Springbok Home Inspections

Furnace inspection you need to do yourself.
It's time to check the furnace condensation pump and piping. I have a lot of customers who are having floods and water damage due to furnace condensate pumps failing. In many basements the space close to the furnace is used for storage. Items are stored on the floor. If the condensation pump fails, water leaks onto the floor and can cause a lot of damage. Remember that this water is also slightly acidic.
Mitigation:
Test the condensation pump. Pour water into the pump to force it to start up. Check that water is drained and the pump shuts off after draining the reservoir. Note if the pump’s check valve works properly. With long runs the water simply runs back into the pump as soon as it shuts down. This can lead to short cycling.

Place water or flood alarm sensors around the pump. Water alarms range from simple use-once-only to sophisticated wi-fi enable devices that can send a message to a cell phone if water is detected on the floor. The simple button type is around $30 for six at Home Depot. It’s well worth the insurance to use these devices.

A few interesting facts regarding the source of the condensation.
The water is a byproduct of the burning of natural gas and propane. Oil contains very little water and that is why there are no condensing versions of the oil furnaces. Natural gas contains a lot of water. In traditional furnace design the products of combustion that exit the furnace are held at 250 to 300F to avoid condensation. Remember the condensate is acidic and will lead to corrosion of the heat exchanger. In high efficiency or condensing furnaces the products of combustion is vented through a secondary heat exchanger in order to extract the additional heat.
The furnace will produce in the order of 0.8 to 1 gallon per hour of running. Total running time is dependent on many factors. However it is not uncommon for a furnace to produce 5 to 6 gallons of acidic condensate per day.
A furnace must be 90% Annual Fuel Utilization Efficiency (AFUE) or better to be called high efficiency.
The secondary heat exchanger is usually fabricated from stainless steel to slow down the corrosion process. The environment inside this heat exchanger is more challenging and one of the reasons why harsh chemicals such as paint remover should not be used in close proximity to a furnace. Especially when the furnace is operational. I mention this because a lot of basements are used as work shops during the winter months.

High efficiency furnaces are significantly more expensive, are they worth the cost and why are they being mandated?
Some basic physics to explain the efficiency gain from standard to high efficiency furnaces. One BTU is defined as the energy required to raise one pound of water by 1 degree Fahrenheit. So heating one pound of water from room temperature (70F) to boil (212F) required 142 BTUs.
Now if we take that pound of water at 212F and change the phase converting it to steam we need to add 970 BTUs.
The secondary heat exchanger is designed to cool the steam and extract that significant amount of energy that would be vented in a non-condensing or standard furnace.