We have been asked a lot about the difference between the Straight Heat Pipe and Wrap-around (U-shaped) Heat Pipe, so there it is.
Wrap-around (U-shaped) Heat Pipes are primarily used for energy saving and humidity control. They provide a very reliable and energy saving alternative to electric heaters or other forms of reheating.
There are typically two methods to use them:
- In fresh air Precool AHU: With this method, heat pipe facilitates proper cooling of fresh air and usually the fresh air supply can be maintained around 20 Deg.C, 50% RH. In this way, fresh air mixing with return air becomes a source of ‘dehumidification’ rather than being a moisture load.
- Used in main AHU: this method is used when there is a need to regulate the reheat and RH levels are critical to be maintained like in Operation Theaters, Labs, etc.
Main features of Wrap Around Heat Pipes are as below:
- A device installed in an AHU for transferring heat efficiently between two locations by using the evaporation and condensation of a fluid.
- Improves air quality, prevents mold and fungus growth.
- Reduces humidity to 50 -55% RH.
- Zero operating cost, capital cost savings, installation space savings, payback period usually less than a year.
- No electrical connection needed, required no external energy to operate.
- Completely silent operation, no moving parts.
- Long service life – no wear and tear, nothing to replace; Virtually maintenance free.
- Easy to regulate reheat with thermostat control.
- Easy points in Green Rating Systems (GBI, LEED BCI, etc).
Straight Heat Pipes are an exhaust recovery device. Two air streams pass through two sections of heat pipe – One is fresh air intake and the other is the outgoing exhaust air. Heat pipe captures cooling from fresh air and uses it to pre-cool the fresh air, hence saving energy on further cooling of air.
- Heat Pipes have no moving parts and save energy without any maintenance requirement.
- Straight heat pipes are best when there is a need to have complete separation of exhaust and fresh air so that there is 100% guarantee that there will not be a chance of contamination of fresh air with exhaust.
- These heat pipes primarily recover sensible heat.