The DHP Series (Dehumidifier Heat Pipes™)
Heat pipes have been used successfully in a variety of HVAC design
applications over the past 27 years for passive dehumidification ranging from 2 ton
residential units to 230 ton commercial applications. HPT has wrap- around heat
pipes, controllable heat pipes, and heat recovery systems. Heat pipe products provide the
- Free precool and reheat
- No heat added to conditioned space
- Allows entire system to work more efficiently
- Increases latent capacity without additional energy
- Dehumidifies air entering the ductwork. Helps better meet the ASHRAE 62-1999 Standard.
- No moving parts to break down or wear out
- Often allows downsizing of entire HVAC systems
- Helps prevent IAQ problems associated with high
Passive humidity reduction with no moving parts, pumps or
additional energy input of any kind. Using the proven Dehumidifier Heat
Pipe Principle, the DHP typically precools incoming air by 8 to 13°F instantly,
allowing the cooling coil to meet the dewpoint faster and with greater efficiency.
Condensate removal by the cooling coil is greatly enhanced, often doubled by the heat
One of the most valuable aspects of heat pipe dehumidification is
the fact the process of reheat uses the same heat extracted in the precool section of the
heat pipe. Because heat is not added to the conditioned space, it does not have to be
removed by the cooling system, as with all active reheat methods such as electric strip
reheat or hot gas loops.
- May replace
electric strip reheat
- Passive reheat
does not add heat to the conditioned space
- Uses no pumps or
any other mechanical devices
- Operates without
interference of existing circuiting
- Low pressure drop
- May allow downsizing of
entire A/C system
Dehumidifier Heat Pipes in an HVAC System
Custom Wrap-Around Heat Pipes
Heat Pipes can be installed on almost any AC unit or air handler, whether at our factory or done on site.
U-Framed Heat Pipes
Ready to be placed as a fitted component in the air handle. This model often provides the simplest and most cost effective method of installation.
Controllable Wrap-Around Heat Pipes
Ideal for controlling supply air temperature.
Energy Recovery Heat Pipes Features
No energy input is required to operate the Heat Pipes. When two air streams pass through the Heat Pipes, (one air stream at one end, and another air stream at the other end), the temperature difference between the two air streams activates the Heat Pipes and causes them to exchange heat by “Heat Pipe action”. Heat Pipe action is a much more powerful heat transfer mechanism than convection flow. Heat Pipe action utilizes the heat capacity available when the working fluid changes phases, from a liquid to a vapor and back again.
There is nothing in the Heat Pipes to wear out! The Heat Pipes are passive. They have no moving parts (unless they come equipped with a bypass damper.) To guard against corrosion, the Heat Pipes can be ordered with a baked epoxy coating or other protective coating. The Heat Pipes are fabricated with a multitude of charged circuits. Under normal operations, there is no reason for these ever to leak. If some inadvertent mechanical damage were to occur on one circuit to cause it to leak, there would be little effect on performance even if the leak was not repaired. Furthermore, because the tubes in Heat Pipe Technology Heat Pipes are copper, leaks can be fixed. Most other Heat Recovery Heat Pipes are fabricated with aluminum tubes which are very difficult to repair.
Isolated Air Streams
Dividing plates to separate the two air streams are an integral part of Heat Pipe Technology Heat
Recovery Heat Pipes. The copper tubes carrying the Heat Pipe working fluid are
expanded into the mating holes in the dividing plates assuring an excellent seal to
prevent cross contamination.
Since the Heat Pipes have no moving parts (apart from any dampers), the only maintenance recommended is periodic cleaning. A coil cleaner may be applied for this purpose just as for any cooling coil.
Heat Recovery Heat Pipes from Heat Pipe Technology take up much less space than other heat recovery schemes. They are also generally more compact than other heat pipes. A six-row heat recovery heat pipe can be fabricated with a thickness of as little as 8 inches.
Summer and Winter
The same Heat Pipe can be used for both summer cooling and winter heat recovery without any changeover mechanism. The temperature difference between the air streams activates the energy recovery.
Three Configurations of Energy Recovery Heat Pipes:
A. Over-and-under horizontal
air streams with Heat Pipes in a vertical plane
B. Side-by-side vertical air
streams with Heat Pipes in a horizontal plane
C. Side-by-side horizontal
air streams with Heat Pipes in a vertical plane