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new forced air gas furnace for colonial home built 1914 or so. I

Empire_2 Member Posts: 2,343
If you get a some time, can you please explain how the bypass humidifier has any affect or bearing on the eff. of any furnace and also where can I learn about the drawbacks of using the bypass humidifier shortening the life of the equipment. I haven't heard this and I would like to know.
Thank you in advance
Mike T


  • lida
    lida Member Posts: 1
    new forced air furnace for old home

    I have an old (1930s or so) GE gas forced air furnace that's oversized for my home. It's 70% efficient. I would like to replace it with a Rheems modulating furnace. Is this a good idea visa vis cost and comfort? We live in upstate New York where winters can be harsh, but aren't exactly artctic either. The exhisting duct work is in good shape. The ducts are probably ample sized, though they are not next to exterior walls. There is no cold air return on the second floor but I would like my laundry shoot convered into one. Can I get any feedback on other furnaces that may also be good. We intend to stay in this home for many years to come and don't mind investing in a qulaity product that will make a difference in our quality of life, but on the other hand, we don't want to buy something just because it's supposed to be good. We would like it to be effective in our home interms to maintaining a constant temp and a feeling of warmth while saving energy. We are also insulating ceiling and walls, and band joists.

    Any suggestions on what air cleaner system is most effective on cutting down dust bunnies and allergens in the air but still maintaining good air flow? (Kids have allergies and asthma) We would like to run the blower fan all the time to help balance temp and clean the air year round. I don't mind cleaning filters monthly if I can pop them in the dish washer.

    Also, winter finds us with extremely dry air upstairs. We would like a humidifer but I wonder if It's best to have it installed on the furnace or if stand alone units would be better. We have a humidity problem in the basement in the summer. Even though we run a dehumidifer, the basement humidity is usually around 57-59% during the summer. We spend a lot of time in the basement, it's part of our building envelope and would like to bring thehumidity down. Is it smart to have a humidifier installed with the furnace, and if so which one is recommended?

    Finally, how do I go about finding the right company and person in my area that will take the time to make a very thorough, good quality instillation?

    Thank you for your thoughts.
  • Timco
    Timco Member Posts: 3,040

    with the allergy / asthma problems, and the humidity problems, sounds like you need steam heat. You could also keep your laundry chute...we love ours!

    Just a guy running some pipes.
  • Empire_2
    Empire_2 Member Posts: 2,343
    My Opinion

    Carrier HVAC equipment is the way to go. They are leading the way in Variable speed Furnaces and air conditioning. I would not sell a Rheem To my mother...You can keep the shoot, but the R/A upstairs needs to be addressed. Where in Upstate NY are you? April Aire Humidifiers, and steam humidifiers are a great product for all your humidification needs. I would also look into heat recovery ventalator products to introduce fresh air into the structure. Although I do not like electronic air cleaners, their filtering % is in the hi 90%, but I am still "on the fence" on that.
  • Dirk Wright
    Dirk Wright Member Posts: 142
    Indoor Air Quality

    The best air cleaner is an electrostatic (sometimes called "electronic") type. The best furnace brand I know of is Thermopride:


    You want the top of the line model with the ECM blower, which will provide continuous ventilation in the house.

    You need a return duct for the upstairs, preferably separate ducts for each bedroom. See:

    I would also recommend a UV sterilizer in your supply duct over the A/C coil. There are several manufacturers, but I like Field Controls UV-Aire:

    You should also provide a means of supplying make up air. An inexpensive way to do this is by using the MAS from Field Controls. Otherwise, you can get an HRV.

    Since your children have health issues, then addressing indoor air quality is very important. These products will help.
  • Dale
    Dale Member Posts: 1,317
    Dealer is the key

    The climate in my area is similiar to where you are so I get this question alot. Before you spend any cash on a furnace get the house as insulated and tight as you can afford to, with the costs today a blower door test expense is well worth it. Then get the furnace. First, there are several good furnace brands on the high end, the key is the dealer. Who has been in business in your area the longest, what does the shop and trucks look like, what does your friends say about the service? ect. The parts for these furnaces are very pricy so I always say to price in the 10 year parts and labor warranty, and the parts are special so the "we service all brands" guy will NOT want to service the variable speed ECM variable input parts. Why, he can't afford to stock them and doesn't want to hunt them up or find them let alone tell you a blower motor replacement is $1200. So, if you go ECM and variable get the long warranty. As to brand, the ones mentioned are very good and I now, not 5-10 years ago but now, last few years, have seen almost no problems with the Rheem/Ruud product, IMHO their design and quality control improvement has been excellent. I have 4 year old 90% Bryant in my home that runs fine if a bit noisy but would get a bid on a Rheem lx2000 if I needed a new one. Elect. and gas prices along with quality make it worth it to me. Get a reasearch products space guard media filter, by far the most popular here, or an electronic. I would make sure there's room for a humidifier but not put one in until you have gone a winter with the new furnace, no air from the inside brings the humidity up. As to duct work, it is a crucial part of the design for alot of reasons and is part of the great contractor heating package.
  • Tim_24
    Tim_24 Member Posts: 53
    There are

