Home & Garden

Trane vs Carrier hybrid system

  • Last Updated:
  • Oct 11th, 2023 2:57 pm
Member
Apr 26, 2022
317 posts
232 upvotes
Toronto
1chinaman wrote: 59TP6 does have a DHUM terminal, also has Y1 and Y2 terminals…if you get where im going.
I’m not recommending deviating from the wiring instructions but something I’d try if I had one and see how the 38MARB cooperates.
Ok well that's interesting. I didn't see DHUM or separate Y terminals in the circuit diagram but perhaps that's intentionally left out of the documentation by Carrier.
The uncertain part is as you said, how will the 38MARB cooperate? For DHUM to work well, the outdoor unit would have to be forced to run at a higher power which it may not do if the return air isn't hot enough.
Member
Jun 22, 2003
379 posts
180 upvotes
Oakville
Invalid12 wrote: Supplied with an Ecobee.

Yes it was the lowest cost - but hard to find a apples to apples comp. A Bryant dealer quoted 3k more for the same setup.

I needed a 2 ton HP to meet my AC loads paired with a traditional furnace. That really narrowed down my choices as the HP's that qualify for the rebate are 1.5 ton or smaller ductless or larger fully communicating units. I think that mid tier fully inverted hp's are relatively new as not too long ago 2 stage HP's were the mid tier option.

I think Carrier has such a large product line they were able to mix and match a mid tier setup with a 24volt communication module to fit the specs required for the full rebate.
Hey, question about the rebate for 38MARB. I am also looking at getting something similar - 38MURA. Its similar to 38MARB but goes upto 5T (only upto 4T is eligible for rebate). The question I have is about eligibility.
https://oee.nrcan.gc.ca/pml-lmp/index.c ... P1_GH&nr=1
This lists inside model as: 40MBABQ30XB3 which is blower + coil. Since you went with furnace I am assuming your inside model is different, did that quality for max rebate without any issues?
Member
Apr 26, 2022
317 posts
232 upvotes
Toronto
Y2BNE1 wrote: Hey, question about the rebate for 38MARB. I am also looking at getting something similar - 38MURA. Its similar to 38MARB but goes upto 5T (only upto 4T is eligible for rebate). The question I have is about eligibility.
https://oee.nrcan.gc.ca/pml-lmp/index.c ... P1_GH&nr=1
This lists inside model as: 40MBABQ30XB3 which is blower + coil. Since you went with furnace I am assuming your inside model is different, did that quality for max rebate without any issues?
Hey @Y2BNE1 , yes I am aware of the MURA. I'm told it's a slightly newer version of the MARB. I also noticed that the MURA is only available with fan coils not furnaces, whereas the MARB is available with either.
Both matchups qualify for the same max rebate of $5,000 under Greener homes or $6500 under the Enbridge HER+ program.
Curious where you are located and who is offering the MURA. I was told by a couple installers that the MURA isn't available yet, however I'm not sure if that's a fact or if they're just trying to clear out the MARBs.
Member
Jun 22, 2003
379 posts
180 upvotes
Oakville
I am in Oakville, 3300 sqft home, but am not in a rush to upgrade to it. Current furnace is ~20yo). Switching to heat pump was one of my retrofit options under initial Greener Homes Grant, but we simply couldn't find anything at the time that would qualify for the loan (before HER+ was announced). In the end I am going with 14kw solar install and replacing couple of sliding doors. Under older Greener Homes max rebate was 5k, which is fully taken up by my solar.

Now that HER+ is available with additional rebates for heat pumps I am looking into it again. 38MURA for home my size is https://ashp.neep.org/#!/product/64690/7/25000///0.

There quite a few variables at play in my mind:
1) It seems that while 38MURA High Heat is able to go down quite low while providing significant heat, its not very efficient at cooling. So it will end up using quite a bit of electricity almost year round.
2) Maybe it would make more sense to get non cold climate heatpump which is much more efficient while cooling and would be able to provide heat for edge months (and in case of this year, most of winter) and pair it with furnace for extreme temps. I also won't be able to get rid of natural gas completely as we have pool heater / fireplace / stove.

Higher rebate ($6500) also won't matter for me as I believe 10K is max, and I've already used up 5k for my solar.

Since I've already done my initial assessment (and it suggests replacing furnace with heatpump), my goal is to complete my solar + doors install and do post install assessment to get the loan + grant for solar, and then apply to HER+ with same initial assessment if I find heatpump that makes sense.
Member
Apr 26, 2022
317 posts
232 upvotes
Toronto
Y2BNE1 wrote: I am in Oakville, 3300 sqft home, but am not in a rush to upgrade to it. Current furnace is ~20yo). Switching to heat pump was one of my retrofit options under initial Greener Homes Grant, but we simply couldn't find anything at the time that would qualify for the loan (before HER+ was announced). In the end I am going with 14kw solar install and replacing couple of sliding doors. Under older Greener Homes max rebate was 5k, which is fully taken up by my solar.

