J's profile - activity

Great explanation. I'm always cautious with sizing so it is good to see a clear comparison.

Good. That a reasonable question and I can tell you that I'd be willing to promise 30% energy savings with less than 6 year simple payback in my market for optimizing a code-minimum building design. I'd target 40% in the model but would never promise more than 30%.

This depends completely on what you mean by 'optimized'. In my experience with mid-tier buildings in New Zealand the main impact of modeling the building is developers can actually get meaningful answers to questions like how much will I save if I change the glazing from X to Y or add in exhaust ventilation heat recovery. Again in my experience on the few projects I've worked on we hit 30%+ minimum savings over the initial business as usual plan. On the last project I did the results agreed with the model (which showed about 40% savings) too closely to be realistic. Had the interesting issue of explaining to the developer that the close agreement was just luck.

In New Zealand EECA (our local version of DOE) has started assisting with funding of the energy model but the real driver is making the accountants BELIEVE the results and then they are willing to invest in the building or increase the control system deadband etc. EECA targets 25% minimum as the cost-effective savings changes that need to be driven by the energy modeling to obtain their funding assistance.

Now if you meant optimizing the building to mean not changing equipment - changing controls / operations / settings than commissioning (perhaps informed with a model if it exists) would be the place to go. One of my associates claimed he just saved 50% - stupid building was running full tilt nearly 24/7! On one of the flash eco-buildings I was working on the commissioning agent found out the optimum start was not good and likely saved 5% in one winter evening.

Yes it is a Climaveneta unit but I won't be selecting the equipment and may end up modeling several suppliers units. The CentralHeatPumpSystem and PlantComponent:UserDefined are the options I'd looked at but you are right in that I'm intimidated by the UserDefined. I hadn't thought of using a fluidcooler on the condenser loop have to sketch that idea out and see how it might work. Thanks for the idea.