THE MEASURED PERFORMANCE OF L()R ENERGY PASSIVE SOLAR HOUSES FOR

Transcription

1 THE MEASURED PERFORMANCE OF L()R ENERGY PASSIVE SOLAR HOUSES FOR Robert W.. Besant Tan Hamlin Jom RovJe Department of Mechanical Engineering University of Saskatchevlan Saskatoon, Saskatchewan Canada sm awo ABSTRACT In this study, 14 Jow energy passive solar houses in a 6 C-day climate have been rnonitored. for energy collf3umption for a period of one yeare The houses were commercially designed, constructed, and marketed by thirteen different companies during 198 in Saskatoon, Saskatchewane These houses were part of a government and construction industry sponsored show heme "display located on one city block@ All the houses featured many energy conservation and passive solar components including airtight air vapour barriers, three to four times the required insulation levels*, air to air heat exchangers, low energy furnaces and space heating systems located in airtight furnace rooms, south facing windows with up to four glazing layers, and sane special features such as passive hot water preheater tanks, Trambe walls, night shutters, attached sunspace greenhouses, air lock entrances, etc@ Three levels of monitoring were used; namely, gross natural gas and electrical energy consumption, special short term component testing in situ and in sulated laboratory conditions, and dynamic thermal comfort and energy monitoring with 3 channels of data The results of these investigations revealed that the houses consumed only about one half to one third the total space heating energy of that of standard housing Tests on components revealed a number of significant differences between measured results and standard design informationllo Attic insulation, basement floors, furnaces, air to air heat exchangers, night shutters, Trcmbe walls, and sun spaces all performed significantly below expectations walls, RSl35 (R2) Solar gains in winter were significantly below expectations I' but summer gains sametes caused overheating and thermal discanforto A large number of design and installation reccmnendations have resulted from these investigations 1 The fourteen low energy passive solar houses in Saskatoon were designed by thirteen construction canpanies, and were intended to demonstrate the practical application of low energy passive solar houses in reducing fuel bills for space heating Reduced auxiliary space heating requirements were to be achieved by the use of high levels of insulation, air tight air-vapour barriers, air to air heat exchangers, south-facing windows and small gas fired furances in air tight furnace roomse The main features of the thermal design of each house are summarized in Table lg All the houses had families living' in them during the heating season with the exception of Ml which was a special empty test house up until January 1982 Two predictions were made for the expected energy consumption for space heating in each house The first was based on standard values of performance of each component based on engineering literature, design specifications and the manufacturers claimse The second included modified performance values based on the test results for each component in each house $ Both calculations used a steady state model with appropriate solar utilization factors, and weather statisticso 2. METHOD OF ANALYSIS The method of analysis in this study was to assume each house to operate under -172-

