Install Manual

04/03/2009 15 EI204
10. System temperature response – the overall temperature rise (both sides of HeatChoice) must be within the
maximum specification, see "Specification Chart". If any portion of the plenum (above elements) is
operating with an air temperature greater than 125°F, element life will be shortened.
- CFM CALCULATIONS, THIS HEATCHOICE
- By measuring the temperature rise
across the HeatChoice, the actual CFM can be quite accurately determined. If you are having
difficulty sustaining hi-limit operation, it may be a good idea to calculate the CFM according to this
formula. To arrive at a stable output temperature, you can turn off CB #2 and operate only as stage
one. This will allow you to verify or calculate the CFM without reaching hi-limit cycling. The
accuracy of this formula will depend upon uniform and average temperature rise plenum
thermometer readings and the accuracy of both the clamp-on amp meter and AC voltmeter. NOTE:
The volts x amps x 3.4 value is the same as Btuh output.
Volts x Amps x 3.4
CFM =
Temperature Rise x 1.08
- CALCULATED CFM, OIL/GAS FURNACE
- By measuring the temperature rise across
the existing furnace, the CFM can be approximated. The accuracy of this formula will depend upon
the estimated or determined Btuh output (actual heat energy across the furnace). You cannot use
nameplate Btuh values. You must use a realistic estimated or measured true OUTPUT Btuh.
Btuh (output)
CFM =
Temperature Rise x 1.08
11. Special stand-by furnace and special plenum width conditions – as we continue gathering installation
experience, we are seeing several over temperature situations reoccurring. The intent of this paragraph is to
provide additional help for four specific plenum conditions:
a. Large burner pot oil furnace with the HeatChoice installed less than about 6" from the top of the
heat exchanger/fire pot.
- Install from either the back or front (inline with the flue or burner)
b. HeatChoice installed from either side of an oil furnace.
- Locate as high as possible above the oil furnace, but realizing elements need to be inline
or below take off ducts
c. Plenums width between 19" and 20½"" without the use of side deflectors.
- Add deflectors per drawing EH101, C-1
d. HeatChoice installed above an A-coil where the HeatChoice sits directly on top of the A-coil
without side deflectors.
- Add deflectors per drawing EH101, C-1