Looks like some valid questions here so I've asked one of our UK Compliance experts to comment further from their own experiences. Will post back here any guidance we have on this.
Phil
ApacheHVAC in Compliance Simulations
Re: ApacheHVAC in Compliance Simulations
IES Worldwide Technical Support
Re: ApacheHVAC in Compliance Simulations
after some discussion in here, some notes from one of our Support consultants:
You are right in your assumption that every set point, vent rate etc. would have to be set up in accordance with those dictated by the NCM. This is a task that only the most experienced of users should attempt to undertake, primarily due to the enormous number of profiles that need to be correctly allocated to the ApHVAC network.
I have heard rumours of users attempting this feat, however I have never seen it in practice. I personally would not advise using ApHVAC for L2 studies, for the following reason.
Under the old regs you could benefit greatly by the part load performance modelled in ApHVAC in terms of the Auxiliary Energy. Under the 2010 regs this benefit is negated by the NCM conventions on Auxiliary energy (as you quite rightly point out).
'Is anyone actually using ApHVAC for Compliance Sims?' - a quick survey of the consultants in here reveals that NO 2010 L2 studies using ApHVAC have crossed their paths, and none of them would advise attempting it.
In short, there may be benefits gained by using Apache HVAC in terms of the part-load performance of thermal systems, but I would say these benefits would be minimal and not worth the time and effort required to properly set up an ApHVAC network under the NCM requirements.
You are right in your assumption that every set point, vent rate etc. would have to be set up in accordance with those dictated by the NCM. This is a task that only the most experienced of users should attempt to undertake, primarily due to the enormous number of profiles that need to be correctly allocated to the ApHVAC network.
I have heard rumours of users attempting this feat, however I have never seen it in practice. I personally would not advise using ApHVAC for L2 studies, for the following reason.
Under the old regs you could benefit greatly by the part load performance modelled in ApHVAC in terms of the Auxiliary Energy. Under the 2010 regs this benefit is negated by the NCM conventions on Auxiliary energy (as you quite rightly point out).
'Is anyone actually using ApHVAC for Compliance Sims?' - a quick survey of the consultants in here reveals that NO 2010 L2 studies using ApHVAC have crossed their paths, and none of them would advise attempting it.
In short, there may be benefits gained by using Apache HVAC in terms of the part-load performance of thermal systems, but I would say these benefits would be minimal and not worth the time and effort required to properly set up an ApHVAC network under the NCM requirements.
IES Worldwide Technical Support
Re: ApacheHVAC in Compliance Simulations
Yeah, from reading these comments it's the kind of thing I'd usually suggest the option should be removed form the software but since it is technically possible and it's functionality we've offered in the past then I think we need to keep it and hope that users are educated enough to use it properly.
It was a very good question to raise though so thanks.
Phil
It was a very good question to raise though so thanks.
Phil
IES Worldwide Technical Support
Re: ApacheHVAC in Compliance Simulations
Parky John,
Apologies again for the delay in this one but as I've mentioned in another post I've not been "doing IES" for quite some time and I'm back only for a short period... like the ribwich!
I think this is for the benefit of others who might see this other than IES Pimps like ourselves but I think I'd make the simple note:
DO NOT USE APACHE-HVAC for Part L (or the other regs... Scotland, Ireland take a bow).
There are so many other simplifications and standard libraries applied that the extra effort required to define a detailed HVAC network for what is only ever going to be a mild effect is simply not worth the effort.
I saw the "proxy for HVAC" ting come in a while ago and wondered why bother - must be some techie that thought it might crop uip. Obviously someone who's not had to get a job out to a customer in a shorter time-frame than the competition when the fee is required to pay for the rent...
Can anyone tell I'm upset at working this late on a Friday yet. Argument would be "if you are working why are you posting on here" to which I would reply "use the IES a little longer and you'll find out" ... suncast I hate you! Is it 2011? I got a mortgage quicker than this b***ard takes to tell me the sun is hitting a south facing wall at 4pm in May.
Zap.
Apologies again for the delay in this one but as I've mentioned in another post I've not been "doing IES" for quite some time and I'm back only for a short period... like the ribwich!
I think this is for the benefit of others who might see this other than IES Pimps like ourselves but I think I'd make the simple note:
DO NOT USE APACHE-HVAC for Part L (or the other regs... Scotland, Ireland take a bow).
There are so many other simplifications and standard libraries applied that the extra effort required to define a detailed HVAC network for what is only ever going to be a mild effect is simply not worth the effort.
I saw the "proxy for HVAC" ting come in a while ago and wondered why bother - must be some techie that thought it might crop uip. Obviously someone who's not had to get a job out to a customer in a shorter time-frame than the competition when the fee is required to pay for the rent...
Can anyone tell I'm upset at working this late on a Friday yet. Argument would be "if you are working why are you posting on here" to which I would reply "use the IES a little longer and you'll find out" ... suncast I hate you! Is it 2011? I got a mortgage quicker than this b***ard takes to tell me the sun is hitting a south facing wall at 4pm in May.
Zap.