2 different but steady conditions of tempera1:ure, air exchange, solar radiation, and auxiliary space heat energy demand each month of the year The ambient weather conditions are taken from the measured data for Saskatoon for each month of the year Solar radiation data for south-facing windows was established from measured average monthly horizontal data (6 Each thermal canponent of the house was assumed to have constant thermal properties That is, walls, ceiling, doors, windows, etc., were assumed to have a fixed resistance to heat flow, usually that specified in the design information for each house. Assuming steady state conditions with no storage of energy, the auxiliary energy expected was computed as the difference between heat losses and heat gains fran people, electrical appliances, and solar gains It is noted that only a fraction of the solar energy is assumed to be available for space heating (1, 2) This empirical correlation used to estimate the useful solar gains is based on studies done on test cells. Dynamic modelling is being carried out to verify these correlations and will be available in the future. 3. RESULTS The monitoring results are presented as monthly average consumptions and weather data. These are then compared with design predictions The measured results of energy consumed for space heating in each house were taken fram March 1981 to March 1982@ The main results of these data are presented in Tables 2, 3 and 4 for the ambient weather, fuel consumption, and air to air heat exchanger flow rates 3.1 The computed results for each house are presented in Tables 5, 6, 8 and 9", First a standard computer run for each house was used to establish the performance from the information as presented in blue prints for each house... In this the basement floor heat losses were sumed to be a constant value of 8 W/m (3) 19> These results are briefly summarized in Tables 5 and 6 The results include the measured value of electrical gain, estimated people gain, and air to heat exchanger heat recovery as based on air flow measurements@ It can be seen fran the results in Table 5 that heat losses from well insulated canponents such as the walls, etc. 1 are only a small fraction of the total heat losses, which include air infiltration and uninsulated windows and basement floors", In Table 6 the useful. space heating solar gains were calculated to average 12 GJ per year which represents 37 percent of the auxiliary space heat or 16 percent of the total heat loss but useful gains from people and electrical sources are nearly three times as large 19 It is noted that all internal gains from people and electrical sources were assumed to be useful when space heating was required, but only a fraction of the solar gains were assumed to be useful during the heating season where the solar load ratio was used in computing the useful solar gains (I). It should be made clear that not all the gains of energy are useful in providing space heat@ Electrical and people gains during the sumner are often unnecessary and would cause overheating unless extra ventilation of air were provided '" In the case of solar gains excess energy may have to be vented over several months depending on the particular house and how it is operated For example, a decrease in energy conservation measures would result in higher heat losses, but slightly more useful electrical, people and solar gains The net effect of this would be a larger auxiliary sce heat load", 3.2 In the computed standard design analysis results, Table 5 implies that errors in computing heat losses through air infiltration or basement floors would result in much larger total heat loss errors than would an error in ceiling or wall heat losses", Furthermore Table 6 suggests that gains fran people and electrical sources are much more important than solar gains in these houses In this study the effects of design errors in the heat loss canponents were examined in sane detail by testing each component The three canponents of heat loss which were of greatest concern are: (i) (ii) (iii) the air infiltration the ceiling attic and the basement f1rs The ceiling attic was considered because other tests suggested that the design data used in this first standard design analysis were incorrect (4) The standard uninsulated basement floor heat loss analysis was shown to be in considerable error in a previous report (5) Air infiltration losses are the most difficult to accurately assess since they depend not only on the original design and construction, but on the operational mode of the air to air heat exchanger and the people using doors and windows (6) -173-

3 32ol Air ventilation The measured air floylt rates in the air to air heat exchangers show that these flows were unbalanced. Usually, more air was entering the houses through the heat exchanger than was leaving through the heat exchanger <8> As a consequence, it was assumed in the modified computer runs that this difference in flow rate was made up by exfiltration (or infiltration in the case of excessive exhaust air flows) through the cracks in doors or windows, or through holes in the air-vapour barrier. The heat exchanger efficiency was measured for each house and derated by this flow imbalance to obtain the expected performance of each air heat recovery system (6) A minimum ventilation rate of.25 air changes per hour was assumed except where houses showed poor pressurization test results (Cl and C4) or air exchangers were known to have hyperventilated (82) or lower air change rates were suggested by high humidity, odors and other air quality factors (Al and The' measured depth of ceiling insulation in each house along with the measured compression test results are presented in Table 7 This compression test was carried out by placing a 7 d mass of area one foot square (34 kg/m ) on the insulation near the attic hatch and measuring the depth of insulation under the mass In this study, it is assumed that the compressed depth of insulation is a better indication of the amount of insulation and its insulating value than the original installed depth of insulation. It is noted that these depth tests do not include any differences in depth that might exist in any particular attic, especially under the roof eaves where placing insulation might be more difficulte Finally, the results of these depth tests were used in conjunction with a laboratory established thermal resistance per unit depth Using a large model of a typical attic, test results on a particular blown insulation were carried out, not under ASTM: standard conditions of average temperature, but similar to attic operating conditions of installation, insulation depth, and temperature difference across the insulation The laboratory results reported in detail in (4) show a reduced insulating effect, especially, at large temperature differentials@ From this laboratory information and other available data, an expected value of attic ceiling insulation was calculated using correction factors for the expected depth of i1jstalled inslation at a density of 8 kg/m C,5 lb-!ft ), K, the manufacturers RSl per unit llaepth,. K I, 2 the estimated effectiveness correction factor of the insulatbon fran the laboratory test at 3 C temperature difference, K, the estimated insulation temperature correction factor for an interior house temperature of 2 C and exterior temperate of -looc, K, and th r 4 compressed depth D l!i Thus, RS I -I - = D KKK K ce1 1ng wer 3 4 giving Finally the blown fibreglass was supplemented in October 1981 with additional blown fibreglass after the original material was compressed $ This retrofitted attic insulation in 7 houses would bring the attic insulation up to the design valuese These new values were used in the wintere ,. K l = 1.74 K 2 = 13.3 RS l/m depth K 3 =.564 K 4 = 13 1 RSl -1- = 17@ D ce1 1ng The design RSI values and the estimated effective RS I values for the ceiling of each house are compared in Table 7 e The later value is used in the second computer run for each house where applicable The standard design computer run results on the low energy houses incorporated a standard value for heat loss to the uninsulated basement floors of 2 GJ per monthe A calculation of heat flow rates to the floors using measured temperature data reported in a separate report (6) indicates that the heat flow rates to these uninsulated basement floors were very much higher than anticipated using standard calculation procedures As a consequence, the computed heat loss fraction through the basement floors, while large in the standard design computer run, Tables 3, 5 and 6, was measured and computed to be very much larger, Tables 8 and 9. These results suggest a need for more experimental data and new correlations for basement floor heat losses igl In the modified second computer run for each house, the basement floor was examined for its exact area, floor covering, things placed on the floors, and air distribution as reported in (5) $ Using standard heat transfer calculations, a modified heat loss rate was used for each house basement floor\'» The calculation assumptions used to estte heat losses from the basement -174-

