Purge Your Hoses

July 10, 2017

The title says it all. It should be one of the first things you learn when you started. However, I have seen a lot of experienced techs who seldom (if ever) do it.

When connecting to a tank, purge your hose by cracking the center connection at the manifold for a second.

When connecting to a system, crack each connector for a second and then tighten. (Unless you are using ball valves or low loss of the same refrigerant type.)

Low loss brings up a different subject. If you are using them, you need to make sure not to switch between refrigerants without recovering all the refrigerant from your gauges.

Both air and incorrect refrigerant are not acceptable to add to the system, even in small quantities.

—Bryan

#purge

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Chris Hughes and Steve Rogers from The Energy Conservatory discuss TEC’s TrueFlow technology and its crucial role in predicting airflow issues in the sales process, particularly for heat pump retrofits. They explain how the TrueFlow app helps contractors accurately measure both static pressure and airflow in existing systems, enabling them to predict whether proposed equipment changes will work effectively. This is especially vital when considering the growing trend of replacing gas furnaces with heat pumps, as the airflow requirements can differ significantly.

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Key Topics Covered:

TrueFlow technology and its role in system forecasting
Fan Law 2 and its impact on static pressure when changing airflow
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Dual fuel systems as a solution for cold climates
The relationship between airflow and static pressure
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The importance of envelope assessment
Methods for reducing system loads
Proper duct sizing and modification strategies
The role of proper filter sizing and selection
The benefits of flat-rate pricing for duct modifications
Training resources and support available for TrueFlow users

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Comments

John @bryanorr

Is purging necessary if you are simply checking pressure and not opening to the manifold? I’ve been told it is not and that the air in your hoses cannot flow out of your hose and mix with the refrigerant in the system.

4/4/23 at 06:51 PM

Roman Baugh @roman-baughkalosflorida-com

The concern is less about the mixing of air (which is possible if you accidently open your high side to low side) and more so for the amount of moisture that is present in the air that is trapped in your hoses. Remember that moisture migrates and POE oil is hydroscopic. Reducing the risks (purging your hoses) of moisture contamination within the system should always be the standard practice.

4/10/23 at 06:41 PM