IES-VE User Forum

Hi all

I'm looking into achieve a 20% renewables target for a hotel and I'm having some difficulty as the DHW demand/energy usage is quite high.
Initially I would've liked to apply an ASHP on 100% of the DHW, but unfortunately there aren't many on the market that are really designed for DHW 100% production and given that most ASHP's designed for space heating have quite poor efficiencies supplying 100% DHW, I think we might have to split production.

Essentially we'll have the ASHP heat water 10-38 °C and then stand alone gas fired to heat from 38-65°C, I can't seem to find a way to apply this in VE SBEM, is there something I'm missing or is there another method which should be used?

Thanks for your help

Hi,

When running SBEM Compliance you don't have that level of detail on the definition of a hot water system. A few options that I think would be sufficient

- Make the hot water system bivalent and define the two heat sources (and fuels) with your estimation of the breakdown in % load being met
- stick with a single heat source on the dhw system and adjust the efficiency to represent the overall system you have designed.

I'd always suggest you run a query such as this past you accreditation scheme to get their take on your approach within the building regulations

Phil

Hi Phil

Thanks for your reply, I've used the first solution you mentioned and everything looks to be working as it should. I've now specified DHW System in tabBTM as a bivalent system sharing the % load between systems with a different fuel for each.

Thanks for your help

Hi Phil

I've been trying to find a solution to this for a while.
When I try setting the bivalent option i get the message "Please note that VE-SBEM does not yet support bivalent Hot water systems"

Can you say what effect this may or may not have on the output results?

Thanks
Phil