THE "COST" OF ENVIRONMENTAL CONTROL WITHIN BUILDINGS

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2 TH "COST" OF VIROT COTRO WITHI BIDIGS BIDIGS as illustrated are essential to shelter people, animals, processes and products. Internal conditions have also to be controlled for the comfort and health of the occupants and to protect processes, products and contents. FORTTY, as depicted. half the atmospheric pollution in the K results from the emission of greenhouse gases produced by fossil fuels being burnt to provide energy for buildings. ISSIO in Kg of CO2 per kwh of energy delivered, due to burning hydrocarbon fuel equates to: lectricity 0.72 Solid Fuel 0.34 Fuel Oil 0.29 Gas 0.21 Currently circa 110 million Tonnes each year. THRFOR energy audit legislation, which limits CO2 emitted by burning fossil fuels to provide energy for buildings, is being introduced by Government. SO justification of the need for and limitation of the use of mechanical ventilation and refrigeration for control of the environment within buildings have become Government guide lines backed by the major institutions. YT the Design ngineer still has to comply with legislation which sets minimum fresh air supply rates and temperature limits for occupied spaces. lso clients who demand higher quality air and comfort conditions. XISTIG HVC SYSTS - "ROBS" TH SYSTS D T shown above were, in the main, developed at a time when buildings "leaked" air and had low resistance to heat and moisture transfer through their fabric. ny deficiencies were made up by oversizing heating, ventilating and air conditioning plant as illustrated. This meant that acceptable condition were achieved by designing for low mechanical ventilation levels and high recirculation rates. BT changes in building regulations have meant most buildings currently in use were either built or subsequently modified to minimise air leakage and heat transfer. FORTTY minimum air leakage plus low ventilation increases the level of noxious gases and odours in the space affecting the comfort of the occupants. HIDITY V also increases. which can cause discomfort, condensation and damage to the building fabric and contents. BCTRI multiply as well. causing higher incidence of respiratory disease. RCIRCTIO when combined with low ventilation rates, minimum air leakage and inadequate maintenance increases the spread of disease. noxious gases and odours. This is known as "sick building syndrome". ITR OVRHTIG occurs due to reduced heat flow through the structure combined with internal gains from lights. services. equipment. occupants and solar radiation. In addition to the above the building owner and operator still have to be satisfied with the cost of the environmental control systems. Then the cost of fuel, repairs, maintenance and redecoration have to be taken into consideration. Q: How can these costs be reduced, the problems overcome and the building owner and operator satisfied? : By utilising low energy sources.

3 OW RGY SORCS D THIR S The balloon, bar chart and description below illustrate how excellent controlled internal building conditions can be achieved utilising free or low energy sources and a very high efficiency extract to supply air energy transfer device. "FR" IR QITY COTRO. The CO2 limit for good indoor air quality is 800ppm while the average in outside air is 300ppm. This means that free, filtered outside air can be used to provide good air quality and help keep building occupants healthy. "FR" "RCYCD" HT. This free, filtered outside air can also be used for control of space conditions. It absorbs solar radiation previously absorbed by the building, plus heat from occupants, lights and Building Services. The heat contained within this air when extracted is a potential source of free heating for supply air. "FR" COOIG. The "inset" in the "balloon" shows that high limit area temperature for comfort with full fresh air supply is currently accepted as 27C. aximum outside air temperature in the K is below 27C for 98% of the time measured over 24 hours per day. Cooling is effected when supply air is at a lower temperature than the space or the building mass. The above three facts mean that outside daytime air is a potential source of free cooling of the occupied space for most of the year. lso outside night time air is almost invariably at a temperature which makes it suitable for free cooling of the building mass and the space. "FR" "RCYCD" COOIG. When the temperature of outside air rises above that of extract air, the extract air becomes a potential source of free cooling of supply air. "FR" DHIDIFICTIO. The "balloon" shows that the moisture content of outside air is almost always below that of a space which is allowed to "float" to 70% R.H. Dehumidification occurs if air is supplied at a humidity level below that of the occupied space. The above two facts mean that outside air is almost always a potential source of free dehumidification. "FR" "RCYCD" HIDIFICTIO. Building occupants and sometimes processes emit moisture. This is a potential source of free humidification. SSIV HTIG D TR VTITIO BIDIGS which utilise the above sources via passive heating and natural ventilation. usually involve extra capital expenditure to limit solar gain and to compensate for the lack of positive control of internal conditions. OWRD SYSTS which utilise the above sources and can supply 100% fresh air. reduce the risk of "sick building syndrome". CK OF COTRO still occurs, due to the arbitrary nature of wind force and direction and its strength compared to weak internal convective forces. OWRD SYSTS One disadvantage of these systems is that in winter outside air has first to be heated to space temperature, then heated more if it is to heat the space. OTHR ROBS are ingress of noise and dirt, conflict between occupants, security problems and reduction in working space due to large window or ventilation openings at low level. nother disadvantage of these systems is that to prevent eye, nose and throat problems and the build up of static electricity the air must also be humidified. Both processes use energy.

