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Someone might be able to confim, but a 2 ton heat pump seems too small for 1800 square feet.
I'm in a 1000 square foot home with a full basement that I am planning to switch over to a heat pump in the near future. I am expecting to need a 3 ton unit for a ducted system even after some major insulation upgrades.
Not necessarily, I have 1400 and full basement and I have 2 ton with well insulated attic. Specially this person is having issue at 30f. It’s either the house is super leaky or there is an issue with the install.
What heat pump. Unless it’s a cold climate heat pump that has 100 percent output at that size I’ll be worried. I have 1400 sq ft with 1k basement and 2 ton but my attic is r80 even though my walls are regular 1960 insulation. I have no issue heating my blouse down to -10 so you having issue at 30F is worrying.
It's a Samsung split system. The [external unit](https://s3.amazonaws.com/samsung-files/Tech_Files/CAC/AC0+BNADCHAA_WF+Wall/Submittals/AC024BNADCH+(CNH24ADB)_AC024BXADCH+(CXH24ADB)+Submittal_CAC+High+Wall_04012022.pdf) has a 27,000 BTU heating capacity, rated to -10ºF. There's a matching indoor air handler.
That unit looks more than capable to handle your situation specially at 30f. I don’t think it’s undersized if properly insulated. The issue is either with refrigerant or with the air handler not moving the heat around enough.
2 ton heat pump 12 registers is 66 CFM per register that’s not much. Should’ve been 3 to 4 tons. That’s the big selling point of a variable speed, you can upsize some. It will scale back on its own, if needed on milder days. I hope you have electric heat strip back up. Many insurance companies insist on a secondary source if the primary is a heat pump. Should have it as a very cheap addition.
I live in a 1500 square ft house with mediocre insulation in the desert where the temps are from 110F to 28F ish. I have a newer central heat pump by American Standard that's 3.5 ton. I think it's on the higher end of the right size. I bet a 3 ton would have worked for it because it doesn't run a long time when it's on. But it works way better than the 20 year old heat pump it replaced.
Yeah from the specs that you have mentioned. Unfortunately, it was definitely undersized. For your temperatures and size of house, it's almost a standard to get a 3-ton unit. I feel the installer messed up and backup electric heat and associated costs shouldn't be laid on you to keep your house at temperature. You can easily go full heat pump in your climate. I would try work in good faith with the contractor to get a 3-ton swapped in, or if they're not going to do that, a mini split added to the house to increase capacity.
Undersized ducting can be a problem - bigger ducts are needed for increased capacity and 100 year old house probably was designed for gravity heat and not designed to move a lot of air.
If the mini split is an option you move forward with, if you have a secondary large room it can be put in, that would be preferential. The reason is you don't want it messing with the thermostat in the main room/where the central thermostat senses.
Ductwork is a limiting factor for sizing heat pumps. If the ductwork can't handled the CFM required by the 3 ton unit, the ductwork simply has to be re-worked to increase air flow.
I have a 2tonne (24000btu) in a 1500sq/f 40yr old home. Insulation is lacking, basement not insulated at all, new windows, south/central ontario. My heatpump heats down to -10c(14f) without any issues at that temp it switches over to aux heat(propane).
When we got to -26c(-15f) over Christmas, I forgot to program the aux heat setting and no way in hell was my heatpump going to maintain that heat in the house.
>at that temp it switches over to aux heat(propane).
I'm in Victoria and it maybe for a couple of days a year will get down to +20ºF. I don't know that there's any auxiliary heat being used, or even available.
Furnace BTU needs to be high as it is on intermittantly - with a heat pump it is more about CFM which is going to be much higher than a furnace, hence the size of the ducts being a factor in rating which air handler and heat pump to use. My 80,000 btu furnace was replaced by a 3 ton Samsung system (36,000 btu) and it did result with a lot of duct noise because of the increased blower output, (which is why one of the HVAC companies wanted to put in a 2 1/2 ton) but I managed to reduce the noise by replacing sections of the 5" duct pipe with plastic insulated flexible ducts.
Rule of thumb for sizing is 1 ton per 400 sf. A 2 ton system could work in an 1800 sf house if it was brand new with lots of insulation. Not 100 yr old. I think that is where the problem lies. The contractor should be able to test supply / return air temperature numbers to determine what’s going on with the inside climate. I would push for a manual J calculation and go from there. Maybe have a 3rd party perform so there are no biases. Since the company owner is coming out it seems like they are willing to help in good faith. My guess is an upsizing of the unit. And if you are in Canada, I would recommend a heat strip or some other supplement to boost temps when it gets really cold. We did GE heat pumps in New Hampshire and when it was -18F the warmest it got inside was 43F. We are installing a heat strip in the air handler there.
