Julien,
Boiler loop is always on.
Even when I using a nighttemperature of 19°C (instead of turning the heating off) , the difference on mondaymorning is stil 36 % between the boiler peak load and the total heating demand at that moment. (69 vs 94 kW)
A few hours after startup the boiler consumes exactly the same as the heating load of all rooms together.
It's just at startup that the difference is that big.
Met vriendelijke groeten, Geert Bellens Bestbuildingconcept BVBA |Ingenieursbureau voor comfort en energie Zimmerplein 16 | 2500 Lier | Belgium |Tel: +32(0)499.71.98.29 Email: Geert.bellens@xxxxxxxxxxxxxxxxxxxxxx | Web: www.bestbuildingconcept.be
JulienBest,If you let the loop water temperature drop all night, I'm not surprised you'd get quite a large startup load, 60% isn't shocking to me.Geert,How are you controlling your boiler/loop in e+?
Are you turning everything completely off (or dropping the loop setpoint really low) from say 9 PM to 7AM and then at 7AM you want it to be just at temperature?
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Julien Marrec, EBCP, BPI MFBA
Energy&Sustainability Engineer
T: +33 6 95 14 42 13
LinkedIn (en) : www.linkedin.com/in/julienmarrec
LinkedIn (fr) : www.linkedin.com/in/julienmarrec/fr
2015-04-20 8:20 GMT+02:00 geert.bellens@xxxxxxxxxxxxxxxxxxxxxx [EnergyPlus_Support] <EnergyPlus_Support@xxxxxxxxxxxxxxx>:
I've done a designbuilder simulation of an office building with fan coil units heating and cooling every room.
In Designbuilder you quickly get the total system heating load (the sum of all rooms) and the Boiler total capacity for heating.
I work with efficiency 100% for the boiler, so normally the heating load of all the rooms, must be the total capacity for the boiler.
In this model, the boiler needs 60 % more capacity ( at 7 AM on the coldest morning in the year) then the sum of the heating load of all the rooms. Later the day, the two are loads are almost equally, so it's just at startup in the morning.
According to the DB support this could be the difference between the inertia of water (fan coils) and gas (boiler).
I've never had such a difference. Is this normal?
What will I communicate to the client as Heating capacity for the boiler? The sum of all the rooms ? Or the boiler capacity as calculated ? (which is a lot higher than the sum of all the rooms)
Geert
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Posted by: Geert Bellens <geert.bellens@xxxxxxxxxxxxxxxxxxxxxx>
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