home heating equipment Audit

If you live in a cold climate and your energy consumption is like that of most homeowners, your space heating should account for about 40% of your energy bills – which means that auditing your heating equipment can be highly advantageous. In fact, as many studies also show, if your heating system isn’t working properly, or if it is too old, 30% to 50% of the used energy is being lost…

Any energy audit to the heating equipment will assess its 1) age and size; 2) the type of fuel; 3) maintenance issues; 4) the distribution system (ducts and pipes) and 5) its sealing and insulation. And based on it, it will include a set of recommendations over the best upgrades and the most cost-effective improvements.

Auditing the age and size of the heating equipment

Old gas and oil-fired furnaces and boilers have a low or very low energy efficiency. Values between 55% and 75% are very common, when compared to levels above 90%-95% for new units. Upgrading to modern heating systems can provide huge energy savings.

Take this into account, and pay also attention to the size of your equipment: oversized heating systems (oversizing was very common practice some years ago) are less energy-efficient.

The type of fuel

Heating audits may address the issue of the fuel: electricity, gas, oil, solar… In a large renovation (or if you plan to build a new home), that’s a very important issue, closely related to the definition of the type of space heating system.

To assess the cost-effectiveness of changing fuels, you should consider the cost and efficiency of the different alternatives.

Electricity is a costly source of energy, and electrical heating equipment should only be used for occasional uses and for small or relatively small needs in some climates and in some heating strategies. There is however a great exception: common heat pumps (using electricity) are a good option in moderate climates and whenever negative temperatures are uncommon; and ground and water heat pumps (geothermal energy) is very competitive and a good alternative to common central gas and oil-fueled heating systems even in colder climates (the problem with them is that they demand... an expensive initial investment).

As to gas vs. oil powered heating systems, though gas is almost always a better solution (economically and environmentally), the difference of costs can be small or reversed in some regions.

Auditing the type of heating system

The type of heating system depends largely on the type of home, climate and insulation levels. A small and very well sealed and insulated home will have small heating needs that can be fulfilled by small space electric or gas heaters, or gas stoves, even in cold climates. In this case, strategies based on heating zones can be a good solution.

But in most cases, for existing homes, the energy audit to the heating equipment doesn’t consider changing the type of system or fuel. That would demand a large investment, or another type of building… In this case, the audit is largely limited to improvements to the existing equipment, and to questions like its maintenance, insulation and sealing…

Reducing losses in the ducts or pipes (distribution system) is often the least expensive and the most cost-effective improvements involving the heating equipment. Un-sealed and poor insulated ducts can easily transfer large amounts of the heat produced by the heating system into non-living areas.

Auditing the maintenance and tuning the heating equipment

We list below the areas that are commonly assessed by heating equipment audits:

Central Forced Air systems:
- When was the furnace last serviced and cleaned, and the filters replaced?
- Which are the levels of the insulation of the ductwork running through un-heated basements, crawlspaces, or another un-conditioned space?
- Are the joints of the ducts properly sealed, with mastic or other good sealing material? Is the sealing material in good condition, or damaged or with open joints? And the ductwork runs? Are they in good condition?
- Are the holes and cuts (around each floor vent/register) conveniently sealed? They can be a major source of air leakage.

Hot Water/Radiant Heat (radiators, baseboards…)
- Are pipes conveniently insulated?
- Is the slab (of radiant heating systems) well insulated around its edges?
- Is there a reflective or an insulated panel, behind the radiators, to prevent heat loss at the wall?
- Are the wires coming from the wall or floor conveniently sealed?
- Are thermostats and wall fan heaters well tunned?
- Is the furniture sufficiently away from baseboards and heaters?

Audit heating equipment recommendations

The recommendations of the audit to the heating equipment will always be a direct result of the assessments listed earlier.

They will identify gaps and faults in the sealing and insulation of pipes and ducts or possible maintenance and inspection deficits; they may also recommend the replacement of valves (for boiler based systems) or the replacement of old and inefficient units by new efficient units with an efficiency often above the 95%, and in some cases the changing of the type of fuel, or a smaller system with higher levels of home insulation, or the use of heating zones (rooms relatively separated from the rest of the house, with specific heating loads and specific schedules, to minimize the overall heating needs)…