Replacing upstairs HVAC system - am I making a mistake?

[hvtalkuser]

We recently closed on a townhouse in Houston. We have two HVAC systems - one for downstairs (1st & 2nd floors), one for upstairs (3rd floor). We have to do a bunch of other repairs, so decided to use the HVAC guy who did our inspection who was recommended by our general inspector to replace the upstairs AC. We decided to go ahead and replace the ~16 year old furnace also per his suggestion. I already gave him a deposit this past week and he is coming out next week to install both.

When I was trying to decide whether or not to do the furnace also, I posted on several forums and, based on the replies, am having some second thoughts/qualms. I was wondering if you could advise me whether these are valid or not.

The AC and coil are not cooling properly, so definitely need to be replaced. They are both original so ~19 years old.

The HVAC guy is replacing the outside AC component with a Rheem SEER 16, using an Aspen coil (coils are on attic), and install a Rheem 80% furnace (coils are also on attic, previous one is Lennox, not sure efficiency model etc). Some people on the other forum are talking about a J load analysis, about getting a 98% efficient furnace, about getting a 2 stage system. The following is what our HVAC guy said about these things (via text, so I think there are some autocorrect changes):

"Single stage. Less bells and whistles to break down.

Brand furnace. Rheem. Efficiency is 80%. And that's allll you need. 98% style furnaces condensate. It's a different ballgame and no reason for it. You only use them in "foamed homes " or basements where glue vent is impossible"

We do, FWIW, have a multi stage AC for the 1st and 2nd floors. Even if a 2 stage AC is somehow better, I'm not sure how much effect it will have on the 3rd floor (entire townhome is ~2,400 sq ft).

Thank you so much for sharing your thoughts!

EDIT: Also, in case it is helpful, we are in the South, and it is hot and humid ~5-6 months of the year. It does drop to the 30’s or sometimes high 20’s in the wintertime occasionally, but usually not for prolonged periods of time and usually not any colder than that.

[martyinlincoln]

Do you even need a furnace on third floor in Houston? I'd think a heat pump and simple electric air handler should be plenty.

[Artietech]

According the most residential building codes, you will need to have a Manual J Load Calculation done. This is required even for system replacement. As far as the furnace, an 80% is just fine, maybe get a 2 stage?

And to martyinlincoln, I have never had someone with a gas furnace be happy to have it swapped for a heat pump. That heat just isn't the same.

[Makeitcold]

Condensing furnaces are used all over the country in attics, non-foamed homes, etc. I would stick with a heat pump or 80% furnace where you live as there’s no real need for it there, but I find his lack of knowledge concerning. Multi-stage systems are for comfort not so much for savings and are just as reliable as single stage in my opinion. Definitely get a manual J done and don’t take no for an answer, or be uncomfortable. Ask this installer for the AHRI# for that combination. You ONLY will get the rated SEER if the furnace, evap coil, and condenser are an approved match. I don’t think they test them with aftermarket evap coils but I could be wrong but you will NOT get any available rebates for putting in high efficiency equipment without the AHRI#. Kinda late to be asking very important questions if you already paid the guy. Did you sign a contract or is this a “no paper trail” kind of transaction?

[BaldLoonie]

You sure don't need a 98% furnace in Houston!!!!! You will need a furnace with a high efficiency blower motor to get 16 SEER. Rheem has a single stage with "constant torque" motor and a 2 stage with variable speed blower. The latter is more loot but can be hooked with certain thermostats to enhance humidity removal, something I hear is a big thing down your way.

The Manual J is a scientific way to determine what size equipment to get. Many guess and guess big to be safe. Not good. If this is just 1 floor, probably don't need a real big machine especially if there are units on both sides of you.

Just changed a unit for my ex BIL, 2500 sq ft 3 floor townhouse 1 system. 1.5 ton has always cooled OK but most would probably double that just based on the sq ft.

[Mr Bill]

You sure don't need a 98% furnace in Houston!!!!! You will need a furnace with a high efficiency blower motor to get 16 SEER. Rheem has a single stage with "constant torque" motor and a 2 stage with variable speed blower. The latter is more loot but can be hooked with certain thermostats to enhance humidity removal, something I hear is a big thing down your way.

You were reading my mind, 98% in Houston? a waste of money, put the extra money into 2 stage cooling, it will be money a LOT better spent.

[Bazooka Joe]

Ask for this as an example. A AHRI certified reference number to prove a match.

https://www.ahridirectory.org/Home/D...MXaB6qQujL0jCG

Register your system as if system never gets registered the manufacturer warranty decreases significantly.

