
Supermarket Model and Performance Report

Introduction

A model of a big-box supermarket was created in ESP-r which
includes a sales area, refrigerated sales area, low and high
temperature chilled cabinets, support area (shipping and 
receiving, cold room, transient storage), office space, staff
room, cafe and an entrance foyer. The overall floor area is
10440 m2 of which ~7000 m2 is public shopping space.

The layout of the supermarket is shown in Figure 1. The main
sales areas are double height as is the shipping and receiving
area. The foyer has a sloped roof and is bounded by the Cafe
and news keosk with office and staff space in the first level.
A summary of the rooms is shown in Table 1.

Figure 1 overall view of the supermarket model.

Table 1 summary of rooms.
ID Zone         Volume|          Surface
   Name         m^3   | No. Opaque  Transp  ~Floor
 1 Sales       24531.5  49  9995.4   718.5  3774.0  
   Sales describes a double height dry sales area.
 2 Refrig       9944.2  21  3984.6  1034.0  1776.0  
   Refrig describes a double height area surrounding chilled cabinets
 3 Foyer        2052.0  17  1111.4   313.1   486.0  
   Foyer describes a sloped roof transition space into Sales
 4 Office1       912.0   7   809.0    48.0   304.0  
   Office1 describes a newstand and anciliary space adjacent to foyer & sales
 5 Cafe          912.0   7   809.0    48.0   304.0  
   Cafe describes an eating area adjacent to the foyer at ground level
 6 Office3       912.0   9   809.0    48.0   304.0  
   Office3 describes a 1st level general office space
 7 passage       270.0   7   357.0    54.0    90.0  
   passage connects office and staff room across the foyer at the 1st level
 8 Staff_traing  912.0   9   809.0    48.0   304.0  
   Staff describes a room for staff changing & meetings.
 9 Store1       1938.0   7  1727.0    30.0  1350.0  
   Store1 describes a ground level sorting area for dry goods
10 Store2       3534.1  14  2728.0    30.0   950.0  
   Store2 describes a double height shipping & receiving area
11 Cabinet_hi    800.0  10  1720.2   320.0   320.0  
   Cabinet_hi describes a high temperature chilled cabinet
12 Cabinet_lw    800.0  10  1777.1   320.0   320.0  
   Cabinet_lw describes a low temperature frozen cabinet
13 cold_store    228.0   6   257.0     0.0    76.0  
   cold_store is a storage for cold product at zero degrees.
14 m_vent_mix    152.0   6   222.0     0.0    76.0  
   m_vent_mix describes a mixing box for ventilation preheat
   all         47898.  179  27116.   3012.  10434.
 
The building is composition assumes a metal skin construction
built to 2008 regulations with concrete block walls separating
the sales area from the support spaces. Chilled cabinets have
been mereged into a high temperature cabinet zone and a low
temperature cabinet zone composed of insulated metal walls and
glazing which sit within a refrigerated sales zone. Overspill
of cold air is represented via scheduled mixing of air between
the cabinets and the refrigerated sales zone.

Fresh air requirements for up to 400 occupants are passed through
a roof-top mixing box where air (6 litres/s/person) is tempered 
to XC prior to delivery to the sales and support areas (based 
on an assumed distribution of occupants). A low rate of flow is 
used between Xh and Yh.

Air mixing between spaces and with the outside via the entrance
doors is calculated at each hour based on the current temperatures
and pressures around the building. The outer doors are assumed to
be not fully open outside the main trading hours.

The number of occupants in the sales areas include diversity. The
pattern for weekdays in the main sales area is shown in Figure 2.
Lighting casual gains are constant at 10W/m2 during the trading 
hours with reduced lighting 3W/m2 otherwise. There is little
diversity in small power loads, tyhpically 6W/m2 is used with
some support spaces having reduced small power outside trading
hours.  Pumps are assumed at 1W/m2 and fans are 1W/m2.

In general environmental conditions are controlled based on the
room use with a night set-back where appropriate. The foyer
is tempered so as to form a transition space. The space near
the chilled cabinets is held at a slightly cooler setpoint than
the dry sales area, however mixing of air occurs between the
dry sales and refrigerated sales area as well as into the foyer.