    only 5 manufacturers of residential furnaces in the US, and they make all the dozens of brands. A well done installation with lower end equipment is usually superior to high end equipment installed poorly. So what I would recommend is that you decide upon with features you want to have and have the various contractors quote you for their product that has those features. Features to consider (or that I would choose): variable speed blower, 2-stage heat, 94% AFUE, lifetime heatexchanger warranty, 10 year parts warranty.

    Also, and this is a good way to weed out the hacks, have the contractors tell you what size furnace your house needs and why. The ones who will perform a load calculation and show it to you are the ones to consider further. Of course you must tell them up front to price the right sized furnace, not just replace with new.

    As far as air quality goes, Honeywell Envirocare products are at the top of the list. I prefer high quality media filters over electrostatic. In a home not under construction, the 5" thick filter element requires changing annually. (Note: a furnace and filter will not rid your house of dust, nor will it add to it; that is the realm of house cleaning) For forced humidification on a high efficiency furnace, a powered humidifier is recommended. The bypass type will reduce the overall efficiency of your furnace and will potentially shorten the life of the unit.

    All of these things will not significantly change the moisture problem in your basement during the summer. It is a classic problem not easiliy dealt with when foundations and basements are not externally insulated. Below 3 feet underground, the ground temperature and the temperature of the foundation walls are fairly consistent, typically in the middle to high 50's. If your house were cooled to 75 degF and 50% relative humidity (common design conditions for cooling), the dewpoint would be 63 degrees, higher than the temperature of half of your basement. A dehumidifier is a must, and air movement is very important.
  • Tim's right

    now is a good time for a hot-water or steam retrofit. If done right you'll be far more comfortable than you ever will even with the best forced-air heat system, and it will cost less to operate. Plus it won't blow dust and allergens around.
  • David DeBord
    David DeBord Member Posts: 4

    When you stand for The Truth, many times you will find yourself standing "alone"!

    First of all, I wasn't aware of "GE" producing a "forced air" furnace in the 1930's.Second, if it is that old,........it is more likely only 30 > 55% percent efficient, than your "70% efficiency" estimate.
    If you truthfully are looking for efficiency & warranty,......then yes, by all means replace this ancient relic & send it on it's way to some Chineese junkyard (LOL! that's where the bulk of our scrap is going these days!)
    "Cost of running, & comfort" will most defintely be improved as well as the means to "add on",.......Central air, humidification,improved means to clean the air & much more.
    Do not rely upon "the shape or condition of the ductwork", as to whether it is appropriate for a new installation. In most cases in my area, the return air registers, in an existing "gravity furnace" were located to the outside walls, with the supply registers located near the interior walls. These need to be removed & new supply registers located to the outside walls, & "Hi-wall"/ "Lo-wall" (or floor returns) located to the interior walls.Add "return air" to all rooms except for bath rooms, work shops, garages,utility rooms, & no closer than 12 feet (in a kitchen/dining area) from any cooking device such as a stove or grill.
    Many "dust bunnies" can be eliminated by "sealing up the duct work". All joints must be sealed with no cracks nor holes! Use something such as metal/silicon/ or foil tape. Air treatments can include electronic air cleaners/humidifiers/non electric "filter media" & "U V devices".
    A low wall return air in the basement, would work during the summer, as you would not have the furnace running! This return air grill would have to have a damper & be able to be fully shut off during the heating season so as not to recirculate any combustible products that might be pulled from the furnace during it's operation.
    As far as humuidifiers,my customers have had great success with by-pass & power humidifiers. The "drum type" humidifiers, in my opinion have far to many parts that break down & they require much more maintenance.
    As far as "a Contractor"?...........Start with your family & neighbors. Who is "satisfied" & "who is extremely pleased" with their installation & the service that followed? Then check their references. Who got service in the middle of the night, the weekends, & Holidays??

    Hope this helps & good luck!


  • Timco
    Timco Member Posts: 3,040

    there are probably dents in the floor where the rads were, and maybe pipes in the wall. May have been gravity furn the whole time. Who knows?

