Introduction
In 1993, two-stage infra-red heating was developed and introduced  to the market in 1993.  To prepare another objective analysis of two-stage versus single stage infra-red heating, this time at a typical poultry facility, an independent research firm (RDM Engineering) was engaged in 1995.

Compared with a competitor's single stage heating system on the "control" side, the Re-Verber-Ray two-stage infra-red heating system achieved an average 33.5 percent in energy savings during Crops 1 and 2 and an average 51.7 in energy savings during Crops 3 ,4 and 5.

The engineering design of the two-stage HL Series encompasses a "low fire" mode for moderately cold days and a "high low" mode for the coldest Winter days when 100 percent of the designed heating capacity is actually required.

This innovative concept is based on a detailed analysis of weather data over 25 years that clearly showed typical industrial and commercial buildings only require 100 percent of there designed heating capacity (the "high fire mode) 5.6 to 9.7 percent of the time- depending on the geographic location. For the remaining part of the heating season, a "low fire" mode - operating at only 70 percent of the designed heating capacity - is all that is required. Based on this and related data the HL Series was developed.

The Test Site
The test site was carefully selected to reflect a typical poultry facility where day old chicks are brought in and raised for eight or nine weeks. The three storey structure was 300 feet by 56 feet with eight foot ceilings. During the test period the ground (first) floor was divided in half creating two equal sized "rooms". The building's geographic orientation is linear east to west. The east room was heated by an existing system of four 85,000 BTU/h single stage infra-red heaters. The west room of the building was retrofitted with four Re-Verber-Ray HL Series two-stage infra-red heaters (Model HL-30-75N), each having 75,000 BTU/h on "high fire" mode and 52,500 BTU/h on "low fire" mode.

 

The significant reduction in the number of on-off cycles with Re-Verber-Ray two-stage technology resulted in increased energy savings, improved comfort and extended product life at this typical Canadian poultry facility - when compared with a competitor's single stage infra-red heating system.

Part way through the test there was already a significant advantage shown with two-stage technology. Evan with the prevailing winter winds from the west, it was proven that for Re- Verber-Ray units were not required to heat the west room. As a result, after the second Crop, one Model HL-30-75N unit was removed leaving three two-stage units in the west room and four single stage units in the room on the east side.

It is important to know that each room had its own feed, water and ventilation system throughout the test period. Other parameters for the building include steel cladding and wood frame construction with R20 (RSI 2.9) insulation.

Test Procedure and Monitoring
The east room served as the "control" using existing single stage infra-red heaters. The west side of the building utilized Re-Verber-Ray HL Series two-stage infra red heaters. Both rooms were loaded with the same number of birds at the same time

The data was collected by: (1) Hour meters to record the actual "on time" for the single stage and two-stage infra-red heaters; (2) Event counters to record the number of on-off cycles for each time period; (3) Equipment to record temperature and humidity at five minute intervals; (4) Gas meters to record the daily consumption for the east room and the west room on the first floor of the building and; (5) Feed conversion and other crop performance data supplied by farm management.

The Results

Conclusions
1. Average daily on-off cycles were reduced from 85 cycles during Crops 1 and 2 with the original Re-Verber-Ray four heater design to only 26 cycles during Crops 3 ,4 and 5 with the three heater design. This significant reduction in the number of on-off cycles with Re-Verber-Ray two-stage technology resulted in increased energy savings, improved comfort and extended product life.
2. Compared with competitor's single stage heating system on the "control" side, the two-stage infra-red heating system achieved an average 33.5 percent in energy savings during Crops 1 and 2 and an average 51.7 in energy savings during Crops 3, 4 and 5.
3. The greater overall efficiency of the Re-Verber-Ray HL Series infra-red heating system results in a cleaner environment.
4. With two-stage infra-red heating full heat output is available on demand for particularly cold days and new crop start-ups.

RDM Engineering
Over the past 12 years Guelph, Ontario based Ronald D. MacDonald and RDM Engineering have researched and produced a number of scientific, technical and information papers on the subject of energy efficiency, as well as tested and reported on other energy matters for a wide variety of clients. Serving as an Energy Advisor and Energy Specialist to government, major utilities and private sector clients, Mr. MacDonald and RDM Engineering remain actively involved in a broad spectrum of energy matters, including their recent testing and reporting on the Re-Verber-Ray two-stage, high-low HL Series detailed in this Technical Report.