One week living with the new Evergreen IM Furnace Fan Blower Motor

It's been one week now since I installed the Evergreen IM furnace fan blower motor. In a word - Awesome. I am amazed at how quietly the system runs now. When in fan mode for circulating air from the heat recovery ventilator - you can now barely hear the air moving through the ductwork - yet it`s circulating almost 900 cfm. The furnace itself in the basement now runs almost silently, just a slight air circulation noise, and absolutely no motor noise.

When the system speeds up to 1500 cfm when the thermopump is running, you can hear the air circulating from the ducts, but there is no duct ticking noise or rattling noises - which I attribute to the cleaning of the accumulation of crud off the blower wheel improving its balance, and also the operation of the motor. Again, in the furnace room, the furnace just hums, with barely any motor noise, and just the faint noise of air movement. 

What an incredible difference in comfort and noise reduction, and then you have to consider the energy savings. I`m looking forward to the next two energy bills so that I can check to see if there has been a meaningful reduction in energy consumption matching my estimates. 

The result of this powerful demonstration of speed control and EC motor energy savings is that I`ve now turned my eye towards my 4 ton heat pump installed out back of the house. This unit is a 13 SEER single speed heat pump that rattles like an old volkswagon bus. The noise from our patio has always been annoying to say the least, and I even drew up plans to construct a noise barrier around the thermopump to try to block the rattle and noise from our patio. Following the fan motor upgrade, I`ve not started researching whether I can get a similar noise reduction and energy reduction advantage from replacing the heat pump. 

From what I`ve seen - that looks to be absolutely the case. A simple upgrade to a 2 speed heat pump with electronically commutated fan motor will allow the heat pump to operate most of the time at a lower speed (first stage) mode at lower heat transfer rates, for longer times, but at reduced energy consumptions. The indoor fan blower will run at a corresponding lower rate - lower energy cost, and low noise. When the heat pump is running at the first stage mode, it`s noise should be dramatically reduced as well - which will result in much less noise on the patio. 

I`m pretty excited about this discovery, but I plan to do my homework first and try to estimate the energy savings before pulling the pin on a new heat pump. It looks like to get the benefit of one of these higher SEER two stage units - I`ll have to upgrade my evaporator coil to run on a newer refrigerant - right now I`m running on R22. 

That`s all for now - I look forward to publishing my research and making the decision on this upgrade sometime this winter. For now though - I`m also looking at continuouse energy monitoring using a Brultech energy monitor. Will be reporting on my research on that as well. I`m thinking it will be useful to baseline the existing HVAC system energy consumption prior to the upgrade, to be able to better measure the resulting performance. 

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  1. Thanks for the post on Evergreen IM install, how much savings have you observed on your energy bill?

  2. I'll have to do some math on energy savings. This winter was much colder than the previous winter - and my winter electric bills have been about the same as last year. I'll eventually do a heating degree-days analysis to try to estimate the savings.