[hvtalkuser]

Ask for this as an example. A AHRI certified reference number to prove a match.

Register your system as if system never gets registered the manufacturer warranty decreases significantly.

Thanks. I asked whether he will be able to provide an AHRI certified reference number for the equipment that he is installing and he said yes. What do I do with this number? As far as I can tell, there is no longer a federal tax credit, we don't have a state nor local tax, and it appears that our local energy company (CenterPoint Energy, cannot post a link as too new to forum) only offers a rebate to certain contractors as they are not allowed to offer it to customers by law. Just trying to figure out what I can do with the AHRI number.

Also, thanks for the advice - will definitely register the equipment.

[Bazooka Joe]

Thanks. I asked whether he will be able to provide an AHRI certified reference number for the equipment that he is installing and he said yes. What do I do with this number? As far as I can tell, there is no longer a federal tax credit, we don't have a state nor local tax, and it appears that our local energy company (CenterPoint Energy, cannot post a link as too new to forum) only offers a rebate to certain contractors as they are not allowed to offer it to customers by law. Just trying to figure out what I can do with the AHRI number.

Also, thanks for the advice - will definitely register the equipment.

Shows you what your SEER and EER will be ( on paper ) along with proving your getting a matched system and not a Frankenstein system. I hope your not under the impression that whatever the OD unit is listed at, that's the SEER you will get. It's a team effort and the indoor selection determines the final rating. You could be under the assumption and paying for the rated SEER of the OD unit thinking that's what you get. You can easily get even less overall rating. You'll get less, or the rating of the OD unit or even higher. It will state that in the AHRI number. It also keeps the bidding Contractor on their toes when homeowners say I want a system that's AHRI rated.

As an example the certificate sent you says a Trane XR13 but due to the indoor selection it actually gets 14.5 SEER. I could send you a 18 SEER rated OD unit, due to the indoor selection given to the homeowner the AHRI match number was 17.25 SEER.

[hvtalkuser]

Shows you what your SEER and EER will be ( on paper ) along with proving your getting a matched system and not a Frankenstein system. I hope your not under the impression that whatever the OD unit is listed at, that's the SEER you will get. It's a team effort and the indoor selection determines the final rating. You could be under the assumption and paying for the rated SEER of the OD unit thinking that's what you get. You can easily get even less overall rating. You'll get less, or the rating of the OD unit or even higher. It will state that in the AHRI number. It also keeps the bidding Contractor on their toes when homeowners say I want a system that's AHRI rated.

As an example the certificate sent you says a Trane XR13 but due to the indoor selection it actually gets 14.5 SEER. I could send you a 18 SEER rated OD unit, due to the indoor selection given to the homeowner the AHRI match number was 17.25 SEER.

I see. In that case, it is definitely quite helpful to get it - thank you so much for the suggestion!

[Bazooka Joe]

I see. In that case, it is definitely quite helpful to get it - thank you so much for the suggestion!

https://ahridirectory.org/Home/Downl...ixxxc+e8nl1HVu

As an example a 15 SEER rated Carrier that can reach 16 SEER, due to the particular indoor selection the homeowner is getting 14 SEER and a lower EER. Would that bother you that your getting a lower SEER and EER rated equipment than what you thought you where getting and spending your hard earned money on?

Here's the 18 SEER rated OD unit, sorry it's a Trane and not Lennox, shows 17.25 SEER and probably lower EER. Getting less for the money.

https://www.ahridirectory.org/Home/D...Si0E52BXX8qjFh

So ask them to provide the certificate and see what you are paying for. Those numbers are on paper and are hard to achieve in the real world but...if they can't that may fall under a tiny Frankenstein system??

[Mr Bill]

As far as I can tell, there is no longer a federal tax credit, we don't have a state nor local tax, and it appears that our local energy company (CenterPoint Energy, cannot post a link as too new to forum) only offers a rebate to certain contractors as they are not allowed to offer it to customers by law. Just trying to figure out what I can do with the AHRI number.

Also, thanks for the advice - will definitely register the equipment.

We just received this from our salesman today, and we're Ruud dealers.

CenterPoint and Entergy Rebate Programs available all summer long!

