Combustion Safety and Efficiency for your Home!

April 12th, 2012
Bhaskar Ale- MSME, E.I.T

Do you think your heating system might be coming to the end of its useful life.  Are you worried about health and safety issues that come with an older heating system? Well it might be time to get it checked by an professional HVAC specialist or have a energy and safety audit for your heating system and other combustible appliances in your home.

Combustion heaters are among the most dangerous equipment in your home. Indoor air and fire hazards are the main concerns. They are especially more dangerous in single family homes where residents lives in close proximity to the combustion appliances. The use of oil heaters is uniquely challenging  as they have more moving parts and subsequently more maintenance and safety issues.

Health and safety is an even greater concern than energy efficiency when it comes to heating systems.  The main safety issue is the carbon monoxide content in the air. Carbon monoxide is the by product of incomplete combustion from fossil fuel and oxygen. CO is a colorless, odorless gas that can sicken and if found in large quantities can actually kill a person. Hence, every house should have a CO monitor as a safety precaution. There are other by products as well which include harmful gases such as sulphur dioxide and nitrous oxide.

Hence, even installing a CO monitor is not going to tell you that your furnace/boiler or water heater are upto the standards for safety.

To test for combustion safety, there are 3 test procedures followed according to BPI (Building Performance Institute):

  1. General Inspection

 It basically consists of looking at the following

  • equipment age
  • manufacturer
  • size
  • flue inspections
  • pipes insulation
  • filter inspection
  • sniff for gas leakage using leak detector
  1. Worst case depressurization testing (CAZ test)

This determines if the exhaust fans in the  house can create enough competition for the air to backdraft the heater or hot water heater. If the appliance vents sufficiently in worst case scenarios, they should also vent under normal conditions. The limits in terms of pascals reading are compared with BPI Combustion Appliance Zone (CAZ) Depressurization Limits (Pa) for safe conditions.

  1. Draft, spillage, CO and efficiency of the combustion appliances.

 All combustion equipment are tested for Draft, spillage, CO and efficiency. First spillage is tested, i.e the flue gases venting out, if it keeps pouring out for more than 60 seconds then the appliance fails. Then next the draft pressure is measured using a manometer and compares of ‘Minimum acceptable draft test readings table’. Then the CO level and combustion efficiency is measured.

The tools used or equipment required for the test are the following:

  • Ambient CO monitor
  • Combustion Analyzer
  • Manometer
  • Gas Leak Detector
  • Smoke Pen

These tests will definately help keep your home safe from air pollutants and fire hazards. You might have to insulate your heater and pipes or seal up the duct vents or sometimes buy a new heater but with the available rebates and interest free loans (HEAT loan) availabele from Mass Save and other utilities in MA, it has become much more affordable. If you would like to find out more about combustion safety standards used for comparison then definately visit for further information. If you would like more information on the rebates then visit my previous blog on Mass Save or visit