Now that HER+ is available with additional rebates for heat pumps I am looking into it again. 38MURA for home my size is https://ashp.neep.org/#!/product/64690/7/25000///0.

There quite a few variables at play in my mind:
1) It seems that while 38MURA High Heat is able to go down quite low while providing significant heat, its not very efficient at cooling. So it will end up using quite a bit of electricity almost year round.
2) Maybe it would make more sense to get non cold climate heatpump which is much more efficient while cooling and would be able to provide heat for edge months (and in case of this year, most of winter) and pair it with furnace for extreme temps. I also won't be able to get rid of natural gas completely as we have pool heater / fireplace / stove.

Higher rebate ($6500) also won't matter for me as I believe 10K is max, and I've already used up 5k for my solar.

Since I've already done my initial assessment (and it suggests replacing furnace with heatpump), my goal is to complete my solar + doors install and do post install assessment to get the loan + grant for solar, and then apply to HER+ with same initial assessment if I find heatpump that makes sense.
Big house! How did your energy audit look - what was the heat load, cooling load and ACH? If your current hvac system is a single stage you can actually make your own load chart using the runtimes from a smart thermostat, which will be more accurate.

I'm in a 1500 sqft house (excl. basement) in Toronto. I personally found there to be a huge discrepancy between what the auditor calculated (37,700 BTU/h) versus my actual load (24,500 BTU/h). This is good information as I can avoid oversizing my new equipment.

In either case I think hybrid is going to be great for both of us. We can also adjust the switchover point as needed depending on goals (comfort, efficiency, cost).

You noticed the same thing as me - the efficiency of the Carrier heat pumps (which are just rebadged Midea units), are reasonably good but nothing ground breaking, especially when the weather gets cold. They ramp up their power to produce more heat yes but it's at a cost that will likely be more than gas. Depending on your goals this might actually be fine but since you're keeping your gas service, might as well go hybrid. This should also extend the life of the heat pump as it won't be used as much.

I noticed the better a heat pump works in cold climate, the less likely it is to be bundled with a gas furnace in a hybrid matchup by NRCAN. The 38MARB is a bit of an exception as it's available in both all-electric and hybrid matchups.

I'm not sure how the rebate program works in terms of multiple upgrades and the timing of the post-audit. I thought the post-audit had to happen after ALL upgrades were completed. You should probably check with the auditor to confirm.
Member
Jun 22, 2003
379 posts
180 upvotes
Oakville
Yup, big house with lots of original builder windows (vinyl but whatever was between glass is long gone). 53m^2 of windows so its pretty tricky to keep cool and warm.
ACH is 4.18, but we found some pretty huge drafts from one disconnected exhaust, so I'll be addressing that DIY.

My design heating load: 25kwh which is way too high. I do have single stage furnace and ecobee and I calculated my actual heating load @ -8c to be around 36000BTU/h. Hoping replacing 2 sliding doors will help that a bit, and am also planning to replace some windows glass units with low-e myself. Replacing all windows would be closer to 100K... (cant justify that)

I got my loan approved before HER+ was announced so I am still going by original Greener Homes Grant. Based on what I was reading, I should be able to apply for HER+ again for the retrofits that were not completed as part of original GHG. My main priority right now is getting solar and doing post assessment so that I can get the loan funded. Once that's complete I'll figure if I can use original assessment (I have not read about any expiration dates for those) to apply for HER+ and then might need to do another post assessment.
Member
Apr 26, 2022
317 posts
232 upvotes
Toronto
Y2BNE1 wrote: Yup, big house with lots of original builder windows (vinyl but whatever was between glass is long gone). 53m^2 of windows so its pretty tricky to keep cool and warm.
ACH is 4.18, but we found some pretty huge drafts from one disconnected exhaust, so I'll be addressing that DIY.

My design heating load: 25kwh which is way too high. I do have single stage furnace and ecobee and I calculated my actual heating load @ -8c to be around 36000BTU/h. Hoping replacing 2 sliding doors will help that a bit, and am also planning to replace some windows glass units with low-e myself. Replacing all windows would be closer to 100K... (cant justify that)

I got my loan approved before HER+ was announced so I am still going by original Greener Homes Grant. Based on what I was reading, I should be able to apply for HER+ again for the retrofits that were not completed as part of original GHG. My main priority right now is getting solar and doing post assessment so that I can get the loan funded. Once that's complete I'll figure if I can use original assessment (I have not read about any expiration dates for those) to apply for HER+ and then might need to do another post assessment.
Well it sounds like you're on the right track.

