TXV Retrofit Kits Save Energy

August 3, 2009
It is being reported that removing a fixed orifice type metering device and installing a thermostatic expansion valve can increase the SEER rating of equipment.

With our industry’s ever-increasing demand to improve energy efficiency, we should consistently be looking for ways to improve the performance of the air conditioning equipment we service. The Department of Energy’s (DOE) goal is to save 29 billion kilowatt-hours of energy by the year 2030.

To help reach this aggressive goal, in 2006 the DOE raised the minimum SEER rating from 10 to 13 SEER for new residential air conditioners. This was a costly undertaking for most equipment manufacturers who in turn passed this cost on to the end user.

With our economy in the condition it is, the average consumer might have second thoughts when informed that his or her equipment should be replaced. Servicing and repairing equipment can be a more practical option than complete equipment replacement.

Many residential and light commercial equipment owners will be looking for the edge to help them save a few dollars when it comes to keeping their heating and cooling equipment operating as efficiently as possible. If they are informed about the opportunity to increase the energy efficiency of their equipment, while making the necessary repairs, I’m sure you would have their attention. Higher efficiency usually translates to lower utility costs.

This is where a new thermostatic expansion valve (the Danfoss Universal TR 6) can help. The manufacturer claims that when removing a fixed-orifice-type metering device and installing a thermostatic expansion valve (TXV), you can increase the SEER rating of the equipment. This claim is substantiated by the fact that a system using a fixed orifice, refrigerant flow remains the same, regardless of load demand on the system. By installing a TXV, you can match the cooling load of a system, as the load changes throughout a cycle. This in turn will increase the efficiency of the equipment.

Independent testing on three different types of residential equipment has shown a 15-26 percent increase in efficiency just by replacing the fixed-orifice-metering device to the new TXV. No other work was done to this equipment to increase the EER.

We at ICOR International also tested the valve on two residential units with HFC-422B, our HCFC-22 replacement. We determined that the compressor compression ratio improved, which will also improve efficiency.

These valves are available for R-22 up to 6-ton units and HFC-410A up to 7-ton units. They are also available for heat pumps. The kits are supplied with a variety of fittings to adapt to different styles of fixed orifice piping designs, which allows for a fairly simple install.

There is also a similar conversion kit from Sporlan, just so you’ll know there is a variety to choose from. We have not had the opportunity to test any of the Sporlan kits at this time but I’m sure they will achieve the same results.

So, now you have the opportunity to improve older 10 SEER equipment efficiency and retrofit to an HFC ozone-friendly refrigerant, all in the same service appointment.

Publication date: 08/03/2009