Screen reader users, click here to load entire articleThis page uses JavaScript to progressively load the article content as a user scrolls. Screen reader users, click the load entire article button to bypass dynamically loaded article content. Volume 35, Issue 12, December 2010, Pages 4592–4599The 3rd International Conference on Sustainable Energy and Environmental Protection, SEEP 2009Edited By Abdul Ghani Olabi Experimental investigation of wraparound loop heat pipe heat exchanger used in energy efficient air handling unitsa b Received 13 November 2009, Revised 30 March 2010, Accepted 31 March 2010, Available online 10 May 2010Building legislation along with environmental and comfort concerns are increasingly driving designers of building services and air conditioning equipment towards more energy efficient solutions. Heat pipe technology is emerging as a viable, efficient and environmentally-sound technology for applications in efficient air handling unit designs. In this paper, an experimental investigation on the thermal performance of an air-to-air heat exchanger, which utilises heat pipe technology, will be presented.

The heat exchanger consisted of 7 loop heat pipes with finned evaporator and condenser sections. The heat exchanger was fully instrumented to test for the effect of the variation of heat load and the air velocity, through the heat exchanger, on the overall thermal resistance of the loops. The values of the effectiveness of the heat pipe heat exchanger are shown to vary with the air velocity as expected but the results also allow the prediction of effectiveness variation with the heat load and operating temperature (previously assumed to be constant). The results allow an interpretation of the overall thermal performance of each loop heat pipe as a function of the load and air velocity. The paper concludes with a theoretical analysis of the energy savings that would be expected when utilising the technology in a representative application.Keywords; ; ; ; Copyright © 2010 Elsevier Ltd. I have a relatively old air handler that has worked fine for many years. Just recently, it started leaking water everywhere, and it seems to be seeping from inside the base of the air handler itself (as opposed to a leaking pipe, or something outside the unit).

The condensation line that leads outside the house has not had water running through it recently, so that is clearly related. I assume it is backing up somewhere.window ac unit cooling capacity But when I pour water into the clean-out, it goes right into the condensation line and outside the house, so I feel like the blockage must be prior to the clean-out. best apartment hvac unitsThe pipes are glued together, so I'm not able to take them apart, but there is only a few inches of pipe between the air handler and the clean-out, and it doesn't seem to be blocked in there.how to replace a fan motor in an ac unit Could this be a problem inside the unit itself? Is this something that I could attempt to fix myself? I am moderately handy, but don't know a whole lot about plumbing or HVAC.

I would call an HVAC company, but they are all booked several days or weeks out, and I am putting my house on the market tomorrow. I'd prefer to get this fixed before people start coming to look at the house. I tried opening the panel, but the drain pipe is holding it in. I tried loosening the drain pipe screw, but it won't budge. Update - Today, the weather was nice, so we turned off the A/C and opened the windows. Periodically throughout the day, I would hear the pump running, pushing water out of the condensation line. So I am assuming that there is a blockage somewhere in the air handler that lets just a small amount of water come through. So when everything is off, the backup of water slowly comes through and gets pumped out, but when it's on, there's just too much water, and it ends up spilling out. Any help would be appreciated. The Tee was left open as a means of a clean out. Start by using a shop-vac on that Tee and hold your finger over the other end, in the pump (you may have to get the pump out of the way).

Followed with another vacuuming. Ideally the first go sucks it out; you don't want to just push the clog inside. If it still leaks after all that, you may have a cracked pan.Browse other questions tagged hvac leak condensation or ask your own question.HVAC: Equations, Data, and Rules of Thumb, Second Edition There is a newer edition of this item. HVAC Equations, Data, and Rules of Thumb, Third Edition Arthur A. Bell Jr Fast solutions to specific problems HVAC personnel face every day. Written by a veteran HVAC designer, this task simplifying guide puts essential HVAC answers at your fingertips. Featuring 200-plus equations, completely updated codes and standards, more than 350 rules of thumb, and other essential data, this is the most complete HVAC reference available. Title: HVAC: Equations, Data, and Rules of Thumb, Second EditionPublisher: McGraw-Hill: New York, Chicago, San Francisco, Lisbon, London, Madrid, Mexico City, Milan, New Delhi, San Juan, Seoul, Singapore, Sydney, TorontoCopyright / Pub.

Date: 2008, 2000 The McGraw-Hill Companies, Inc.ISBN: 9780071482424Authors:Arthur A. Bell Jr is the author of this McGraw-Hill Professional publication. Login for UK Access Management Federation Institutions (Shibboleth)Air conditioning systems for buildings may rely on either a liquid, such as water, or air as a distributionConditioned air is typically distributed by duct and chilled water is distributed by pipe. Chilled water distribution systems are most commonly found for air conditioning large buildings. The reason for this is it is more efficient and economical to transfer (or remove) heat by water ratherThis is due to the higher heat capacity water has and the fact pipes that carry water are smaller and take up far less space. A third advantage of chilled water is flexibility for zone control. The chilled water will eventually cool air locally by convection, through air handling units or fan coilAir handling units are typically larger than fan coil units and have more sophisticated zone

Air handling units are often found in large office buildings, hospitals, etc. are typically smaller and serve smaller spaces. These units are typically controlled by simple thermostats and are often found in residential buildings, hotels, etc. Chilled water is typically distributed by pipe from a system that features cooling towers and chillers. The operation of chillers and cooling towers is a subject for future discussion. A system that is similar to a chilled water system is a water source heat pump system. Water source heat pump systems would also typically have a cooling tower, but no chiller. Chilled water distribution systems can use the same pipe system as the hot water heating systems. A water source heat pump system would also provide heat, utilizing the same water loop. When utilizing chilled water and air handlers or fan coils to cool (and heat with hot water) a building, there is a distinction between two-pipe and four-pipe systems.

In a two-pipe system there is only one water loop and thus two pipes at each air handler or fan coil (supply pipe and return pipe). So, the building can either be in cooling mode or heating mode. In these situations, there is often a ‘switch over date’ where the chiller is shut down for the season and the boiler is started,After the ‘switch over date’, if there is a heat wave, it will not likely be possible to cool the building because the chiller has been shut down and the water loop has been directed throughControl valves are used to switch the system from heating to cooling and back. In a four-pipe system, there are two separate water loops used for heated water and chilled water. This allows both systems to operate simultaneously for those times when some parts of the building need to be heated and other parts need to be cooled. Additionally, there is no seasonal switchIt is easier to switch between heating and cooling when the outdoor temperature

The four pipe systems are obviously more expensive because of the additional water loop, controls and more expensive coils in the air handlers. Heat pumps may be either liquid or air source. Liquid or water source heat pump systems typically consist of various smaller units above the ceiling tile or in closets on each floor of a high-rise building. In a liquid source heat pump system there is a single water loop. When air conditioning, the water loop is gathering heat from the refrigerant at the heat pumps. This takes place in the heat pump’s condensing coil. The water loop must then reject the heat; this is typically accomplished through a cooling tower outside the building. When heating, the water loop is providing heat to the refrigerant at the heat pumps. must then gather more heat; this is typically accomplished through a boiler inside the building. In some heat pump systems, heat is moved from one side of the building to the other: the heat that