Give your HVAC system an HE makeover

In Heating & Cooling 101 by Allan WLeave a Comment



Is your furnace or water heater is becoming outdated but you don’t have the cash for a nice new 97% efficient system? There are a number of retrofit options available that allow you to spruce up that old system and give it some modern performance. Double check with a professional before attempting any of these and also check to make sure it doesn’t (or that you’re OK with) violating any manufacturer’s warranties. Additionally, give some thought about saving up and replacing the furnace all together, once you have time to do these things, it is time to retrofit.


Derating Your Gas Burners/Down firing

(Leave this one to the professionals!) A lot of boilers or furnaces that you find in today’s homes are oversized, especially so if you have done other energy upgrades around the house. If this happens to be the case, you may be able to reduce the heating capacity of the appliance and save up to 15% in energy costs.

Derating means installing a lower gallon per hour nozzle to reduce fuel use. Doing so though, will most likely require a reconfiguring the shape or size of the combustion chamber and adjusting the fuel pump pressure.


Time Delay Relay (For Hot Water Boilers)

A time delay relay only costs costs somewhere in the neighborhood of $100 and can cut your fuel costs by up to 10%. A time delay relay is a way to maximize the heat out of your system without running the boiler. When the thermostat clicks on, the relay causes the boiler to circulate hot water through the system without turning on the boiler. After a certain, pre-determined set time, the boiler will fire up.

Vent Dampers

A vent damper prevents chimney losses by closing off a boiler’s vent when the boiler isn’t firing. Steam boilers benefit from vent dampers more than hot water boilers, and bigger boilers benefit more than smaller ones. The most common retrofit is the addition of a vent (or flue) damper, this may not be an option for newer model owners, but is a good solution for those with a dated one.

Intermittent Ignition Devices


(This is another one to leave to the professionals) Older furnaces and boilers have a continuous pilot light. These can be retrofitted with intermittent ignition devices ( they turn on and off by themselves). They cost about $250 and will typically pay for themselves inside of 10 years.

If it’s possible, turn off your furnace’s pilot in the spring and to turn it on again in the fall, you can usually save a decent amount of money this way.

Modulating Aquastats (For Hot Water Boilers Only)

An aquastat controls the temperature of the hot water in a boiler. It generally will be set to around 180 degrees. But often times the heating needs are less in the spring and fall. In this case, 180F is too high and is a potential energy waster. A modulating aquastat can sense the outdoor temperatures and adjusts the hot water temperature accordingly. These can save a great deal of energy over time


You don’t necessarily need a temperature sensing, modulating thermostat. An alternative would be to manually adjust the aquastat yourself, turning it down to around 120°F during the milder heating season.

As mentioned before, the optimum solution is to save some cash and replace the furnace all together. If that is definitely not an option, there is a number of options to help lower your energy bills in the winter months.

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