4 floors in the 14 low energy passive solar houses are as follows: (a) The furnace was on 25 percent of the time for the months of November, December, January, February and Marche The remaining portion of the time there was no air circulation in the basements during these five months (b) (c) The furnace was on 12 1/2 percent of the time and no air was circulated 87 1/2 percent of the time during October and Aprile No air was circulated. in the basements during the five remaining months of the yeare (d) The basement temperatures were measured with and without furnace operation and heat rates were estbnated from this data Some measured temperatures and soil basement floor temperatures are presented in Figure 1" These measured floor temperature data were used in conjunction with basement air circulation rates and furnace on tes to predict basement floor heat losseso It is noted in Figure 1 that in sane cases (NI, Ml, M2 and 81) the basement followed a similar floor profile temperatures to the soil temperatures near the houses and the long term averages away fran houses In other cases (Al, 83, VI and C2) basement floor temperatures appeared to digress from this profile during the heating season It is thought that this difference may be due to the method of heating the basement floor!ii Sane houses provided heat mostly during the heating season (Al, S2, 83,. VI and C2), some provided little direct heating at any time (Ml and Nl), while one provided heat over the entire year (81) <ld The dynamics of basement floor heating is further illustrated in Figure 2 for house A1 In this comparison of space heating and basement floor temperature as a function of days in time the dynamic coupling of space and the floor is evident<lo The basement floor heat loss calculation is not expected to be very accurate but it is thought to be better than the existing steady state methods and is meant to illustrate the complexity and uncertainty in the prediction of uninsulated basement floor heat losses The method is not suited to the design process as it requires radiation temperatures, floor covering estimates (carpet, furniture, storage areas, etc ill ), air circulation characteristics and temporal variations and estates of capacitance effects in floor temperatures The modified values of basement floor heat losses, attic losses and infiltration losses were ncorporated into the computer program. Auxiliary heat demands were taken to be zero for June, July and August as was done for the standard design rune Table 8 presents a summary of the heat losses for each component<& A comparison of these values with those in Table 5 shows that the heat losses fran air ventilation, attic insulation and basement floors is computed to be larger than the original estimation. In addition to the heat loss components performing sanewhat below expectations, sane of the canputed heat gain components were also in question The heat gain components examined were the furnace space heating system and solar gains through south facing windows Each house except El was fitted with an air tight furnace roam in the basement which was intended to reduce uncontrolled air infiltration El had a combined danestic and space heat hot water heating system These furnace roans contained the furnace apd hot water heating tank, both gas fired Natural air ventilation to the furnace roans to provide canbusion air was achieved by a 15 em diameter open duct to the outside House S3 had two such ducts in the furnace room,. one discharging low down and the other near the ceiling The overall efficiency of heat transfer from the furnace to the house was not just the efficiency of the furnace which averaged about 67 percent (6) 1ll Rather the furnace roam efficiency determines what fraction of combustion energy is transferred to the house This overall furnace room efficiency ranged between 4 and 7 percent depending mostly on the duration of burn periods4 > For house S3 it is expected to be considerably less due to continuous air circulation to the outside fran the furnace rocmlll The heat gain frcm south facing windows was computed to be a significant source of heat gain, however, direct measurements of these gains indicated that gains through south facing wind\t,7s depends on more than just the angle of incidence and scme shading factor <II It is shown in a separate study (8) that the transmittance of windows depends on the type of window the air mass and any ice crystals, clouds, snow, through which solar radiation is transmitted$' In general the transmittance of windows is significantly reduced in winter especially for large numbers of glazings. Poor overhang geanetries also resulted in reduced solar gains in at least one house (82) <II Lack of edge seals on large heat mirror curtans or night shutters also reduced trambe wall performance in Cl and C4-175-

