Articles by Dave Demma

The Electric Suction Line Regulator

February 2, 2009
In the electric suction line regulator, the step motor assembly is connected to the main modulating piston through a gear reduction drive. As the motor rotates in one direction or the other, it will drive the main piston open or closed. These valves are commonly referred to as electric EPR, EEPR, or electric evaporator pressure regulator valves.
Read More

The Untypical Refrigeration System

January 12, 2009
For the last five years, the supermarket industry has undergone a gradual shift in thinking regarding the preferred method for controlling evaporator discharge air temperature. You might call it an untypical … and more modern approach.
Read More

Heat Reclaim Service Issues

May 28, 2007
This is the final in a three-part series that began in the March 12 issue with a discussion of heat reclaim in three-way valve operation and continued with heat reclaim in series and parallel in the March 26 issue.
Read More

Heat Reclaim in Series and Parallel

March 26, 2007
Heat reclaim can be accomplished with either a series or parallel method. In the series approach, when a finned tube heat exchanger is used it is properly termed a heat reclaim coil.
Read More

Heat Reclaim with Three-Way Valves

March 12, 2007
If the goal of the vapor-compression cycle is to convert the refrigerant to the state necessary to be a useful heat transfer medium (the evaporation stage), the other three stages can be looked upon as a means to an end. However, they perform no useful function other than preparing the refrigerant in its journey of transformation into something useful. Or do they?
Read More

Multimedia

Videos

Image Galleries

2014 ACI Home Performance Conference

The 2014 ACI National Home Performance Conference & Trade Show was held in Detroit.

Podcasts

Jeff Hutchinson, Energy Solutions Manager for mechanical contractor Bruner Corp., talks about the ductless market and how it can be profitable for a commercial contractor.

More Podcasts

ACHRNEWS

NEWS 07-21-14 cover

2014 July 21

Check out the weekly edition of The NEWS today!

Table Of Contents Subscribe

R-22 PHASEOUT POLL

Some in the industry are calling for the EPA to halt production of R-22 as of 2015. What do you think?
View Results Poll Archive

HVACR INDUSTRY STORE

plumbing-hvac.gif
2014 National Plumbing & HVAC Estimator

Every plumbing and HVAC estimator can use the cost estimates in this practical manual!

More Products

Clear Seas Research

 

Clear Seas ResearchWith access to over one million professionals and more than 60 industry-specific publications, Clear Seas Research offers relevant insights from those who know your industry best. Let us customize a market research solution that exceeds your marketing goals.

DON'T MISS A THING

Magazine image
 
Register today for complete access to ACHRNews.com. Get full access to the latest features, Extra Edition, and more.

STAY CONNECTED

facebook icontwitter iconyoutube iconLinkedIn i con