I am replacing a natural gas, forced air furnace in my house. The house is located near the Great Lakes and is 30 years old, 2 story, brick, 2800 sq. ft. good windows, with insulated basement. The furnace to be replaced is 30 yrs old, 90,000 BTU natural gas, forced air, early high efficiency. I have been informed a new style 70,000 BTU, 96% AFUE natural gas furnace would do the job...Which size should be installed?
Michael7777
55,000 BTU/HR for 2,800 S.F.. @ 0'F
60,000 BTU/HR Furnace _might be_ Adequate.
Two-stage should be investigated.
Heat Loss is calculated in the range of 55,000 BTU/HR (Attachment)
BASED ON
2,800 Sq Feet
30 years old
Great Lakes = 0'F Design Temperature
Do you have your Natural Gas bills (Therms used EACH Month) for the last 24 months?
_______________ ... :eek2: ... ___________________________
55,000 BTU/HR can be validated
for your specific house
given
N. GAS USAGE and Locale
(more accurate Heating Degree Days than 7,200 average)
60,000 BTU/HR Furnace _might be_ Adequate.
Two-stage should be investigated.
Heat Loss is calculated in the range of 55,000 BTU/HR (Attachment)
BASED ON
2,800 Sq Feet
30 years old
Great Lakes = 0'F Design Temperature
Do you have your Natural Gas bills (Therms used EACH Month) for the last 24 months?
_______________ ... :eek2: ... ___________________________
55,000 BTU/HR can be validated
for your specific house
given
N. GAS USAGE and Locale
(more accurate Heating Degree Days than 7,200 average)
30 years old, and early high efficiency don't track...
they didn't have induced draft in 84, they didn't have hot surface ignition in 84, they barely had intermittent pilot in 84... please list your model number of the equipment you now have.
most likely you have a 60% efficiency furnace with a pilot maintainer... possibly a mercury controlled pilot relight... fun system that.
if so, your system is tossing 40% of the fuel used up the chimney. so, your likely oversized 90 is only putting 50 into the structure... the ductwork likely is leaky, but should all be in the basement/between floors of the home, so losses don't count against the load. likely a 96% furnace in the 60K range will handle your home nicely. unless it was oversized to begin with... then a two stage or modulating furnace would be better, if not reducing to a 40 or 50K furnace, with adequate blower to handle your a/c airflow.
they didn't have induced draft in 84, they didn't have hot surface ignition in 84, they barely had intermittent pilot in 84... please list your model number of the equipment you now have.
most likely you have a 60% efficiency furnace with a pilot maintainer... possibly a mercury controlled pilot relight... fun system that.
if so, your system is tossing 40% of the fuel used up the chimney. so, your likely oversized 90 is only putting 50 into the structure... the ductwork likely is leaky, but should all be in the basement/between floors of the home, so losses don't count against the load. likely a 96% furnace in the 60K range will handle your home nicely. unless it was oversized to begin with... then a two stage or modulating furnace would be better, if not reducing to a 40 or 50K furnace, with adequate blower to handle your a/c airflow.
Hi everyone....Thanks for answering my question so quickly...Did some research and the furnace to be replaced was installed in 1984, an ICG natural gas furnace with electronic ignition, pressure switch and a vent fan which is vented outside horizontally with a plastic PVC pipe and the condensed water is run to a floor drain....So, this furnace must be a High Efficiency Condensing Furnace....I know we were told this was one of the 1st High Efficiency Furnaces available at that time......30yrs service, I don't think the new generation furnaces are made to last 30yrs today....I was concerned my HVC dealer was suggesting too drastic a downsize from 90,000 to 70,000 BTU....I have decided to replace with the 70,000 BTU, 96% AFUE natural gas furnace ...Thanks again
Hi everyone....yes, the original furnace was in Toronto, Canada....sorry no pictures as the ICG furnace was replaced with a 70,000BTU Goodman furnace today....Info on ICG furnace, Model #HCA090L, high efficiency, mfg 1984, input 90 btu, output 83.7 btu....From what I have researched, ICG (Inter City Gas, Toronto) was purchased by United Technologies - parent company of Carrier Co. and is now part of International Comfort Products. KeepRite is also part of International Comfort Products and many replacement parts for older ICG and KeepRite furnaces are the same or similar....