5 Improved solar utilization curves (2) based on test hut measurements in Ottawa, Ontario were also used in the modified runs. These show somewhat more solar utilizability at low solar gain load ratios than do earlier results (1). The modified component performance data for heat losses and heat gains were used to again predict the annual performance of each house in Table 9 As a measure of validity of the second means of calculation Table 9 compares the measured auxiliary energy conslnnption for space heating with the two methods of computing these valueso The measured auxiliary space heating load was calculated using the total energy conslnnption for each month and subtracting the measured amount of energy used in July and August Table 9 is presented with data for the standard basement heat loss as well as the corrected estimate to further illustrate the importance of the basement heat losses It can be seen from Tables 5, 6, 8 and 9 that the standard design run under-predicts auxiliary energy demand by nearly a factor of two whereas the modified runs give values that on average are within five percent of the computed total heat loss or six percent of the auxiliary energy used The two methods of computing errors presented in Table 9 reveal quite different results Error nan, based on the projected auxiliary space heating requirements canpared. to measured consumption, indicates the sensitivity of the error in computation or estimation to the measured amount of space heating Error nb n, based on the total calculated heat loss, presents the sensitivity of the computed results to the total potential heat 1ssill It is noted that error nan, based on auxiliary space heating, leads to error fractions since the auxiliary space heating load is calculated from the difference between the losses and the The smaller the space load the this error gj Error 'IBn perhaps a better measure of the accuracy of the heat loss calculation as this error fraction cannot blow up to values greater than 1 percent 4" It -_ ,... can be seen fram measured and the results space on 1 energy houses that the original calculation methods rise to large errorse Subsequent of components indicated that the fran basement floors, attic and air infiltration were much expectecl In addition the heat fram furances windows were less and south facing than expected ill Calculations using the revised canponent information gave much better correlations with measured datae The low energy houses investigated in this study were designed in 198 using information available fram standard design information sources These low energy houses, designed and constructed by thirteen different companies, represented a significant departure from standard design<r. The resulting space heating performance of each house depends not just on the design features, but on 'the operational procedures used to reduce energy consumption The more energy efficient the house the greater is the importance of the operational methods A lack of knowledge by house owners has resulted in poor performance of same canponents such as air to air heat exchangers, thermostat settings combined wi th door and window usage and hot water usage Gll As people were not given instructions by the house contractors sane houses were hyperventilated with the air to air heat exchanger (S2) and sane heat exchangers were not operating properly (frosted, etc\&) due to unbalanced flows (Sl, PI, C2, S2 and M2), air leakage (El, PI and AI), frosting (M2, S3, Al and 81) and air preheating in ducts (Ml, El, PI, VI and C4) This caused humidity and dryness problems which were not recognized by the occupants as heat exchanger problems'll Thermostat settings and use of doors and windows significantly affect the heating load Hot water heating requirements are of the same magnitude as space heating and are highly influenced by operational rnethods Electrical usage also varies considerably but since most of this energy ends up as internal thermal energy it is useful during the space heating season 5" In this paper fourteen different commercial low energy passive solar houses were measured, tested and analyzed for space heating energy use The predesign predictions of energy use indicated expected annl spacing heating fran 7 to 4 KJ/ (DO... m ) whereas measured V2lues ranged from 249 to 854 KJ/(OO... rn ) Testing of thermal canponents revealed significant deviations between measurements and predesign assumptions and calculations Uncertainties in the calculation of canponent heat losses are still significant in the modified computer runs which included measured component data These uncertainties would amount to about 4 percent of the basement floor heat loss or between 1 and 2 GJ per heating -176-