General sales area
Number of weekdays     casual gains= 27
Day Gain Type      Period Sensible  Latent     Radiant    Convec
    No.  label     Hours  Magn.(W)  Magn. (W)  Frac       Frac
weekd  1 OccuptW    0- 1   6762.6   5171.4       0.20       0.80
weekd  2 OccuptW    1- 2   5569.2   3978.0       0.20       0.80
weekd  3 OccuptW    2- 3   3978.0   2784.6       0.20       0.80
weekd  4 OccuptW    3- 4   2386.8   1989.0       0.20       0.80
weekd  5 OccuptW    4- 6   1193.4    795.6       0.20       0.80
weekd  6 OccuptW    6- 7   1591.2   1193.4       0.20       0.80
weekd  7 OccuptW    7- 8   1989.0   1591.2       0.20       0.80
weekd  8 OccuptW    8- 9   9547.2   6762.6       0.20       0.80
weekd  9 OccuptW    9-10  16309.8  11934.0       0.20       0.80
weekd 10 OccuptW   10-11  17105.4  12729.6       0.20       0.80
weekd 11 OccuptW   11-12  23470.2  17105.4       0.20       0.80
weekd 12 OccuptW   12-13  25061.4  18298.8       0.20       0.80
weekd 13 OccuptW   13-14  29437.2  21879.0       0.20       0.80
weekd 14 OccuptW   14-15  24663.6  17901.0       0.20       0.80
weekd 15 OccuptW   15-16  28641.6  21083.4       0.20       0.80
weekd 16 OccuptW   16-17  33415.2  24663.6       0.20       0.80
weekd 17 OccuptW   17-18  33017.4  24265.8       0.20       0.80
weekd 18 OccuptW   18-19  33813.0  24663.6       0.20       0.80
weekd 19 OccuptW   19-20  31028.4  22674.6       0.20       0.80
weekd 20 OccuptW   20-21  26652.6  19492.2       0.20       0.80
weekd 21 OccuptW   21-22  16309.8  11934.0       0.20       0.80
weekd 22 OccuptW   22-23  10740.6   7956.0       0.20       0.80
weekd 23 OccuptW   23-24   8353.8   6364.8       0.20       0.80
weekd 24 LightsWm2  0- 7      3.0      0.0       0.20       0.80
weekd 25 LightsWm2  7-22     10.0      0.0       0.20       0.80
weekd 26 LightsWm2 22-24      3.0      0.0       0.20       0.80
weekd 27 EquiptWm2  0-24      6.0      0.0       0.20       0.80

Figure 2 - diversity of occupancy in main sales area.

Variant models

In order to test the sensitivity of the model to assumptions
in the model a number of model variants have been tested. The
r2 case assumes that the spill of chilled air from the
cabinets is equivalent to 1 ach. The r3 case assumes 5 ach
mixing with the cabinets and the outer doors slightly less
open. The r4 case assumes 10 ach mixing with the cabinets. The
r5 variant assumes 5 ach with the cabinets but increases the
lighting to 16W/m2 in the sales areas and increases the small
power from 6 to 10W/m2.

The initial models of the supermarket used standard 2008 roof
constructions. The variants in this report include a large
area of PV panels on the south facing portion of the roof.

Assessments carried out

Initail assessments looked at a typical week in each season
and were used to identify that the description of the model
was syntactically correct. Patterns of temperatures and
environmental systems use were reviewed and adjustments
carried out.

For each of the variant models annual assessments at 15 minute 
intervals were carried out for fabric heat flows, air movement
and PV power production and a range of performance measurements
extracted.

The following predictions are discussed for each variant:

a) heating capacity required in each of the spaces
b) cooling capacity required in each of the spaces
c) heating and cooling demands in each of the spaces
d) lighting and equipment peaks /m2
e) lighting and equipment demands for the building

