#1 By: Richard Snape, December 9th, 2014 06:22
I'm wondering if anyone else has noticed that Queen's building appears to be being heated throughout the night? Also, the smartspaces model / algorithm appears to be saying that gas consumption during the overnight heating is in the "yellow" even though by eye it looks well above the red. An example period is this one. There's something funny about the water model there too, I think - it seems to be shooting off to infinity. Maybe the gas model is doing the same?
Anyway - it just seems like overnight heating is a bad strategy, whatever the model is saying - does anyone have a view on this?
#2 By: Graeme Stuart, December 9th, 2014 07:32
The system doesn't report on overnight heating so I'm not sure what you mean on point 1. The faces are always daily or weekly averages so its averaging the red overnight values with the green daytime values. The values being averaged are percentiles so extreme high and low values are capped to 100 and 0. There may be a better way to aggregate these numbers. Happy to discuss at some point if you have any thoughts on this.
I can't explain the water model. Its likely that it is due to an erroneous model structure and will cause problems on cold Saturday mornings.
#3 By: Richard Snape, December 9th, 2014 09:23
Sorry - my sloppy terminology. I'm characterising this as overnight heating (gas usage in the night). The little summary graph at the bottom is not showing a red stripe in the gas to say that the night was all red, so I'm characterising that as "overnight heating" being reported as "in the yellow". I did wonder if the stripe was just too thin to be resolved, but other examples tend to indicate that any red stripe does appear.
This might be an averaging algorithm detail thing (don't really want to get into that discussion again), but I'm just curious as it seems more like the system isn't putting the "red" status of the gas into the summary for some reason.
#4 By: Graeme Stuart, December 10th, 2014 06:34
The little summary graph shows daily aggregated values, there are 365 values presented. If it were half hourly then you would get a bit of red in it. As its daily, the good offsets the bad.
#5 By: Richard Snape, December 10th, 2014 07:37
Interesting. So, it looks like the new boiler system is so much better in the daytime (i.e. lesser consumption at that external temperature than that predicted by the model), that it compensates for being set such that it is allowed to heat overnight (which conventional wisdom / evidence / the losses due to heat loss rate of any building tells us is bad at all times when setback is allowable for comfort reasons).
#6 By: PWE, December 17th, 2014 08:46
The overnight heating has been triggered by the buildings frost protection settings. This will initiate the heating if external temperatures fall below three degrees. This is to stop any pipes in the building from freezing. We are currently in the process of harmonising fabric protection settings across all buildings and will look to adapt both Queens' and Trinity Houses' settings in recognition of their high thermal mass. We will be heating the building for 24 hours on 04/01/14 so that there is some chance of it being warm when you all return from your break. Have a great xmas!!!
#7 By: Paul Fleming, February 3rd, 2015 06:35
The frost setting on queens building will bring the heating on at night when the outside temperatures are very low - like in the last week. Are we sure the frost protection is set correctly? From the graph of gas consumption in the last week, it looks like the building is heated to the same temperature during the day and night. Is this correct? What is the nighttime temperature setting? Is it possible to reduce the night time temperature setting if it is too high?
#8 By: PWE, February 17th, 2015 09:13
The frost setting point is 12C, to provide fabric protection against condensation. The frost protection kicks in at 3C and cuts out again once the temperatures rise above 5C.
#9 By: Paul Fleming, February 25th, 2015 08:43
Do you think that there are opportunities to optimise the frost protection settings to maintain comfort and building fabric whilst minimising gas consumption?
#10 By: Paul Fleming, February 27th, 2015 11:47
It looks like the heating was on again overnight last night (a cold night). What temperature does the frost protection heat the building to? Its normal day time temperature?
#11 By: PWE, March 10th, 2015 06:59
The fabric protection settings set the internal temperature to 12 degrees in frost protection.