6 season, 25 percent of the air infiltration 'heat loss or between 2 and 5 GJ per year and 1 percent of the above ground envelope heat loss or between 1.5 and 3 GJ per year The overall uncertainty in the modified calculation is expected to be about 25 percent for total heat loss. It is noted that these uncertainties are somewhat consistent with the standard deviation errors and between operational variations that exist among the house occupants OIl This study has identified the important heat loss and heat gain canponents in some commercial low energy passive solar houses. The implications of this study are that significant improvements in the performance of such low energy houses are best achieved by improving certain canponents, especially basement floors. It is expected that for modest changes in design and costs significant improvements in performance are possible provided owners operate the houses in a fashion to attain lower energy consumption 1. W@ Wray, J D@ Balcanb and RoD'l' McFarland, SUA Semi-Empirical Method for Estimating the Performance of Direct Gain Passive Solar Heated Buildings", 3rd National Passive Solar Conference, AS/ISES, ROllS. Dumont g DBR, NOC, Saskatoon, Sask.. ) _.LL.\I'LLIf...= ccmnunicatione 3. J.K. Latta and G.G. Boileau, "Heat Losses from House Basements", DBR, NRC, Housing Note 31, October R4IlW. Besant and E. Miller, "Test Results fran a Laboratory Model of an Attic Insulated with Blown Fibreglass", Report, Department of Mechanical Engineering, University of Saskatchewan, July 1981G 5. R<lIW.. Besant and TOll Hamlin, ua Preliminary Report on the Uninsulated Basement Floor Heat Losses in 14 Low Energy Houses in Saskatoon, Sask. II, Report, Department of Mechanical Engineering, University of Saskatchewan, July Tam Hamlin and R.W. Besant, nair to Air Heat Exchanger Performance Results", Report, Department of Mechanical Engineering, University of Saskatchewan, February 1982@ 7. ROIIW. Besant, T. Hamlin ands. Bengston, "Furnace Performance in the Low Energy Passive Solar Show Homes in Saskatoon", Department of Mechanical Engineering Report, University of Saskatchewan, February RWO Besant and Tan Hamlin, utransmittance of Multilayered Windows with High Air Mass and Ice Crystals Aerosols in the Atmosphere n, Department of Mechanical Engineering Report, University of Saskatchewan, April 1982 TABLE 1.. DESIGN ENERGY FEATURES FOR 14 COiVIMERCIALLY CONTRACTED IfJW ENERGY HOUSES IN SASKATOON, SASK,. (lat 52 6') Hc.use Cod Nominal Windows Window Nominal Insuliltion Area South Other Shutters I I Basement Ceiling Wall m2 Floor (m l walls 'a 11 ) Ara Glaz.. Area Glaz... RSI RSI RSI Type(l) m lhgs m 2 logs Orientation Km2 w.. 1 HI looo 1.4 &1 'L OS E ,, _". OS Sl S :$ 7.3 J... 6 B * PI J _... OS Cl (16.4)souh SlY VI EL Sl... _- C OST Ai j DST C3 115.B L 7 3 (2.6)north OST : Sh' C :5 (13.B)5Uth S\ HI 12.9 fl4 : _.. OS S Sh' i-12 Ol.S OS Ave B '5.2 Std. Dev , Note: 1. DS... Double stud exterior walls, OST... Single stud exterior walls with interna.l horizontal strapping, SW... single stud exterior walls. *" Vapor barrier on inside of inside wall

7 TABLE 2.. WEATHER DATA FOR SASKA'IOON (lat 52 6 I ) fe.an Temp. Heating Degree iean Tota1** Percent Total C'C) Days Wind Bright Pcssible Global (18 e Base) Speed Sunshine Bright Radiation (km/hr) (hr) Sunshine (lou/m 2 ) Mar '81-1.5(-7.9)* 594(83) 11.3(18.) 183(192) 5(52) 386(423) Apr 5.5( 3.4) 373(433) 15.9(18.) 253(225) 61(54) 57(519) May 12.5(11.2) 178(214) 16.9(2.3) 25(278) 42(58) 666(659) June 15.(15.6) 97 ( 96) 13.2{18.7) 299(28) 65 (56) 639(683) July 19.(19.1) 21 ( 28) 12.(17.1) 31 (341) 6(68) 63(737) Aug 2.5(17.7) 14 ( 43) 11.(16.7) 317(294) 7(65) 58(64) Sept 13.5(11.3) 16(197) 13.4(19.) 2(27) 63(55) 39(41) Oct 3.( 5.4) 462(47) 16.(18.7) 14 (175) 32(53) 198(256) Nov.5(-5.4) 531(713) 12.7(17.9) li5( 98) 44 (37) 115(129) Dec -13.(-13.8) 969(967) 12.8(17.4) loot 84) 42(35) 14(97.5) Jan ' (-18.9) 1386(883) 12.5(17.3) 122( 99) 48(39) 146(133) Feb -1.5(-14.1) 95(928) 13.7(16.4) 141(129) 51 (47) 219(233) Mar -8.(-8.3) 812(83) 15.6(18.) 157(192) 43(52) 319(423) * Longterm average values in brackets ** Stokes-Campbell Measurement TABLE 3.. E:r"dTffiGY CONSUMPTION AND OAICUIATED PERFORMANCE OF 14 COIYlMER... CIALLY DESIGNED AND CONTRACTED IJJfiJ ENERGY HOUSES IN SASKA TOON (lat 52 6') H 5, 1981 TO MARCH 2, 1982 Induced Air Change at 5 pa ACH-l Nat. Performance Space Heating Energy , CJ S C4 29. L Nl H * Ave Std Dev..45 NOTES: 1. heating value taken as MJ m- 3 one fifth of water used assumed 283 MJ m- J (331 Kwhr of space heat assumed in house Ml). 2. Saskatoon received 5734 DO relative to 18 C base (-1,5 DD relative to 65 F base) for the measurement period. estimated + predesign predicted using total heated floor area -178-