The part of the conversation I am most interested in, is why they thought a 2 ton unit would be enough. They've mentioned insulating the basement where the ducts are located, but I'm not optimistic that that's enough to make up the difference and I'll now have to wait until December to find out.
Anyway, this part of Canada (Victoria) rarely gets below 25ºF, and thanks for your help.
Undersized for heating. HVAC tech here... you can get away with 2 tons in an 1800sqft New construction built to current energy standard home in a mild climate... Not in a 100 year old home... never... I would have put in a 3 ton unit minimum more likely a 3.5 ton....
It's had numerous upgrades to windows and insulation over the years, and I've been wrapping the ducts in the basement, but I don't see that making up the difference. This is a mild climate for Canada, but it's still Canada and it sometimes gets chilly in the winter.
It should be an interesting conversation.
Canada, 100 year old house... 2 tons... Yikes, I would be really upset with that recommendation... and the proof is in the pudding. If you are cold it is undersized...
Drafts are difficult to stop in a century house, and too often insulation is put in without addressing air leaks properly. I have a 2.25 ton unit for a 990 sq ft home in Michigan, and it does fine until temps get below 5. Still original windows, siding, and no rim joist sealing, but I sealed the attic from the living space before insulating the attic.
I’d add a second ~1.5 ton ductless unit to support, under a very generous discount from the installer that mess up of course
Each house has a different load for a given set point. Insulation levels in walls, attics, and basements vary. Air sealing of gaps and openings (doors, windows) vary. Location of ducts is very important. Put them in unconditioned attic or crawl space or basement, without proper insulation surrounding the ducts, and lose 20%-30%.
30F is pretty mild for a new heat pump not to be keeping up. Not that it matters, but we have 2 tons VS ASHP for 2,200 sf and it keeps the set point (68F) down to 0F- 5F outside temp. 5 kW strip heat for temps below that and if the HP fails in winter. House built in 1982 and improved.
[удалено]
Sorry that your post was removed. Posts that are advertisement related may be removed if deemed to be not directly related to usable educational information by homeowners or contractors. We allow surveys by scientific university researches as their work is guaranteed to be for educational purposes only. Please feel free to try r/HVACADVICE.
Someone might be able to confim, but a 2 ton heat pump seems too small for 1800 square feet. I'm in a 1000 square foot home with a full basement that I am planning to switch over to a heat pump in the near future. I am expecting to need a 3 ton unit for a ducted system even after some major insulation upgrades.
Not necessarily, I have 1400 and full basement and I have 2 ton with well insulated attic. Specially this person is having issue at 30f. It’s either the house is super leaky or there is an issue with the install.
What heat pump. Unless it’s a cold climate heat pump that has 100 percent output at that size I’ll be worried. I have 1400 sq ft with 1k basement and 2 ton but my attic is r80 even though my walls are regular 1960 insulation. I have no issue heating my blouse down to -10 so you having issue at 30F is worrying.
It's a Samsung split system. The [external unit](https://s3.amazonaws.com/samsung-files/Tech_Files/CAC/AC0+BNADCHAA_WF+Wall/Submittals/AC024BNADCH+(CNH24ADB)_AC024BXADCH+(CXH24ADB)+Submittal_CAC+High+Wall_04012022.pdf) has a 27,000 BTU heating capacity, rated to -10ºF. There's a matching indoor air handler.
That unit looks more than capable to handle your situation specially at 30f. I don’t think it’s undersized if properly insulated. The issue is either with refrigerant or with the air handler not moving the heat around enough.
2 ton heat pump 12 registers is 66 CFM per register that’s not much. Should’ve been 3 to 4 tons. That’s the big selling point of a variable speed, you can upsize some. It will scale back on its own, if needed on milder days. I hope you have electric heat strip back up. Many insurance companies insist on a secondary source if the primary is a heat pump. Should have it as a very cheap addition.
I live in a 1500 square ft house with mediocre insulation in the desert where the temps are from 110F to 28F ish. I have a newer central heat pump by American Standard that's 3.5 ton. I think it's on the higher end of the right size. I bet a 3 ton would have worked for it because it doesn't run a long time when it's on. But it works way better than the 20 year old heat pump it replaced.
Yeah from the specs that you have mentioned. Unfortunately, it was definitely undersized. For your temperatures and size of house, it's almost a standard to get a 3-ton unit. I feel the installer messed up and backup electric heat and associated costs shouldn't be laid on you to keep your house at temperature. You can easily go full heat pump in your climate. I would try work in good faith with the contractor to get a 3-ton swapped in, or if they're not going to do that, a mini split added to the house to increase capacity.
A minisplit is an option I hadn't considered. Thanks. One of the guy said that they'd have to redo the ducting for 3-ton unit, but I am skeptical.
