thermal efficiency of old boilers

Ted_4

> What is the easiest way to check thermal <BR>
> efficiency of existing old boilers. I understand <BR>
> the basics but trying to figure the most accurate <BR>
> but not overkill way of doing it. Thanks in <BR>
> advance. <BR>
<BR>

tim smith

thermal efficiency of old boilers??

What is the easiest way to check thermal efficiency of existing old boilers. I understand the basics but trying to figure the most accurate but not overkill way of doing it. Thanks in advance.

Ted_4

Efficiency Test

If by "thermal efficiency" you mean combustion efficiency, the easiest way is with a digital combustion analyzer such as a Bacharach Fyrite Pro. This tester (or the older manual types)will give you an idea of how much of the heat from the fuel burned is going up the stack, and how much is being made into useful heat.

Finding out the "seasonal efficiency" (what percentage of the heat produced is actually making it to the living space) is a lot trickier, and depends on where the boiler is located, the amount of jacket insulation, the amount of burner run-time, etc.

We find that the perfomance of older boilers can often be improved noticably by cleaning the heat exchanger,improving the burner or burner tuning, and reducing the firing rate. All these improvements are immediately shown by combustion analysis.

tim smith

efficiency

Ted, thanks for the reply, combustion efficiency is one we do all the time but thermal, or in your term seasonal is the one I am trying to figure the best way to measure. Thanks again, Tim.

eleft_4

This should be a good starting point.

http://www.foam-tech.com/testing/testing.htm
(copy & paste)

al

Constantin

Makes you wish...

... you could have two strap-on flow meters (ultrasonic), two thermometers, to figure out the flow of BTU's into and out of the boiler. Monitor the intake of gas or oil, then figure out the difference.

The flue gas approach is cheaper and easier, no question. However, a actual flow analysis would settle once and for all what BTUs are being sent into the building vs. being lost on standby, etc.

tim smith

flow analysis and temps

I have the ashrae calculations to figure the thermal efficiency. Hardest part is getting ahold of the ultrasonic meters for flow, a costly proposition. Can't justify buying one. May have a company I know come in with his test and balance equipment to do this. Still $$ but may be worth it on some jobs. Thanks for the replies all. Tim