Just read "dan sw fl" reply "warmingupcanada" article and the description of the furnace is the ICG furnace I had replaced.....out of interest....Initial development of the condensing gas furnace in Canada---In late 1978, the Canadian Gas Research Institute (CGRI) in Toronto, Ontario advised Canadian gas furnace manufacturers it had developed a condensing technology that could potentially greatly improve the efficiencies of gas furnaces. The goal was 90 percent efficiency versus 78-80 percent for mid-efficient models and 60 percent for the old standard furnaces, to match new US condensing technologies.
Three companies signed confidentiality agreements to commit to produce such a product over 1979-80: Inter-City Gas Corp. of Winnipeg via its manufacturing division (Anthes, Bullochs, Furnasman); Clare Brothers, Preston, Ontario; and Clawsey-Short, Galt, Ontario. Little was known of this new technology, and the three participants soon realized CGRI’s condensing technology was not as far advanced as they had expected. The key issues of secondary heat exchanger material, condensate removal, and power venting were far from resolved in CGRI’s project.
Actual furnace design was also left to the participants. ICG and Clare chose the “wrap around” style of oil furnace heat exchangers, and power burners. ICG was the first on the market in 1980 with its “Ultimate” model, and Clare followed with its “Megasave” model, both near 90 percent efficiency ratings.
Unfortunately, for the manufacturers, the Canadian industry and initial customers, the first and second generation of these appliances were fraught with problems. They eventually disappeared and were replaced under licensing agreements by successful U.S.-designed units. The unresolved problems in those early Canadian-made condensing furnaces were still secondary heat exchanger failure; lack of knowledge of and product for condensate removal; the appliances’ physical dimensions; and premature failure of the power exhaust gas venters selected.....thanks again for your input.
Just read "dan sw fl" reply "warmingupcanada" article and the description of the furnace is the ICG furnace I had replaced.....out of interest....Initial development of the condensing gas furnace in Canada---In late 1978, the Canadian Gas Research Institute (CGRI) in Toronto, Ontario advised Canadian gas furnace manufacturers it had developed a condensing technology that could potentially greatly improve the efficiencies of gas furnaces. The goal was 90 percent efficiency versus 78-80 percent for mid-efficient models and 60 percent for the old standard furnaces, to match new US condensing technologies.
Three companies signed confidentiality agreements to commit to produce such a product over 1979-80: Inter-City Gas Corp. of Winnipeg via its manufacturing division (Anthes, Bullochs, Furnasman); Clare Brothers, Preston, Ontario; and Clawsey-Short, Galt, Ontario. Little was known of this new technology, and the three participants soon realized CGRI’s condensing technology was not as far advanced as they had expected. The key issues of secondary heat exchanger material, condensate removal, and power venting were far from resolved in CGRI’s project.
Actual furnace design was also left to the participants. ICG and Clare chose the “wrap around” style of oil furnace heat exchangers, and power burners. ICG was the first on the market in 1980 with its “Ultimate” model, and Clare followed with its “Megasave” model, both near 90 percent efficiency ratings.
Unfortunately, for the manufacturers, the Canadian industry and initial customers, the first and second generation of these appliances were fraught with problems. They eventually disappeared and were replaced under licensing agreements by successful U.S.-designed units. The unresolved problems in those early Canadian-made condensing furnaces were still secondary heat exchanger failure; lack of knowledge of and product for condensate removal; the appliances’ physical dimensions; and premature failure of the power exhaust gas venters selected.....thanks again for your input.
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