4 C RG VRY OW RGY ITS provide tempered air ventilation without mechanical heating or cooling and air conditioning with much reduced energy use RGRTOR C CK XTRCT 1 SHT OFF SHT DOW STDBY XTRCT CHGOVR DRS IRT RGRTOR C CK IRT OCCID BIDIG "FOTIG" WITHI ST BCK IITS ZRO CHI RGY S 2 RCIRCTIG 3 FR COOIG XTRCT XTRCT IRT CHRGD IRT COD STG 1 COOIG SIG "FR" OTSID IR OCCID - ST BCK RCYCIG ITR GIS D STORD RGY QISIG SC TRTRS WR - DOW RIOR TO OCCCY OR OCCID CO2 SSORS IDICTIG CCTB V 3W//S RGY S 100% FRSH IR D XTRCT "IGHT" COOIG OF BIDIG SS "DY" COOIG OF OCCID SC 100% DISCHRG OF HIDITY GI 4 CYCIG FOR RCOVRY HS 1 60 SCS CYCIG FOR TRD IR 60 SCS DRS CHG OVR VRY 3 HRS TO C C FCS 3W//S RGY S 5 CYCIG FOR RCOVRY HS 2 XTRCT XTRCT ITTIG BSORBIG BSORBIG ITTIG STG 1 HTIG - STG 2 COOIG 100% FRSH IR D XTRCT RCYCIG 85% TO 95% OF ITR GIS STORD S RGY I XTRCT IR RCYCIG 40% X. HIDITY GI DISCHRGIG 60% I. STG 1 HTIG - STG 2 COOIG WH CYCIG FOR RCOVRY TH DRS CYC BTW OSITIOS 4 D 5 T 60 SCOD ITRVS TH C CKS TK 10 CYCS - 10 ITS TO BCO FY CHRGD IF TH XTR COTROS SIG TO STO CYCIG TH DRS STY I TH OSITIO THY R I T THT TI

5 TH ID OW RGY OWRD SYST - DSCRITIO TH ID OWRD SYST is one which utilises the "free" or "recycled" sources previously described to produce acceptable internal conditions, retains control with varying internal needs and The 'pentagon' opposite show that C RG units utilise all the low energy sources previously described and perform all the functions required of an environmental control system by simply extracting and supplying air and moving two pairs of dampers. This rapid movement is effected by the RG unit internal controls and actuators. external influences, is simple in design and operation is relatively inexpensive to purchase, occupies a small amount of floor area, is usable on most sizes, type and complexity of building, integrates easily with other services and BS, C RG ITS The very high recovery efficiency of C RG units means that the basic unit can also be used as "add on" ventilation to existing buildings or systems without adding to, overloading or replacing existing heating plant, providing a small load margin exists. sychrometric charts and calculation sheets are available to prove this. reduces or eliminates the use of mechanical cooling, needs minimum maintenance and lasts the normal life of a modern building. This description fits C RG units. s a general rule if in winter the internal total gains always exceed the fabric losses by 10% of the fresh air load then no mechanical heating is needed, providing the normal rules regarding the introduction, distribution, movement and velocity of air in an occupied space are observed in order to avoid stagnation and or draughts. Only three 24V. DC switches in the remote control panel (by others) serving the area, need to be opened or closed to signal for the RG controls to perform any of the five functions shown. Separate shut off, discharge, bypass, recirculation or inlet dampers, atmospheric filters to protect the cells and frost heaters to protect the atmospheric filters plus associated pipework, insulation, wiring, controls and labour etc., are not necessary. lso the number and size of primary plant such as boilers, refrigeration equipment and their associated services as above, are reduced. These savings mean that RG units usually allow the use of a low energy system on projects without increased costs, compared to a traditional system. Some buildings, of course, are less thermally efficient and have less internal gains than others and in these cases:- "Top up" plant to adjust the condition of the supply air in order to maintain the occupied space within acceptable limits may be required in addition to the basic plant. Single zone top up heating, cooling, humidity and sound control plant can be built in. ulti zone plant can be installed remotely. But even if "top up" plant is required design calculations will show that almost invariably using C RG units will mean that total capital expenditure on the system is less and revenue expenditure on fuel, building fabric maintenance and plant maintenance are all much reduced. Reduced energy use assists in compliance with the government and major institutions' guide lines, limits pollution from greenhouse gas emissions, contributes to a cleaner environment and helps to reduce global warming.