8 TABLE 41 AIR ro AIR HEAT EXCHANGER RESULTS HOUSE' AIR FLl1 RATES (lis) TEtPERATURES (Oe) HEAT EXCU. R.II. E T ErR 11 MAKE IIOT EXHAUST COLD FRESH INTAKE T hi Tho T T ci (%) In Out In Out co Ratio COl-tr-tENTS _.. n DC 18t ls±j PHheating of air in ducts, empty house EI Ut NA 51 DC ± 'l..h.o M<J :55 Preheating of air, un balance 15±3 16±3 32± and crossflo\i Pl Nit :t Un balanced, preheating C2 DC 23:t3 2:t ±3 23±3 26:t3 28: Al Ut 16±2 IOt ± meaningless Severe crossflow VI DC 19± ± Preheating of air, insulatcc.l but long ductng C3 DC NA 52 Ener 41:13 8:tS 41:t3 49± I Continuous operation C4 DC ±2 22± IB.O Preiaeaing of air Nl DC 32±3 32±2 3M3 38± S3 "Ut f3 9±3 31t3 NA Severe crossflow 12 DC 1± Lint blocked 7±4 14±4 35± B Frosted JOt4 3± r 1NI temperature rcovery R IllIIi mass' flow imbalance, n l<jll heat recovery TABLE 5.. ANNUAL STANDARD DESIGN ANALYSIS RESULTS OF HEAT IDSS CQVlPONENTS FOR 14 J.iJfil ENERGY PASSIVE SOLAR HOUSES IN SASKATOON, SASKATCHEWAN Al i Cl J J '27. J J<)'2 8.5 C : CJ UL C O HI O b 9. N J L Nl J <) PI i L J J 7. ] ! J Vi 6.9.oal) 7. ' ) UL H <) Dev ' of component heat loss to component. total heat loss from all components usi.ng precol11:itruction +.25 ach ventilation rate with.6 air to air heat exchanger effic.:iency assuliid

9 TABLE 6.. ANNUAL STANDARD DESIGN PREDICTED AND MEASURED HEAT ross AND ENERGY USE FOR 14 row ENERGY HOUSES.. DISCREPANCIES BErWEEN PREDICTED AND MEASURED AUXILLIARY SPACE HEATING REQUIREMENTS ARE INDICATED BY EBRORS A A.T\ID B.. Predicted Actual Gas Total Heat Useful Solar Useful Natural Gas Error A C Error B d House Loss (GJ) Gain (GJ)a Gain Consumption (GJ) Consunlption (GJ) Al Cl H C C O.bl -.4 C E Ml I M \-1 CO Nl I PI SI S S) J ] VI Mean Std. Dev NOTES: (a) Useful annual solar gain was computed from long term monthly average data with shading factors for double, triple and quad glazed windows of.8,.7 and.6. (b) Useful internal gain includes electrical gains (measured), people gains (3.7 GJ/person-year) and hot water gains (.26 x.55 x hot water tank consumption). (c) Error A ;:: (d) Et"ror B ;:: annual space heat energy annual space heat energy difference relative to the total calculated energy loss.

