You are here » » » Best Management Practice #10: Cooling Tower Management Best Management Practice #10: Cooling Tower ManagementIn 2007, the university carried out an energy survey in the building to assess performance and highlight areas where improvements could be made to bring down energy consumption and provide better conditions for occupants. This resulted in adjustments being made to the building’s Trend BMS, which had been set to operate the HVAC services from 4:00 am to 10:00pm seven days a week. These times were reduced significantly and, together with changes made to a number of setpoints, led to energy consumption cuts of around 8% for electricity and almost 50% for gas. However, the adjustments highlighted a number of operational issues that had previously been disguised by the long operating hours and it was decided to bring in Trend Control Systems to undertake an energy audit of the building and its BMS. This was carried out in November 2007. The building is heated in a number of ways depending on the area.

Most heating is provided by tempered air from seven air handling units (AHUs). There are also perimeter heating on each floor and a mixture of wet and electric radiators in the stairwells, lift lobbies and basement corridors. Some classrooms have fan convectors. The main entrance foyer has underfloor heating and cooling. The low loss header from the boilers feeds five secondary heating circuits, three being constant temperature (CT) and two variable temperature (VT). The CT circuits are for the basement and rooftop AHUs and the domestic hot water service, whilst the VT circuits are for the perimeter heating, radiators and underfloor heating. The report by Trend recommended various opportunities for energy savings.  It noted that several floors were always too hot and there was constant adjustment of on/off times and setpoints in an attempt to overcome this issue. Trend examined the system settings (on/off times and setpoints) and recommended that they be reset to a base setting of standard opening times and 21°C. 

Then, if specific areas were revealed as being too hot or cold, further tests should be carried out. It was also observed that there was no significant ‘dead band’ between heating and cooling. When an AHU operated close to the required supply air setpoint there was significant temperature fluctuation as the heating and cooling cycled on and off.  Trend’s report pointed out that it was not necessary to have close control of supply temperature with this type of system. Its recommended solution was to provide a fairly wide dead band between heating and cooling. Operation of the thermal wheels to take priority over use of the heater batteries in order to maximise heat recovery. The proposed changes were among many improvements subsequently made by Trend and the university’s own personnel, the work being completed in January 2009. The resultant reduction in electricity consumption averaged 8.2% (281,000 kWh annual), with savings of 18.5 – 19.8% respectively in the critical months of January and February.

The reduction in gas consumption averaged 10.3% (143,000 kWh annual) with the greatest savings being achieved in July (59.3%) and August (48.3%).used air conditioning unit for sale The averaged annual savings in energy costs due to the university’s adjustments totalled £81,812 and the savings attributable to Trend have so far reached £60,839 (adjusted to delivered energy costs in November 2009).how does hvac work in a house “We have been delighted by the results of implementing these measures,” said Stephen McKinnell, Energy and Environmental Manager in City University London’s Property and Facilities Department. how long should an outside ac unit last“It shows that bringing in experts to look at operating strategies, rather than continuously adjusting setpoints, can result in huge improvements.

The investments have paid for themselves in a matter of months and the number of complaints has greatly reduced.” The university has recently been trialling a new control regime for some of the dampers that serve a mixture of classrooms and common areas; the aim is to achieve better temperatures and to zone the building more effectively.  This is expected to provide additional savings and, if successful, will be rolled out throughout the building. The energy saving initiatives carried out at the Cass Business School have involved both Trend Field Services and the company’s Energy and Support Solutions team. Trend partners ST Controls and Energy Efficient Controls have also worked closely with the university, having installed Trend controls in a number of other buildings on the campus.The list of abbreviations used in a set of engineering drawings varies from office to office.  Be sure to check the front section of the drawing set for the abbreviations used within. AAir or Compressed Air

CFMCubic Feet per Minute CTBDCooling Tower Blow Down EAEach or Exhaust Air EAHUExhaust Air Handling Unit FAFree Area or Fire Alarm FDFloor Drain, Fire Damper, or Fire Department HPHorsepower or High Point HZHertz (Cycles per Second) NCNoise Criteria or Normally Closed PCFPounds per Cubic Foot PSIPounds per Square Inch PSIAPounds per Square Inch - Absolute PSIDPounds per Square Inch - Differential PSIGPounds per Square Inch - Gauge SDSmoke Detector or Smoke Damper SFDCombination Smoke / Fire Damper TEFCTotally Enclosed Fan Cooled TON12,000 BTUH (Cooling Capacity) HomeSpec Certified Inspections, Inc. Providing inspections throughout Southwest Florida. Call or text: (941) 270-1349 Fla License # HI959 Need a home inspection in Maryland? listing of Maryland certified home inspectors. find a home inspector anywhere in the world with our inspection Re: Sweating air handler

Dave Fetty Certified Professional Inspector Florida Home Inspection And Property Services LLC Naples, Marco Island, Ft. Myers, Bonita Springs, Estero, Cape Coral ITC/FLIR Level I Building Investigation Thermographer FL Certified Building Contractor CBC034303 FL Certified Home Inspector HI 391 FL Certified Mold Assessor MRSA 589 Yea, I explained the unit might need more insulation but it was only an educated guess and to get a HVAC tech to confirm and or recommend the fix. Originally Posted by tmiller2 I can not see from here but if you think about what you are asking (what causes condensation) that is your answer the air temp is lowered to dew point and if it is making contact with the outer surface of the AHU it will condense out. You did not say if the unit was a down flow, a upflow or horizontal flow just that it was hanging from the ceiling. It would ber most helpful to know what area of the furnace has the condensation the coil box, I can not image the return air section having any condensation the temp is to high

Master HVAC Mechanic Retired Level III Thermographer # 8486 Infraspection Institute CMI Certified Master Inspector Moisture Intrusion Expert Witness Serving Gainesville Florida and surrounding areas.Deus solus me iudicare potest Originally Posted by frotteHowever if they restricted the air over the coils as in blocking of some of the registers and or bad or clogged filters that will freeze it up as well. Justin, that just makes too much sense. and your post did not include the phase of the moon! "working together to get-IR-done" Chris Walsh David A. Andersen & Associates Clarksville - Nashville Home Inspector Lic#40 ITC Level III Thermographer Cert#1958 Building Science Thermographer Cert#33784 HVAC Certification EPA Cert#2046620 Were your clients with you during their inspection? I just find it odd people, knowing how long you examined systems, the conditions of the weather outdoors, and everything else short term - would call you back, wanting what exactly?