must not pass through any MEP service infrastructure. Exceptions include buildings served by a common or shared chiller plant or heating water, or steam supply pipes (i.e., not air ducts), and only if the thermal energy serving the structure to be separated is sub-metered. (p. 42 of “LEED 2009 MPR - SUPPLEMENTAL GUIDANCE”).
The building that we want to certificate is being renovated and it is divided in two parts, one (offices) is going to be certificated LEED, the other one (factory) isn’t, although both are being altered. Would the use of a reversible heat pump that transfers heat from a building to the other one be possible? The goal is the conditioning of the offices, i.e. the heat pump heats them during winter and cools them during summer. An advantage is that in the industrial building there is a large thermal inertia.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5909 thumbs up
March 1, 2013 - 1:54 pm
If the flow is only one way - factory to office - then is seems like you could isolate it and associate it with the office only. Hard to say for sure without knowing more about the systems and buildings.
Francesco Passerini
engineer90 thumbs up
March 4, 2013 - 9:55 am
Thank you, Marcus
When you write "flow" do you mean "heat flow"? It isn't only one way, because it is supplied to offices during winter season and it is removed from offices during summer season. The reversible heat pump exchanges heat directly with the air of the factory and it exchanges heat with the offices thorough a water loop. Then the water loop serves radiant floors and the water coils in the AHUs of the offices. Regards
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5909 thumbs up
March 4, 2013 - 9:35 am
We have the same understanding of flow. So it sounds like an air to water heat pump but instead of the condensing unit being located outside it is inside the factory. If that is correct the question becomes - can you simulate the affect on the heat pumps of this location instead of the outside?
Francesco Passerini
engineer90 thumbs up
March 4, 2013 - 10:08 am
It is correct, Marcus. Thank you. Now I have to understand how I could do with the simulation software.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5909 thumbs up
March 4, 2013 - 10:57 am
As usual it depends on the software. The condensing unit will operate at a narrower range than if it was outside. This could possibly be simulated with a custom curve and/or some post-processing of the modeling results examining the hourly data. Sounds like a work-around is needed. I would consult the software vendor and discussion groups for the particular software for ideas on how to simulate this situation.
Francesco Passerini
engineer90 thumbs up
March 4, 2013 - 11:50 am
I have discovered that in EnergyPlus among the inputs of the object WaterHeater:HeatPump there is "Inlet Air Temperature Schedule Name". I think I'm going to use as schedule the setpoint temperatures of the factory.
Thank you for the help, Marcus. I feared that such a system was not compatible with the concept of "party wall". Best Regards
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5909 thumbs up
March 4, 2013 - 11:43 am
I think you can make the case but this is a grey area. For me since there is not a direct exchange of air or water crossing the boundary I think it is cleaner and more straight forward. The conditioning systems are really separate it sounds like to me even though the condensing unit will potentially impact energy use in the factory as well.