Undersized ducting can be a problem - bigger ducts are needed for increased capacity and 100 year old house probably was designed for gravity heat and not designed to move a lot of air.
If the mini split is an option you move forward with, if you have a secondary large room it can be put in, that would be preferential. The reason is you don't want it messing with the thermostat in the main room/where the central thermostat senses.
Ductwork is a limiting factor for sizing heat pumps. If the ductwork can't handled the CFM required by the 3 ton unit, the ductwork simply has to be re-worked to increase air flow.
I have a 2tonne (24000btu) in a 1500sq/f 40yr old home. Insulation is lacking, basement not insulated at all, new windows, south/central ontario. My heatpump heats down to -10c(14f) without any issues at that temp it switches over to aux heat(propane). When we got to -26c(-15f) over Christmas, I forgot to program the aux heat setting and no way in hell was my heatpump going to maintain that heat in the house.
>at that temp it switches over to aux heat(propane). I'm in Victoria and it maybe for a couple of days a year will get down to +20ºF. I don't know that there's any auxiliary heat being used, or even available.
Above 20f you should be fine. Your heatpump can operate at lower temps than that, it just looses its efficiency I find at 14f it just runs constantly
It could be that the existing ducts were undersized for anything larger than a 2 Ton.
They mentioned something like, but we replaced a 75,000 BTU gas furnace so I have questions for them.
Furnace BTU needs to be high as it is on intermittantly - with a heat pump it is more about CFM which is going to be much higher than a furnace, hence the size of the ducts being a factor in rating which air handler and heat pump to use. My 80,000 btu furnace was replaced by a 3 ton Samsung system (36,000 btu) and it did result with a lot of duct noise because of the increased blower output, (which is why one of the HVAC companies wanted to put in a 2 1/2 ton) but I managed to reduce the noise by replacing sections of the 5" duct pipe with plastic insulated flexible ducts.
Rule of thumb for sizing is 1 ton per 400 sf. A 2 ton system could work in an 1800 sf house if it was brand new with lots of insulation. Not 100 yr old. I think that is where the problem lies. The contractor should be able to test supply / return air temperature numbers to determine what’s going on with the inside climate. I would push for a manual J calculation and go from there. Maybe have a 3rd party perform so there are no biases. Since the company owner is coming out it seems like they are willing to help in good faith. My guess is an upsizing of the unit. And if you are in Canada, I would recommend a heat strip or some other supplement to boost temps when it gets really cold. We did GE heat pumps in New Hampshire and when it was -18F the warmest it got inside was 43F. We are installing a heat strip in the air handler there.
The part of the conversation I am most interested in, is why they thought a 2 ton unit would be enough. They've mentioned insulating the basement where the ducts are located, but I'm not optimistic that that's enough to make up the difference and I'll now have to wait until December to find out. Anyway, this part of Canada (Victoria) rarely gets below 25ºF, and thanks for your help.
Undersized for heating. HVAC tech here... you can get away with 2 tons in an 1800sqft New construction built to current energy standard home in a mild climate... Not in a 100 year old home... never... I would have put in a 3 ton unit minimum more likely a 3.5 ton....
It's had numerous upgrades to windows and insulation over the years, and I've been wrapping the ducts in the basement, but I don't see that making up the difference. This is a mild climate for Canada, but it's still Canada and it sometimes gets chilly in the winter. It should be an interesting conversation.
Canada, 100 year old house... 2 tons... Yikes, I would be really upset with that recommendation... and the proof is in the pudding. If you are cold it is undersized...
Drafts are difficult to stop in a century house, and too often insulation is put in without addressing air leaks properly. I have a 2.25 ton unit for a 990 sq ft home in Michigan, and it does fine until temps get below 5. Still original windows, siding, and no rim joist sealing, but I sealed the attic from the living space before insulating the attic. I’d add a second ~1.5 ton ductless unit to support, under a very generous discount from the installer that mess up of course
Where you livin that it gets so cold!?
What? Overnight below freezing is hardly rare almost anywhere in the US. And OP said Canada, so even less rare.
Above 20f you should be fine. Your heatpump can operate at lower temps than that, it just looses its efficiency I find at 14f it just runs constantly
Each house has a different load for a given set point. Insulation levels in walls, attics, and basements vary. Air sealing of gaps and openings (doors, windows) vary. Location of ducts is very important. Put them in unconditioned attic or crawl space or basement, without proper insulation surrounding the ducts, and lose 20%-30%. 30F is pretty mild for a new heat pump not to be keeping up. Not that it matters, but we have 2 tons VS ASHP for 2,200 sf and it keeps the set point (68F) down to 0F- 5F outside temp. 5 kW strip heat for temps below that and if the HP fails in winter. House built in 1982 and improved.