Bob and Tim were on their way to a no cooling call at a residence. They were pretty sure that it was a low refrigerant call. Bob said, “I hope that we can put the last lesson into practical practice. We have gone to a great deal of trouble to understand superheat.”
Bob and Tim were in the company conference room where Bob is set to give Tim some extra training at Tim’s suggestion. Bob said, “Tim, you asked for more explanation of what superheat is. This is not a very simple topic. It will take a couple of meetings to go into detail about it.”
AHR Expo attendees who stop by the Sporlan booth (#1533) for a 10-Minute Tech Talk are being entered into a drawing for an iPad. Tech Talks include: Secondary Glycol System Control: A Better Solution, Advances in Transcritical CO2 Flow Controls, and Turnkey Superheat Control in Heat Pump and A/C Systems.
With four ports and a built-in vacuum gauge on the SMAN4 digital manifold, users can evacuate a system, pull a vacuum, add refrigerant, and dial in the charge without unhooking their manifold. There are three standard ¼-inch ports and one beefy 3/8-inch port with the bore in the manifold being 3/8 inch throughout.
There will always be a time when the evaporator sees a light load and the TXV may lose control of its evaporator superheat due to limitations of the valve and to system instability. What do you do then?
Series HSV electric expansion valves offers precise superheat control. The valves feature a direct drive linear actuator using a hybrid step motor that provides increased power for its size, and eliminates unnecessary parts and their associated failure potential, the company said.
While my last series of columns explored liquid subcooling in a refrigeration system, this article will compare subcooling amounts in a refrigeration system incorporating an overcharge of refrigerant, a dirty condenser, and air in the system.
The amount of condenser subcooling needed is system dependent. The more pressure drops — friction and static — associated with the lines and accessories that carry the liquid in the system, the more need there will be for liquid subcooling to prevent liquid line flash gas.
Condenser subcooling ensures that there is a liquid seal at the condenser’s bottom so the liquid line or receiver will not be fed with vapors. This condition prevents any noncondensables, like refrigerant vapor or air, from leaving the condenser’s bottom and entering the receiver or liquid line.