As for the heat pumps, if I were you I'd maybe wait a bit, as there should be some more interesting products coming out next year.
There's also mitsubishi's intelliheat coils coming soon which could be of interest if they start including them in the rebate programs.
And if you haven't come across it yet, Trane's XV19 that I'm considering also comes in a 4 ton size paired with a 2 stage furnace although it is 100kbtuh which is kinda big probably even for your house. The only downsides with the XV19 system seem to be the proprietary thermostat is kind of shitty from an tech and design perspective, and lower rebate amount as it's not a cold climate model.
trane-4ton.png
Member
Apr 26, 2022
317 posts
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Toronto
Heat pumps eligible for a federal rebate....

I saw that they update the list quarterly. The next update is supposed to be in March.

From the Greener Homes website:
Regular quarterly updates to the Canada Greener Homes Grant searchable product list occur in March, June, September and December of each year. All updates will be made to ensure homeowners have access to grants for all products available that meet the performance criteria set by the initiative. These updates also acknowledge innovation and advancements made by manufacturers as they improve technology performance for new models. All eligible product lists are available in an online searchable format, linked from the Canada Greener Homes Grant website.
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tomtomk wrote: Heat pumps eligible for a federal rebate....

I saw that they update the list quarterly. The next update is supposed to be in March.

From the Greener Homes website:
Regular quarterly updates to the Canada Greener Homes Grant searchable product list occur in March, June, September and December of each year. All updates will be made to ensure homeowners have access to grants for all products available that meet the performance criteria set by the initiative. These updates also acknowledge innovation and advancements made by manufacturers as they improve technology performance for new models. All eligible product lists are available in an online searchable format, linked from the Canada Greener Homes Grant website.
Thanks for the info, getting another quote today for Carrier heat pump and this company also mentioned the larger 2.5 ton heat pump model is still going through rebate eligibility review with time frame of late spring or early summer for approval. Hopefully it gets updated in March.
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Apr 26, 2022
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Toronto
jumran wrote: Thanks for the info, getting another quote today for Carrier heat pump and this company also mentioned the larger 2.5 ton heat pump model is still going through rebate eligibility review with time frame of late spring or early summer for approval. Hopefully it gets updated in March.
Good to know... and sounds like if we hold out until April(ish) there could be some new options available.
I'm more interested in new 2-ton systems that are more full featured but sounds like you want a bigger unit...
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tomtomk wrote: Good to know... and sounds like if we hold out until April(ish) there could be some new options available.
I'm more interested in new 2-ton systems that are more full featured but sounds like you want a bigger unit...
Based on my current ac size and 2200 sq ft space, 2.5 ton is being suggested. At that size the current options are too expensive so will have to see if new approved ones are within my budget.
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Apr 26, 2022
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Toronto
jumran wrote: Based on my current ac size and 2200 sq ft space, 2.5 ton is being suggested. At that size the current options are too expensive so will have to see if new approved ones are within my budget.
2200 sqft including or excluding basement?

Does your existing system work hard on the hottest days or does it toggle on and off a lot?

Have you had an energy audit done already?
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tomtomk wrote: 2200 sqft including or excluding basement?

Does your existing system work hard on the hottest days or does it toggle on and off a lot?

Have you had an energy audit done already?
2200 sq feet including finished walk out basement. Current system struggles to keep up in hot days specially upper floors but that may be due to issues with my duct leakage and lack of return airs in upper floor (only one in upper hallway).
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Apr 26, 2022
317 posts
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Toronto
jumran wrote: 2200 sq feet including finished walk out basement. Current system struggles to keep up in hot days specially upper floors but that may be due to issues with my duct leakage and lack of return airs in upper floor (only one in upper hallway).
@jumran Your ducts may be a limiting factor here but assuming you're not going to touch your ducts, you can calculate your house's heat load yourself with your smart thermostat and current furnace if it is single stage. (I also sent you instructions to your inbox).

Plot Avg btu/h vs Avg outdoor temperature for multiple days:
  • Calculate Avg BTU/h using the formula: (runtime hrs / 24) * (furnace capacity * efficiency). E.g. if your furnace ran for 6 hours during a full day, and you have a 90% efficient 70,000 BTU/h furnace, the calculation would be: (6/24) * (0.9 * 70000) = 15,750 BTU/h.
  • Find daily historical averages here: https://climate.weather.gc.ca/historica ... ata_e.html.
Note: Older furnaces probably don't reach their stated efficiency though, so if your furnace is marked as a 90% AFUE but it's 20 years old, it may only be 85% or worse at this point.

There are also methods to calculate heat load using your natural gas consumption on your bill, however this can be tricky if you have other gas appliances. I personally think the furnace runtime method is better (note: it only works if you have a single stage furnace otherwise it's hard to calculate).

