HVAC Questions:

[rivan]

My house is about 60 years old, and the ducts probably aren't the most efficiently laid out - I know it's a tangled mess in the basement. The blower motor is something like 25 years old.

My electric bills are pretty high here, and I'm looking for ways to trim them.

Would I see a significant savings monthly by investing in a new blower motor?

Also - does anyone have links to guidelines on how to set thermostats for best efficiency? Maximum temp swings, timing tips (turn the heat off at 8 instead of 9 and save another 15% or whatever) or any other good reading on the matter?

 

[Kelemvor]

What kind of heat do you have? Furnace, oil heater, etc?

 

[rivan]

Gas furnace. The same blower also handles cooled air in the summer.

 

[Kelemvor]

Fan shoudl get replaced when the furnace gets replaced. How old is the furnace? 25 year old furnaces were normally around 65% efficient. After 25 years probably more like 60. Get a new 98% efficient one with a DC Variable speed motor and you'll save a bundle right there. If your A/C is that old as well, it could also be incredibly inefficient just to run.

Best part is, all Heating and A/C companies will come to your house for free and evaluate what you have and give you quotes for a new one. Have half a dozen or so people come out and see what they recommend.

As for the electric thermostat, the general rule of thumb is it takes less energy to maintain a set temperature the less difference there is between that set temperature and the outside temperature. SO setting the thermostats down when you won't be home for hours will save you money. THe more you set it down, the more you save. But then it just takes longer to heat back up so if your furnace is that inefficient, you might not be saving all that much.

 

[iamwiz82]

Originally posted by: Kelemvor
Fan shoudl get replaced when the furnace gets replaced. How old is the furnace? 25 year old furnaces were normally around 65% efficient. After 25 years probably more like 60. Get a new 98% efficient one with a DC Variable speed motor and you'll save a bundle right there. If your A/C is that old as well, it could also be incredibly inefficient just to run.

Best part is, all Heating and A/C companies will come to your house for free and evaluate what you have and give you quotes for a new one. Have half a dozen or so people come out and see what they recommend.

As for the electric thermostat, the general rule of thumb is it takes less energy to maintain a set temperature the less difference there is between that set temperature and the outside temperature. SO setting the thermostats down when you won't be home for hours will save you money. THe more you set it down, the more you save. But then it just takes longer to heat back up so if your furnace is that inefficient, you might not be saving all that much.

If you do have a HVAC company come out, make sure they do a complete survey. Lots of places will look at your old furnace's BTUs and then make an assumption based on that. A good company will take windows, orientation of the house, shadiness of the house, etc into count when they make a furnace size recommendation..

 

[rivan]

Thanks for the tips, guys. It's confirmed that it's at least worth getting some bids

 

[Mellman]

yeah i'd certainly get some bids, the variable speed fan is great - as is the more efficient units. replacing your duct work though - you're talking a huge task...

 

[drnickriviera]

Has anything else been done to the house to make it more efficent? You'll probably save much more by changing windows, adding insulation (are the walls even insulated?)