10 TABLE 7.. r-1easl1ent OF A'ITIC CEILING nsui.j'\ion DEPTH A.l\ID PREDICTED INSULA TION TIVENESS rn FOURTEEN' IDW ENERGY HOUSES IN SASKATOON, SAS KATCHEWAN.. HOUSE: TYPE OJ: INSULATION J.1ANUFACl1JRERS INSTALLED DEPTIi (m) DEPTH UNDER rest leighr (m) D 1 DESIGN RSI C'em 2 /w) EXPECTEL' RSI CC:l2/w) r-11 El 51 PI Cl C:Z AI VI C3 52 C4 Nl 53 M2 Blown Hodulated blow1'1 Blown FG Modulated Blown FG bat'ts.modulated.blown.fg 5P blown FG 5P blown FG SP blown FG SP blown FG 5P blown Blown FG SP blown FG SP blown FG 3M JM Jli NA : NA ' NA & AVERAGE VALUE STANDARD DEVIATION TABLE 8.. ANNUAL IvlODIFIED DESIGN ANALYSIS RESULTS OF HEAT LOSS COMJ?ONENTS FOR 14 IDW ENERGY PASSIVE SOLAR HOUSES IN SASKATCXJN f SASKArrcHEWAN '" Ceiling Ratio CJ Infiltration CJ Ra till U e ') OOB ') O e ILk VI IB Average Std De\! ')

11 TABLE 9.. PREDlcrED AND :MFASURED ANNUAL SPACE HEATING ENERGY FOR FOURrEEN IDW ENERGY HOUSES INCLUDING Balli A JYDDIFIED BASEMENT FLOOR HFA.T ross CALCULATION AND A STANDARD BASEMENT FLOOR HEAT LOSS.. DISCREPAN CIES BErWEEN PREDlcrED AND.MEASURED AUXILLIARY SPACE HEATING REQUIRn1ENTS ARE INDICATED BY ERRORS A AND Be> Calculated Predicted Predicted Measured House Total Heat Useful Auxilliary Natural Gas Natural Gas Error A.c) Error B (d) (e) Loss (GJ) Gain (GJ) Heat Consumption (GJ) Consumption (GJ) Al M/S 77.8/ / / / / / /-.22 Cl MiS 76.5/ / / / / / /-.26 C2 M/S 86.2/ / / / / /-.51 C3 M/S 81.4/ / / / / / /-.41 C4 H/S 13.7/ / / / / / /-.42 El M/S 82.9/64.6.8/ / / / /-.34.1/-.15 Ml M/S 82.5/ / / / / / /-.15 H2 MiS 75.6/ / / / / / /-.33 I Nl MiS 86.9/ / / / / / /-.12 f--l CO N I PI H/S 84.5/7.9 9./ / / / / /-. 31 SI MiS 15.8/ / / / / / /-.12 S2 M/S 82.9/ / / / / / /-.53 S3 M/S 17.2/ / / / /-.33.6/-.33 VI M/S 12.3/7.2.1/ / / / / / / / / / / /17.3.6/.2.1/ / / / / / /.14 NOTES: (a) Useful annual solar gain was computed from measured data with shading factors for double, triple and quad glazed windows of.8,.7 and.6. (b) Useful internal gains wer-e calculated as in Table 6. (c) Error- A was calculated as in Table 6. (d) Err-or B was calculated as in Table 6. (e) M/S refers to the modified basement floor heat loss case / standard basement floor- heat loss case. (f) Aver-age/a refer-s to the average value standard deviation for the modified basement floor heat loss case. (g) refers to the aver-age value standard deviation for the standard basement floor heat loss case.

12 f u / '-" (1) H.a.J co 11 (I) o.c 1 e (I) E v - VI S - hol.j"' 51 A - },OV-Gi 4\1 N - hotj-1lib NI # - hotj-'&'lii 52 hou X - hou... <fi&,.2 H - }-..o\.jp'!iill HI C - hotj... 1lIB C May Jun Fig 1 Measured Floor and Soil Temperatures -183-

13 22. FLOOR TEMPERATURES eo "..." U '--" <1J $-I ;:j.w C"d H <1J p.. S <1J.w $-I r-1 2 1geO 18eO 17. I f-l I 1r 9 "..." (Y') 8.w 4-i '-.:./ 'r-!.w p s ;:j (J) 4 CJ <1J CJ C"d C $-l ;:j Feb" Time (days) 2 Measured basement floor temperature and furnace natural gas consumption Dece 4, 1981 to Mare 24, 1982