Once you have your load line, add the winter design temperature. This varies by location. I found this site to be reliable: http://ashrae-meteo.info/v2.0/places.ph ... %20America. The temp you are looking for is the heating 99% DB (dry bulb). For pearson this is -15.7 C or approx -4F.

The point at which your load line intersects the winter design line is your max heat load for 99% of the year. Do not size your equipment for exactly this because then your system won't keep up during cold snaps / extremes (1% of the time). The rule of thumb is about 140% of design = system capacity. Or you can just follow the line on the chart until a point where it meets the coldest possible day, and that'll be your absolute max load requirement.

The finished load chart should look something like this.... (this is for my house).

heat-load.png

The same method can be used to find your cooling load in the summer, so long as your outdoor unit is also a single stage.
Last edited by tomtomk on Jan 31st, 2023 8:45 pm, edited 1 time in total.
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I have good run time data from 3rd party app that taps into ecobee data. Will crunch the numbers and see if I can narrow down my requirements.
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Jan 19, 2013
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Ottawa
tomtomk wrote: Well it sounds like you're on the right track.

As for the heat pumps, if I were you I'd maybe wait a bit, as there should be some more interesting products coming out next year.
There's also mitsubishi's intelliheat coils coming soon which could be of interest if they start including them in the rebate programs.
And if you haven't come across it yet, Trane's XV19 that I'm considering also comes in a 4 ton size paired with a 2 stage furnace although it is 100kbtuh which is kinda big probably even for your house. The only downsides with the XV19 system seem to be the proprietary thermostat is kind of shitty from an tech and design perspective, and lower rebate amount as it's not a cold climate model.

trane-4ton.png
Mitz intelliheat should be already here to select dealers, I can see pricing already.
Looks like they meet the minimum efficiency for the rebate program, hopefully they make the updated official list shortly.
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Feb 20, 2018
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Invalid12 wrote: <snip>
My pre audit is complete and installation is booked for next week.
Hi @Invalid12 how did your installation go? Would be great if you are able to share your experience and any photos of the completed install. Thanks!
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Feb 25, 2015
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anandoc wrote: Hi @Invalid12 how did your installation go? Would be great if you are able to share your experience and any photos of the completed install. Thanks!
Hey - Yes its all installed and I've had some time to figure things out. So far I'm happy with it :)

Install took two days and a couple hours on a third day to finish charging the lines and commissioning. My post audit is complete and I'm waiting for the $7100 rebate from Enbridge. I asked the contractor if this type of setup with rebates has kept him busy, he replied that he's been installing 2 per week - same Carrier setup since the Greener homes grants started.

My heat pump is sized for cooling but with this winter being mild, the furnace has only kicked on a handful of days. my setup is a 2-ton HP an it heats our home until outdoor temp drops blow (-7c), then switches automatically to stage 1 furnace 39k btu/h ng then if needed 59k btu/h stage 2. This has replaced a builder grade 24 yr old 100k btu/h 90% efficient furnace. I'm still playing with the lockout set temp but I'm really happy with the results so far. I'm actually amazed the hp sized for cooling can provide enough heat for our 2200sqft home below freezing. The hp does run longer but it keeps the home to within half a degree Celsius. I also like having the hotter air from the gas furnace when its colder outside. For example during the day right now if the day time temp is above -7C the hp runs and if overnight the temp drops below -7c the furnace kicks on. I can tell what system is running on the app but I can also tell as the hp blower is a set speed and the furnace runs the blower fan at a slower speed. Wow what a difference having even heat in the house - before had to close vents to avoid our laundry room becoming a sauna.

During the cold snap temps dropped to near -20c for a few days and I don't even think the furnace went to second stage but I'm not 100% sure. My ecobee displays stage 1 but I've never seen it display stage 2 yet.

My advice to anyone is to do your homework on sizing and options available and have an idea of what you need before getting quotes. Take your time getting quotes and choosing a contractor. I had quotes that are double the price what I paid and double the size I installed. It's the wild west so the more you know the better. Lots of great info here on RFD - thank you to those who helped me.

Ask away if you have questions.
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tomtomk wrote: Hey @Y2BNE1 , yes I am aware of the MURA. I'm told it's a slightly newer version of the MARB. I also noticed that the MURA is only available with fan coils not furnaces, whereas the MARB is available with either.
Both matchups qualify for the same max rebate of $5,000 under Greener homes or $6500 under the Enbridge HER+ program.
Curious where you are located and who is offering the MURA. I was told by a couple installers that the MURA isn't available yet, however I'm not sure if that's a fact or if they're just trying to clear out the MARBs.
@tomtomk 38MURA & 59TP6
https://forums.redflagdeals.com/canada- ... #p37301416

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