6 C RG ITS ICTIOS C RG units can be used in almost all buildings, but are particularly suitable for those with high constant heat and or humidity gains, high occupation density and high ventilation needs such as:- Shops, malls, cinemas, sports halls, passenger waiting areas, baggage halls, lecture theatres, meeting rooms, restaurants, non critical hospital areas, offices, bakeries, clubs, public houses, schools, hotels, public buildings, casinos, animal houses, churches, theatres etc. The units integrate with displacement or induction systems, can be used in place of constant volume, or variable volume systems and can be added on to radiator, fan coil, cassette, split, suspended or free standing plant. ICTIOS-VRY OW RGY BIDIGS The C RG unit makes a major contribution to the savings made in very low energy buildings which use systems such as "TermoDeck" where 100% fresh air is blown to the space through ducts cast into high thermal inertia structural slabs, maintaining them at 19C - 21C and producing high air quality. t night slab temperature is adjusted by blowing outside air for "free" cooling or if conditions demand, recirculated air "trimmed" for temperature by plant contained within the C RG unit using off peak electricity, low emission gas for heating or mechanical refrigeration for cooling. OTIOS During the day the space temperature is controlled mainly by radiation to and from the slab. Fresh air "trimmed" for temperature by the RG unit, is supplied through the slabs, ensuring good air quality and limiting the temperature "swing" in the occupied space with minimal energy consumption. 1. tmosphere side attrs. 2. Regenerator cell packs. 3. Changeover dampers. 4. rimary dust filter. 5. Top up cooling coil. 6. ccess section. 7. Top up heater. 8. Top up humidifier. 9. Supply fan. 10. xtract fan. 11. Job side supply attr. 12. Job side extract attr. 13. Secondary dust filtration. 14. Fume filtration. 15. rimary extract filtration. 16. Secondary extract filtration. OT. Items shown outside the main air handling unit body may be unit or duct mounted as required. ir inlets should, of course, not be located where they can take in noxious gases or entrain exhaust air. If outside humidity rises above 95%, i.e. water droplets in suspension (mist or fog), the controls to the area served must signal for cycling to heat the air or for mechanical dehumidification to avoid condensation. This does not apply to TermoDeck systems or similar when the passage of air through the thermal mass of the slab (once this is "charged") will raise the air temperature and reduce humidity level. ir temperature limits are motor limits i.e. -40C to +40C except where blow through heaters are installed, then supply air temperature is limited only by heater capacity and safety. IITS I S Regenerators are not suitable for use where moisture recovery in excess of 40% is required i.e. swimming pools and process extract containing water droplets in suspension or in corrosive or toxic atmospheres. On damper changeover the exhaust air contained within the damper, the cell pack and the atmospheric duct reverses and becomes supply air. This gives cross flow approximating to 1% - 2%. Cross flow increases above this level in proportion to the increase in length of the atmosphere side ducting. ultiple units should not be served by common atmosphere side ducts as one unit may be pulling in fresh air at the same time as another unit is discharging extract air. The inertia due to the mass and the velocity of the air in the atmosphere side ducts added to the change from positive to negative pressure when the RG dampers reverse air direction causes duct wall deflection in these ducts. These ducts must therefore have low resistance, be of adequate thickness and have stiffening fitted in order to limit wall deflection and the possibility of sound generation. Should the supply air temperatures leaving the C RG damper section i.e. upstream of the supply fan fall to 2C the external controls should switch off both fans and signal that heating has failed.

7 OVR* FFICICY % v's VO m 3 /S OD FFICICY 30RG 30RG 30RG 30RG 50RG 50RG 50RG 50RG 50RG 50RG 50RG ~90.0% ~87.5% ~85.0% ~82.5% *FFICICIS QOTD R I HT RCOVRY OD D WH XTRCT VO = VO. S DSIG CK FOR CCTIOS WH XTRCT VO IS DIFFRT TO SO FOR COOIG RCOVRY D OISTR RCOVRY ODS ROGHIG I DISIOS mm S B HxW = = D OT: Items shown outside the main air handling unit body may be unit or duct mounted as required C C S S C C S S B S TTS = Telephone Technical Sales D F S Y T Y Q R H HIGHT W WIDTH XTRCT F RGRTOR B DRS D F < 3 BG D F < 9 BG Q HTR COI Q HTR C Q HTR GS TTS TTS TTS TTS TTS TTS TTS TTS TTS TTS TTS T COOR 6R T COOR 8R Y CCSS B BS D DISCHRG (x2) OCTIO F F S TTR ~R S TTR ~R S TTR ~R R HIDIFIR ROXIT XI WIGHTS Kg RG CS () RG DRS XTRCT F CCSS HTRCOI-HB HTR - GS TTS TTS TTS TTS TTS TTS TTS TTS TTS TTS TTS COOIG COI HIDIFIR TTS TTS TTS TTS TTS TTS TTS TTS TTS TTS TTS F+BG TTR ~R55 TTS TTS TTS TTS TTS TTS TTS TTS TTS TTS TTS TTR ~R45 TTS TTS TTS TTS TTS TTS TTS TTS TTS TTS TTS TTR ~R35 TTS TTS TTS TTS TTS TTS T TS TTS TTS TTS TTS

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