I have a 15 year old Lennox 78% efficient furnace that I need to replace. The heat exchanger has been replaced once and we have noticed a boom when the gas draws in to ignite. We have the furnace serviced every Fall and A/C every Spring. It seems like small things are going wrong with it and we have had enough.
I contacted two reputable local contractors to give us a bid on a new furnace; 80% and 92% efficiency units for comparison purposes. We are leaning towards a Ruud 60,000 BTU 92% efficiency two-stage furnace (model UGRK 06)after talking to the contractors and researching on our own.
We live in East/Cenrtal Iowa and it appears that the 92% is the way to go.
Does anyone have opinions on the Ruud 92%? What about a 2 stage variable speed blower Ruud model?
The real purpose of posting this is that one contractor seemed to think that our duct work is fine that exists and the other one has issues with the duct work. A lot of what he said seemed to make sense, but I do have some reservations and want to make certain. I will list his concerns below.
(1) The air intake plenum necks down at the top to a dimension of 6" X 24". This is the only cold air return to the furnace. (our home is 975 Square foot (on the main level) ranch style home. We are heating the basement as we have a bathroom and exercise area down there. The contractor feels that we need more area for the intake and proposes adding another intake in the basement. He said the current furnace is starving for air with the current set up.
(2) He recommends adding a 6" Trion air filter. We have pets and my wife has allegies. I have looked into that previously and think that is a good idea. The first contractor said what we have now is fine (1" x 25" 3M allergen filter).
Is the Trion a real deal as far as minimizing the cat hair and dust?
(3) The transition from the furnace to the main heating plenum goes straight up into the bottom of the phlenum and obviously then hits the top of the phlenum before the heated air flows out to the ducts. The contractor recommend putting a 45 degree lead in on each side of the transition so it can branch to the phlenum with less turbulance.
Is this a real issue?
(4) The heating ducts that branch off from the main plenum are in question also. One runs straight out the end of the phlenum. The contractor suggests moving the duct to the side and extending the phlenum a couple of feet past the duct to minmize turbulance. The other end of the phlenum has 2 ducts right at the end and he feels that the phlemun should be extended a couple of feet there as well.
What do you think?
Our current furnace does make a lot of noise. My wife has complained about that since it was new 15 years ago. All of the duct work for the intake was redone then and it really was not a stellar job as far as workmanship in my opinion or hers. The contractor suggesting the duct reworking saw the unit and said immediately that the furnace needed a lot more intake than that to be efficient. He also explained that a lack of intake air flow could cause premature failure of a heat exchanger and other issues one of which was noisier than it should be. That grabbed my attention as we had not told him that the heat exchanger had been replaced 5 years ago, that it was noisy than the old one and that it cycled on and off a lot in the winter.
Please let me know what you think about any or all of these issues. I am always looking for all of the facts prior to making a decision that will impact us for the next 20 years or so. Your assistance is greatly appreciated.
Iowa Cool Cat