Since it looks like I'm needing a new furnace.... recomendations?

[louie]

My furnace has been determined to be unrepairable. Giving the HVAC contractor the benefit of the doubt for now and assuming he's correct in this determination (I'm willing to believe it - rusted out heat exchanger, rusted out burners, bad blower motor, furnace is approx 15 yrs old with some obvious water damage in and around the heat exchanger).

The house is unoccupied right now while we're doing rennovations and will probably remain so for the next 2 months or so, so I have the luxury of some time to look for a good but affordable furnace and contractor - though sooner is better since drywall mud dries VERY slowly in a cold house. Here are my needs/wants/ideas, please comment:

1) the house is approximately 1500 sq ft of living space, about 1000 of that is original, 2 1/2 story, 1920's, uninsulated construction (the rest is a single story addition with 2x4 walls and fiberglass insulation).

2) single pane storm windows throughout most of the house (I plan to eventually fix the insulation and windows when money and time allow, but the furnace is an immediate problem obviously)

3) The house has a brick/masonry chimney, at what efficiency rating is a PVC liner required (or am I wrong in thinking it's required at all?)?

4) I think a multi or variable speed blower would be beneficial, comments? worth the extra cost?

5) Is a two-stage burner worth the extra cost?

6) the current AC system appears to be an add-on system with an a-frame shaped evaporator installed into the supply plenum above the furnace (might have contributed to the water problems that rusted this unit out). I don't have the funds to replace this, but I might be able to re-install it properly if it is not currently right.

7) fuel is natural gas, installation is in the basement (unfinished - unlikely to ever be finished)

8) there is no filtration on this current unit, I'd like to add one but have not yet decided what type - leaning towards a basic, paper filter type. No major allergies in this household (some seasonal pollen allergies, minor)

Anyway, those are what I'm looking for in features. I've looked at Trane, Rheem websites so far and will keep trying to educate myself here. I'm also contacting local contractors to get quotes but haven't received any yet.

Thanks in advance for advice.

[louie]

forgot to mention that this is in the Baltimore, MD region. Winter appears quite mild so far compared to Syracuse, NY (recently moved).

[buffalobill]

replace the heat AND air conditioning newest and of the highest efficiency you can afford. and the sooner the better!. also book your insulation job today, there's a waiting list. an uninsulated house is too expensive to heat or cool these days. go variable speed blower and

2 stage burner if you can afford it after paying for replacement insulated windows and insulation. for maximum comfort and understanding if your system is operational, start operations with a simple thermostat so everybody can set it and be comfortable during your first year in your new house before you graduate to the vcr programming style thermostat that everyone hates. hang a separate digital thermometer and humidity receiver at the thermostat and the transmitter outdoors in the shade to the north side of the house so you can monitor the fun. read your gas meter and electric meter every day.

[scott21230]

Fix the insulation stuff first, then replace the furnace with something efficient. I would have to think that any house with a addition probably has an improperly sized furnace.

[m Ransley]

Most important is the installer he can make it all work right the first time, so talk to friends and neighbors. The more you know the more difficult it gets because so much is offered today. Efficiency goes from

80-95%, there are energy saving VS DC blowers,auto temp tracking humidifiers and complete thermostat control on high end units. Unless you live where heating and electric usage is low look into a 95% VS DC, but get the 10 yr warranty as there is more to go wrong.

Consumer Reports did a pole of apx 35000 over 5 years on reliability and goodman came in a clear winner of last place.

First you need a written load calculation on the house and maybe ductwork, Since you are insulating get it both ways, where you are now and with insulation. and try to go with the lowest btu you can , oversize and you will be less comfortable, heating to fast and unevenly, I insulated later and regret my equipment size as im oversized on heat and AC

3 pvc is used for direct vent units and need no chimney, you can vent out a wall

8 no filter, I bet your ducts are full of crap, Im sure there is a place for a filter or you didnt find it.

[SQLit]

Pretty well handled here.

I did some research AFTER I bought my unit and found that when looking at the higher MERV paper filters, the static pressure was to high for my unit. Get the contractor to put the next size grill in for the return that way you can use a higher MERV filter and still hold the static to where it belongs.

I offer these sites as help

http://198.147.238.24/ac_calc/default.asp You need to concerned about the heating more than the cooling. SEER is a seasonal COOLing figure.

Since there is a addition DEFINITELY ask for the calculation to be done on the duct work.

[Mark]

Some of the new furnaces with electronically controlled continuously variable speed blowers ...create lots of radio and TV interference... (I think it is Trane but not sure)

I hope the FCC goes after them soon...

Mark

[SQLit]

I had an older Trane (1990) with a VFD and there was no problems with interference.

[CBHVAC]

Well, right off the bat you need to get a complete Manual J load calculation, and a Manual D duct sizing calculation. If you cant find a contractor that will do that, pass on their services.

Well..actually... If you are going to get a new furnace, and then go adding insulation and windows, your manual J will be off after you insulate and then add better windows, and you might end up with an oversized unit. All that goes into consideration on sizing.

Newer 90% units do not use the chimney...they vent out PVC 3, 4 or 5 inch pipe.

Sure is...but get the extended warranty to 10 years on it...you will need it.

Extra cost? LOL..sorry...how much extra you talking about?

You are half assin this. Not to be rude, but Im not the sugar coating kinda guy...

First, all ACs like that are "add ons" and they need to be matched to the unit. You cant just go slap a furnace in and change the airflow and expect the ac to work right. it simply does not happen that way...not on older units. Also, after Jan 06, no cheaper AC units will be made. Its time to bite the bullet and get a loan if you have to, and have it done right. Period. Get a complete manJ and D, and go with what needs to be done.

All you need is pleated paper filters, but you will probably need a return replaced for this.

They are ALL garbage when half assed. I install york..some like em, some dont. I install Trane for the person that has more money than good sense. I wont install a goodman for any amount of money.

When you stated that the home had been added on, right off, you need to make sure its all sized right and chances are, its not. Figure a slightly larger unit will be determined to be required. The AC should be replaced at this time. Its much cheaper to do this now, than later. Your contractor will also find out with the manual D if the duct system is going to work with todays newer higher airflow units. The duct isnt an afterthought on the furnace..its part of it. Its either right, or its wrong. There is no "Ill do this later when I have money" as the furnace warranty states that improper installation voids it..and if the ducts not capable of handling it, its improper. Besides, you are about to drop alot of money...why half ass it, spend MORE than you have to, and still not be happy with it?