Table 2
 
Sensible heating load (kW) FOR R2            FOR R3                FOR R4         FOR R5
Description    Max_value Max_occur    Max_value Max_occur   Max_value Max_occur   Max_occur Min_value
Sales          38.807 09-Jan@07h07    46.769 09-Jan@07h07   50.000 08-Jan@07h07   0.0000 01-Jan@00h07
Refrig         44.766 09-Jan@07h07    83.291 09-Jan@07h07   99.999 01-Jan@05h07   99.999 09-Jan@07h22
Foyer          99.999 07-Jan@19h22    99.999 07-Jan@19h22   99.999 07-Jan@19h22   99.999 07-Jan@19h22
Office1         9.616 23-Jan@07h07    9.7261 23-Jan@07h07   9.7345 23-Jan@07h07   9.4726 23-Jan@07h07
Cafe            7.721 23-Jan@08h07    7.8844 23-Jan@08h07   7.8956 23-Jan@08h07   6.0586 17-Jan@08h07
Office3         9.333 09-Jan@08h07    9.3956 09-Jan@08h07   9.4039 09-Jan@08h07   9.1092 08-Jan@08h07
passage         2.632 09-Jan@08h37    2.6616 09-Jan@08h37   2.7381 09-Jan@08h37   2.1421 09-Jan@08h37
Staff_traing    8.855 09-Jan@08h07    8.9999 09-Jan@08h07   9.0312 09-Jan@08h07   8.8395 08-Jan@08h07
Store1          0.000 01-Jan@00h07    0.0000 01-Jan@00h07   0.0000 01-Jan@00h0    0.0000 01-Jan@00h07
Store2          3.708 08-Jan@22h22    4.4683 08-Jan@22h22   4.5671 08-Jan@22h22   3.0692 08-Jan@22h22
Cabinet_hi      0.000 01-Jan@00h07    0.0000 01-Jan@00h07   0.0000 01-Jan@00h0    0.0000 01-Jan@00h07
Cabinet_lw      0.000 01-Jan@00h07    0.0000 01-Jan@00h07   0.0000 01-Jan@00h0    0.0000 01-Jan@00h07
cold_store      0.000 01-Jan@00h07    0.0000 01-Jan@00h07   0.0000 01-Jan@00h0    0.0000 01-Jan@00h07
m_vent_mix     63.985 08-Jan@18h52    63.985 08-Jan@18h52   63.985 08-Jan@18h52   63.985 08-Jan@18h52
 
   All        164.44 08-Jan@07h07     214.35 08-Jan@07h07   250.13 08-Jan@18h52  196.72 08-Jan@05h52

As the mixing with the cabinets increased from 1ach in R2 to 5ach in R3 and to 10ach in R4
the heating capacity in the Sales and Refrig zones increased until the limit 99kW was reached. Refrig
borrowed heat from the Sales area. The difference between R3 and R5 is in the internal heat
generated within the rooms. Increased lighting and small power resulted in no heat being
required in the sales area for R5 and slight reductions in heating in the other spaces.
The heat required to temper the make-up air (m_vent_mix) is the same in all cases. The
tempering of the foyer is working flat-out at some point in time in all of the variants.

Table 3
Sensible cooling load (kW)  FOR R2     FOR R3               FOR R4               FOR R5
Description    Min_value Min_occur   Min_value Min_occur  Min_value Min_occur    Min_value Min_occur
Sales          -125.13  10-Jul@16h2  -88.424 11-Jul@16h22  -70.894 11-Jul@16h22 -126.80  11-Jul@16h2
Refrig          -14.391 11-Jul@13h2    0.000 01-Jan@00h07    0.000 01-Jan@00h07    0.000 01-Jan@00h07
Foyer           -24.434 17-Jul@13h2  -23.693 17-Jul@13h22  -23.519 17-Jul@13h22  -27.884 17-Jul@13h22
Office1         -15.219 21-Aug@13h3  -15.081 21-Aug@13h37  -15.072 21-Aug@13h37  -15.806 21-Aug@13h37
Cafe            -11.779 24-Aug@13h0  -11.145 24-Aug@13h07  -11.060 24-Aug@13h07  -12.619 11-Jul@13h07
Office3         -22.182 21-Aug@13h0  -22.193 21-Aug@13h07  -22.192 21-Aug@13h07  -22.249 21-Aug@13h07
passage          -4.236 11-Jul@14h0   -4.133 11-Jul@14h37   -4.108 11-Jul@14h37   -4.277 11-Jul@14h22
Staff_traing    -20.208 21-Aug@13h0  -19.599 21-Aug@13h07  -19.528 21-Aug@13h07  -19.769 21-Aug@13h07
Store1           -9.781 11-Jul@15h5   -9.505 11-Jul@16h07   -9.452 11-Jul@15h52   -9.632 11-Jul@16h07
Store2           -8.341 11-Jul@13h0   -7.464 11-Jul@13h07   -7.286 11-Jul@13h07   -7.654 11-Jul@13h07
Cabinet_hi      -18.847 11-Jul@17h0  -32.279 11-Jul@16h52  -48.667 11-Jul@17h22  -49.316 11-Jul@16h52
Cabinet_lw      -36.124 11-Jul@17h0  -65.491 11-Jul@16h52  -99.999 08-May@16h07  -99.999 25-Mar@16h37
cold_store       -5.037 11-Jul@10h2   -4.951 11-Jul@10h22   -4.935 11-Jul@10h22   -4.958 11-Jul@10h22
m_vent_mix        0.000 01-Jan@00h0    0.000 01-Jan@00h07    0.000 01-Jan@00h07    0.000 01-Jan@00h07
 
