I have a 1200 SQFT home built in 1978 (in Edomonton, AB, Canada) with a basement and main floor. Current furnace is servicing basement and main floor, but is not operational (several problems, holes in heat exchanger, inducer motor seized, etc). I could replace the inducer motor and maybe get another year or so out of it, but wanted to consider replacement first.
I have had 2 quotes on replacement. The two contractors have recommended a 70 and 80 BTU furnace as the size for the entire house, respectively.
However I have a unique situation, which I've been expressing to the contractors, and don't seem to get a straight answer to a solution. The situation: the basement is currently unfinished. I intend to finish it into a secondary suite next Spring. In my town, this requires separate HVAC for main floor and the suite - either two furnaces, or furnace serving one and baseboard heaters + HRV serving other. I haven't decided which of those options I will do, but it will likely be baseboard+HRV.
Anyways, I want to know if it is possible to replace the furnace now, while still accomodating what I will need for the suite down the road.
The first contractor (who recommended 70 BTU for whole house) recomended that if I did two furnaces, each would be 45 BTU. He didn't do any formal calulations however.
The other contractor said that as long as I do two-stage, it doesn't matter if I replace current furnace with a 80 BTU, and then remove basement venting in Spring and have it just serving upstairs. This seems fishy - wouldn't this be oversized then?? It is ironic to me because the second contractor did a very detailed calc, measured windows, wood vs insulated doors, attic insulation, to come up with 80 BTU. But then when considering removing venting to the enitre basement as I would be doing, he didn't seem to be concerned that that would change the calculation???
Common sense tells me that I should just do the right size furnace for the main floor and that this wouldn't be the same as if I was doing the whole house. But I am wondering if anyone here can provide further clarification on this, or on what else I should be asking the contractors (two more coming for quotes next week)?
Additionally, if I have a smaller BTU furnace - should/can I leave the venting to the basement for the winter, or should it be capped now (ie. would I run the risk of undersizing the furnace, and would that matter if its only for one winter season). Capping also seems potentially problematic as the basmenet would be colder, and I have pipes down there - although maybe as long as the furnace is going it wouldn;t get below freezing temp. I'm not sure.
Thanks for any advice in advance!
Also can anyone point me to comparisons between brands, specifically Lennox vs. Carrier vs. Amana/Goodman? I'm looking at higher end furnaces, 96-98% efficiency. Cheers.
I have had 2 quotes on replacement. The two contractors have recommended a 70 and 80 BTU furnace as the size for the entire house, respectively.
However I have a unique situation, which I've been expressing to the contractors, and don't seem to get a straight answer to a solution. The situation: the basement is currently unfinished. I intend to finish it into a secondary suite next Spring. In my town, this requires separate HVAC for main floor and the suite - either two furnaces, or furnace serving one and baseboard heaters + HRV serving other. I haven't decided which of those options I will do, but it will likely be baseboard+HRV.
Anyways, I want to know if it is possible to replace the furnace now, while still accomodating what I will need for the suite down the road.
The first contractor (who recommended 70 BTU for whole house) recomended that if I did two furnaces, each would be 45 BTU. He didn't do any formal calulations however.
The other contractor said that as long as I do two-stage, it doesn't matter if I replace current furnace with a 80 BTU, and then remove basement venting in Spring and have it just serving upstairs. This seems fishy - wouldn't this be oversized then?? It is ironic to me because the second contractor did a very detailed calc, measured windows, wood vs insulated doors, attic insulation, to come up with 80 BTU. But then when considering removing venting to the enitre basement as I would be doing, he didn't seem to be concerned that that would change the calculation???
Common sense tells me that I should just do the right size furnace for the main floor and that this wouldn't be the same as if I was doing the whole house. But I am wondering if anyone here can provide further clarification on this, or on what else I should be asking the contractors (two more coming for quotes next week)?
Additionally, if I have a smaller BTU furnace - should/can I leave the venting to the basement for the winter, or should it be capped now (ie. would I run the risk of undersizing the furnace, and would that matter if its only for one winter season). Capping also seems potentially problematic as the basmenet would be colder, and I have pipes down there - although maybe as long as the furnace is going it wouldn;t get below freezing temp. I'm not sure.
Thanks for any advice in advance!
Also can anyone point me to comparisons between brands, specifically Lennox vs. Carrier vs. Amana/Goodman? I'm looking at higher end furnaces, 96-98% efficiency. Cheers.
source https://hvac-talk.com/vbb/showthread.php?2222612-Furnace-Replacement-Question-Size-Decision-for-Potential-Secondary-Suite&goto=newpost
No comments:
Post a Comment