Get your share of utility rebates offered through CenterPoint and Entergy by installing AHRI certified high-efficiency air conditioners and heat pump systems. The only in-field requirements for you to earn these incentives are:

• Collect a signature of the homeowner on claim form notifying them of your participation in the program.
• Offer the dealer a portion of the rebate in any amount (Entergy does not require this)
• Take a look at the meter and be sure it is a CenterPoint meter or Entergy meter

After the install, you can complete the claim form and send that along with the AHRI Certificate and homeowner invoice to marketing@centuryac.com. In a few weeks, we’ll issue a credit to your account with the rebate amount. If you are not participating in these programs, you are losing out on your share of these funds! Contact your TM for additional program information or Century Marketing.

[hvtalkuser]

We just received this from our salesman today, and we're Ruud dealers.

CenterPoint and Entergy Rebate Programs available all summer long!

Get your share of utility rebates offered through CenterPoint and Entergy by installing AHRI certified high-efficiency air conditioners and heat pump systems. The only in-field requirements for you to earn these incentives are:

• Collect a signature of the homeowner on claim form notifying them of your participation in the program.
• Offer the dealer a portion of the rebate in any amount (Entergy does not require this)
• Take a look at the meter and be sure it is a CenterPoint meter or Entergy meter

After the install, you can complete the claim form and send that along with the AHRI Certificate and homeowner invoice to marketing@centuryac.com. In a few weeks, we’ll issue a credit to your account with the rebate amount. If you are not participating in these programs, you are losing out on your share of these funds! Contact your TM for additional program information or Century Marketing.

Very helpful. Thanks so much!

[hvtalkuser]

Condensing furnaces are used all over the country in attics, non-foamed homes, etc. I would stick with a heat pump or 80% furnace where you live as there’s no real need for it there, but I find his lack of knowledge concerning. Multi-stage systems are for comfort not so much for savings and are just as reliable as single stage in my opinion. Definitely get a manual J done and don’t take no for an answer, or be uncomfortable. Ask this installer for the AHRI# for that combination. You ONLY will get the rated SEER if the furnace, evap coil, and condenser are an approved match. I don’t think they test them with aftermarket evap coils but I could be wrong but you will NOT get any available rebates for putting in high efficiency equipment without the AHRI#. Kinda late to be asking very important questions if you already paid the guy. Did you sign a contract or is this a “no paper trail” kind of transaction?

There is no specific contract, although he did provide an estimate and we gave a $2k deposit.

He did say he would provide an AHRI #.

Also, we are planning to replace all or most of the 3rd floor windows as well. Would this not affect the manual J calculation?

Re "Kinda late to be asking very important questions if you already paid the guy." - any specific recommendations re being in this situation?

Thanks so much!

[hvtalkuser]

You sure don't need a 98% furnace in Houston!!!!! You will need a furnace with a high efficiency blower motor to get 16 SEER. Rheem has a single stage with "constant torque" motor and a 2 stage with variable speed blower. The latter is more loot but can be hooked with certain thermostats to enhance humidity removal, something I hear is a big thing down your way.

The Manual J is a scientific way to determine what size equipment to get. Many guess and guess big to be safe. Not good. If this is just 1 floor, probably don't need a real big machine especially if there are units on both sides of you.

Just changed a unit for my ex BIL, 2500 sq ft 3 floor townhouse 1 system. 1.5 ton has always cooled OK but most would probably double that just based on the sq ft.

I see. So it looks like our upstairs (3rd floor) unit is currently 2 ton, and third floor area per appraisal is 850 sq ft. We do have 3 3rd floor windows facing east, 1 window facing west, and 6 windows facing south in case that matters. Is the 2 ton unit likely oversized for the 850 sq ft area? (based on your example). Thanks!

[hvtalkuser]

https://ahridirectory.org/Home/Downl...ixxxc+e8nl1HVu

As an example a 15 SEER rated Carrier that can reach 16 SEER, due to the particular indoor selection the homeowner is getting 14 SEER and a lower EER. Would that bother you that your getting a lower SEER and EER rated equipment than what you thought you where getting and spending your hard earned money on?

Here's the 18 SEER rated OD unit, sorry it's a Trane and not Lennox, shows 17.25 SEER and probably lower EER. Getting less for the money.

https://www.ahridirectory.org/Home/D...Si0E52BXX8qjFh

So ask them to provide the certificate and see what you are paying for. Those numbers are on paper and are hard to achieve in the real world but...if they can't that may fall under a tiny Frankenstein system??

Thanks.

AHRI # 201277888

Outdoor Unit: RHEEM RA1624AJ1
Indoor Unit: ASPEN CH36A34+TDR
Furnace: RHEEM R801TA050314MSA

Overall system:
Cooling Capacity (A2) - Single or High Stage (95F), btuh : 24000
SEER : 16.50
EER (A2) - Single or High Stage (95F) : 13.00