   All         -288.74 11-Jul@15h22 -277.04  11-Jul@15h22 -311.23  11-Jul@15h22 -375.48  11-Jul@15h22 

Cooling capacity in Sales tends to reduce as the mixing with the chilled cabinets increases
because the Refrig zone gets more of its cooling requirements fromm the overspill from the
chilled cabinets. The R5 variant re-establishes the higher cooling capacity to balance
the higher casual gains.  Increasing lighting and small power has only a small impact on
most room cooling capacity. 

Table 4
 Zone total sensible and latent plant used (kWhrs)  R2       FOR R3
    Zone             Sensible heating  Sensible cooling    Sensible heating  Sensible cooling
 id name             Energy   No. of   Energy   No. of     Energy   No. of   Energy   No. of 
                     (kWhrs)  Hr rqd   (kWhrs)  Hr rqd     (kWhrs)  Hr rqd   (kWhrs)  Hr rqd 
  1 Sales            233.72   20.0 -134926.69 3454.8       679.65   51.0  -35385.57 1451.5   
  2 Refrig          2699.46  283.8   -2431.60  597.8    161186.16 6294.5       0.00    0.0   
  3 Foyer          46561.97 2148.5   -2100.33  357.5     53243.55 2398.0   -1868.03  329.3   
  4 Office1         2114.17  857.3  -15406.94 3054.0      2335.39  943.3  -14636.46 2915.0   
  5 Cafe             945.14  657.0   -8165.82 2218.8      1171.32  810.8   -7067.83 2063.0   
  6 Office3          571.30  274.8  -28458.12 4078.3       635.91  309.8  -27824.65 4053.3   
  7 passage          353.11  648.0   -3191.54 2318.3       497.04  882.5   -2817.52 2146.5   
  8 Staff_traing     563.61  297.0  -25420.32 4012.3       686.87  345.8  -23834.44 3930.0   
  9 Store1             0.00    0.0  -18743.18 4802.8         0.00    0.0  -15395.30 4036.8   
 10 Store2            75.81   61.0   -3695.21 1283.3       151.14  128.0   -2419.48  948.3   
 11 Cabinet_hi         0.00    0.0 -131359.00 8760.0         0.00    0.0 -234899.39 8760.0   
 12 Cabinet_lw         0.00    0.0 -280841.78 8760.0         0.00    0.0 -524840.69 8760.0   
 13 cold_store         0.00    0.0  -29314.04 8760.0         0.00    0.0  -28600.28 8760.0   
 14 m_vent_mix     89088.31 7423.8       0.00    0.0     89088.55 7423.8       0.00    0.0   
 
    All           143206.6 12671.0 -684054.5 52457.5    309675.6 19587.3 -919589.6 48153.5   

