Dear all:-
Our project have installed with VRF with TFA Unit
Due to TFA unit usage we have significant saving in HVAC because outdoor air supply temperature is very low now we have some doubts in this TFA unit at Energy modeling
Note :- This TFA unit is not interlocked with HVAC system (VRF) & the Fresh air and Dehumidified air ratio is below 30% only
Doubts are
1.How we model these TFA unit Either Identically or for proposed case only
2.Can we take a advantage of TFA unit in proposed case alone or Both cases (can we take fresh air supply temperature as same as ambient outdoor dry bulb temperature in Baseline case)
3.Additionally TFA unit is located in Rooftop only can we exclude the energy cost of those TFA unit in HVAC cost because these kind of Loads are considered as process load and modeled Identically in LEED NC.
SAMY Chamy
EnginneerT&T Green
12 thumbs up
September 12, 2016 - 12:21 am
Dear All:-
Awaiting for your reply
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5867 thumbs up
September 12, 2016 - 9:50 am
1. Sounds like a dedicated outside air system. This only gets modeled in the proposed and not in the baseline.
2. Yes you can.
3. No. The proposed must be modeled as designed.