Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.
Calculating efficiency of older boilers

Jesse_3
Member Posts: 3
I am trying to find some information on calculating the efficiency of older style gas hot water boilers. I was wondering if there are a set of equations or some software that would be helpful. Thanks.
0
Comments
-
easy on paper
clock the gas meter.
measure delta T water temp. in/out of boiler
measure flow rate of water.in/out of boiler
delt T x 8.33 x gallons flow = btu's boiler output
meter clocking will give you btu's into the boiler0 -
don't forget you have to multiply gpm times 60 minutes for the BTUH.0 -
estimating efficiency
If you don't have access to temp in and temp out, or flow rate in & flow rate out, one way to *estimate* efficiency of an old boiler is to take a combustion efficiency test result and multiply by 0.85. So if a technician performs a combustion efficiency test and says the boiler has a combustion efficiency of 84%, then the overall efficiency (similar to AFUE) is about 71% (85% x 0.85). This would account for off-cycle losses, and so forth. Of course, this requires a combustion efficiency test to begin with.0 -
Okay.....
How do you factor in whether it has a vent damper; or electronic ignition?
How do you account for a boiler with a circulator post purge cycle? With 3" of insulation vs. 1" of insulation?
Where did this formula come from?
Noel0
This discussion has been closed.
Categories
- 121.3K All Categories
- 84K THE MAIN WALL
- 2.9K A-C, Heat Pumps & Refrigeration
- 53 Biomass
- 417 Carbon Monoxide Awareness
- 40 Chimneys & Flues
- 1.7K Domestic Hot Water
- 4.7K Gas Heating
- 119 Geothermal
- 155 Indoor-Air Quality
- 3K Oil Heating
- 56 Pipe Deterioration
- 772 Plumbing
- 5.4K Radiant Heating
- 362 Solar
- 14K Strictly Steam
- 3K Thermostats and Controls
- 51 Water Quality
- 38 Industry Classes
- 73 Job Opportunities
- 19 Recall Announcements