 
 Zone total sensible and latent plant used (kWhrs) R4       FOR R5
    Zone             Sensible heating   Sensible cooling   Sensible heating  Sensible cooling 
 id name             Energy   No. of    Energy   No. of    Energy   No. of   Energy   No. of  
                     (kWhrs)  Hr rqd    (kWhrs)  Hr rqd    (kWhrs)  Hr rqd   (kWhrs)  Hr rqd  
  1 Sales            812.38   54.0   -23753.44 1288.5        0.00    0.0  -185016.66 4612.0    
  2 Refrig        619012.25 8760.0        0.00    0.0   343427.47 8430.0        0.00    0.0    
  3 Foyer          53656.20 2412.0    -1830.34  322.5    39841.71 1896.5    -3593.26  514.5    
  4 Office1         2354.36  949.0   -14567.83 2906.0     1785.75  740.8   -17692.93 3420.8    
  5 Cafe            1190.94  824.0    -6958.41 2049.0      405.65  309.5   -10510.06 2573.8    
  6 Office3          641.31  313.8   -27763.03 4049.5      476.17  224.0   -29035.07 4109.0    
  7 passage          515.34  899.3    -2779.77 2131.8      161.32  319.3    -3441.13 2487.8    
  8 Staff_traing     693.88  348.3   -23696.21 3920.0      551.28  292.3   -24691.31 3998.0    
  9 Store1             0.00    0.0   -15070.03 3985.5        0.00    0.0   -18160.99 4913.8    
 10 Store2           160.52  136.0    -2285.63  915.5       37.56   37.5    -2829.06 1071.0    
 11 Cabinet_hi         0.00    0.0  -385244.19 8760.0        0.00    0.0  -391748.56 8760.0    
 12 Cabinet_lw         0.00    0.0  -851216.50 8760.0        0.00    0.0  -856923.25 8760.0    
 13 cold_store         0.00    0.0   -28542.37 8760.0        0.00    0.0   -28926.11 8760.0    
 14 m_vent_mix     89088.41 7423.3        0.00    0.0    89088.03 7424.0        0.00    0.0    
 
    All           768125.5 22119.5 -1383707.7 47848.3   475774.9 19673.8 -1572568.4 53980.5      
  
The annual demands for heating and cooling are seen to be sensitive to the rate of mixing
with the chilled cabinets (R2 R3 R4) and to the level of casual gains (R5).  In particular
The heating associated with Refrig varies from  2699.4 to 161186.1 619012.2 with 
increasing mixing with the chilled cabinets. The mixing increases the cooling needed
within Cabinet_hi from -131359 to -234899 to -385244 and within Cabinet_lw from
-280841 to -524840 to -851216.

The overall ratio of heating & cooling demand for R2 is 0.209, for R3 0.336,
for R4 0.555 and for R5 0.3025.

The electricity associated with cooling Cabinet_hi Cabinet_lw and cold_store is
roughly 0.33 * the cooling demand: 
 
R2 (131359 + 280841 + 29314) * 0.33 = 145699 (kWhrs)
R3 (234899 + 524840 + 28600) * 0.33 = 260151 (kWhrs)
R4 (385244 + 851216 + 28542) * 0.33 = 417450 (kWhrs)
R5 (391748 + 856923 + 28926) * 0.33 = 421607 (kWhrs)

Electricity associated with cooling the other spaces is roughly 0.25 * cooling demand:

R2 (134926 + 2431 + 2100 + 15406 + 8165 + 28458 + 3191 + 25420 + 18743 + 3695) * 0.25 = 60633 (kWhrs)
R3 (35385 + 0 + 1868 + 14636 + 7067 + 27824 + 2817 + 23834 + 15395 + 2419) * 0.25 = 32811 (kWhrs)
R4 (23753 + 0 + 1830 + 14567 + 6958 + 27763 + 2779 + 23696 + 15070 + 2285) * 0.25 = 29675 (kWhrs)
R5 (185016 + 0 + 3593 + 17692 + 10510 + 29035 + 3441 + 24691 + 18160 + 2829) * 0.25 = 73741 (kWhrs)

Lighting as follows:

R2 543477.0 (kWhrs)
R3 543477.0 (kWhrs)
R4 543477.0 (kWhrs)
R5 816205.0 (kWhrs)

Small power  as follows:

R2 397712.0 (kWhrs)
R3 397712.0 (kWhrs)
R4 397712.0 (kWhrs)
R5 691401.0 (kWhrs)

PV generation from the roof panel is: 262740 (kWhrs)
 
 
 
 
 
 
 

   
  
  
  
  
  
  
  
  
  
  
  
  
  
  

  














 
 
 
 
 
 
 
 
 
 
 
 
 

 














 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