    Just a guy running some pipes.
  • tom_49
    tom_49 Member Posts: 269

    Carrier " infinity " gas furnaces are real nice, 2 stage gas valve, ECM variable speed motor (theyre very reliable ). Get the "infinity" control w/ it.

    For humidity, Nortec Resdelux, steam humidifier.

    For Heat recovery Ventilator, Carrier, April aire, Renuaire

    For air cleaner, I just saw American Standard makes a pretty cool unit, not sure what its called but it looks promising.

    April aire makes a free standing whole house dehumidifier model 1700.

    Thats my shopping list for goog FHA equipment.

    Most importantly, get a reputable contractor to do job w/ a manual J heat loss/gain done on house.

    Good luck
  • John L
    John L Member Posts: 118
    The best solutioin...............

    From reading your post I see that you have a few concerns namely comfort, efficiency, balalncing and long term peace of mind. If as you say this is your long term home, do your home work now to determine your choice of contractor and equipment. If you have been a visitor to this site you will clearly see that contractors who know their business are not the cheapest put there.look at this aa a long term investment that will start repaying immediately in terms of efficiency, comfort and rediced noise levels. Most contractors have a slight bias and so do I (Carrier).
    Check out the Carrier Infinity Two Stage Variable Speed Furnace and the Infinity Two Speed Air Conditioner which are combined with the Infinity Control System. You will satisfy all four of your concerns at once-reduced noise levels, improved efficiency, enhanced comfort through better dehumidification and better balancing from one of the premier brands in the industry.
    To get the best from the system, it appears that you need to have a second floor return, using the laundry chute should be ok as long as it is big enough, they usually are 12 x 12.
    If you can run ductwork for a zoning system then all the better. Add on a Humidifier, UV system, HEPA filtration, ERV system and now you have a comfort and efficient forced air system for as long as you live there.
    Pay attention to the contractor and their method of installation, the good ones will have pictures of previous similar installs to show you. Get a heat loss heat gain calc. done. Try and get a long term warranty- 10 year parts nad labor for instance. Good luck
  • darin_2
    darin_2 Member Posts: 12

    It's neat seeing people that are emotional about the products they sell. Alot of good advice was given. I put in a Carrier system with April Aire humidifier because I felt they were the best. The "humidistat" controls the furnace and the humidifier and opens the door to countless ways to customize the system's operation(four ways to control humidity alone):). My only concern with the Carrier unit(Bryant also) is that on LP the secondary can plug after a few years of operation. I would get a Carrier derivative at the 80% level with the ECM motors for more reliability on LP. Space Guard media air cleaners rock. April Air humidifiers are fantastic. Drum style humidifiers REALLY SUCK!!!! Good Luck.
  • Tim_24
    Tim_24 Member Posts: 53
    Recirculating warm

    air from the supply and evaporating as much water as it will hold, the passing this back through the furncae does several things: 1) raises the "return" temperature. This is the method by which the realized efficiency of the unit is lowered. Say for instance you have a furnace flowing 1000 cfm with a heat output of 65000, return at 60, discharge at 120. Recirc 10% of that and you now have return temperature of 66. Higher return equates to a lower "approch" temperature and a lower efficiency. The loss in efficiency is not quantified anywhere that I know of and real numbers would have to be developed by testing in standard conditions. My engineering estimate is that it is on the order of about 4-6%. Not great, but a reduction nonethelss.

    Secondly, the effects of adding moisture upstream of the blower (which is typically housed in the bottom of an upflow furnace with the exposed circuit board(s) and motor), heat exchanger(s) and cooling coil, is not specifically quantified by anyone as far as I know. Note that in my previous post is specifically said "potentially". It is soley my judgement that adding moisture by any amount to these components, overtime, mixed with some dust to give it some staying power and you have a recipe for reduced longevity. Manufacturers of commercial builtup air handlers and commercial humidification systems both recommed against adding moisture to the airstream upstream of fans, filters and coils. They must know something about the effects of moisture that would lead them to those recommendations.
  • John Mills_5
    John Mills_5 Member Posts: 950

    All they can offer is 2 stage. Even Goodman can do that for lots less money and probably more reliable.

    Only the Rheem Modulator can offer 13 stages. Only it can offer a variable speed blower that actually works in the heat mode to make the house more comfortable. It maintains a 65 degree temp rise over the 40-100% firing rate.

    The chart below shows just how closely the Mod's output can follow the heat loss of the house. The closest thing forced air can get to hydronic comfort.
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