OT: Advice on new HVAC

[Cosmos]

The old one is 16 years old. Here in Texas that's ancient. Time to bite the bullet.

I've been putting it off because I hear horror stories about the new Puron R410A systems running constantly and not cooling off as well as the old Freon R22 systems. Plus, they run under higher pressure and result in more breakdowns and service calls. Is it true? Also, do you still need one ton of capacity for every 1,000 s.f.?

Consumer reviews seem to favor systems made by Lennox and American Standard, followed by Trane and Carrier, then comes the rest of the field.

Thanks in advance.

 

[PSUeng]

The old one is 16 years old. Here in Texas that's ancient. Time to bite the bullet.

I've been putting it off because I hear horror stories about the new Puron R410A systems running constantly and not cooling off as well as the old Freon R22 systems. Plus, they run under higher pressure and result in more breakdowns and service calls. Is it true? Also, do you still need one ton of capacity for every 1,000 s.f.?

Consumer reviews seem to favor systems made by Lennox and American Standard, followed by Trane and Carrier, then comes the rest of the field.

Thanks in advance.

here in PA we use 600 sq. ft per ton. If you live in Texas and go 1 ton per 1000 sq.ft. it will run always. I would have no concerns with 410. New refrigerants are soon to hit the market. The new air to air heat pumps are incredible as far as efficiency goes.

 

[PeetzPoolBoy]

The old one is 16 years old. Here in Texas that's ancient. Time to bite the bullet.

I've been putting it off because I hear horror stories about the new Puron R410A systems running constantly and not cooling off as well as the old Freon R22 systems. Plus, they run under higher pressure and result in more breakdowns and service calls. Is it true? Also, do you still need one ton of capacity for every 1,000 s.f.?

Consumer reviews seem to favor systems made by Lennox and American Standard, followed by Trane and Carrier, then comes the rest of the field.

Thanks in advance.

I really like the American Standard equipment. I would use the attached link to get a list of Amer. Standard Factory Certified installers in your area and get multiple opinions and quotes.

https://www.americanstandardair.com/how-to-buy/find-your-dealer.html

As for size, I currently have 2 single-stage 5 ton units and they cycle a bit too much for my liking (they came with the house - I didn't select them). When/if I ever change them out, I'll probably go down to 3 or 4 ton units (2 stage) that will run longer. I would avoid the variable speed compressors, but that's just me.

The amount of tonnage you need will depend on (a) how many "zones" you have in the house, (b) number of stories and (c) how well insulated it is.

 

[LighthouseGolfer]

Good thread, thanks for starting it. I, too, am in the initial research stages. Currently have a 5 ton Lennox that's about 17 y/o. Its a electric heat pump and came with the house when bought it 3 years ago. A number of my neighbors installed Trane's over the past 4 years and really like them. I saw a negative comment about the variable speed above. Why do you recommend against it? The neighbors are lovin them? Thanks for educating the uninformed here.

 

[PeetzPoolBoy]

Good thread, thanks for starting it. I, too, am in the initial research stages. Currently have a 5 ton Lennox that's about 17 y/o. Its a electric heat pump and came with the house when bought it 3 years ago. A number of my neighbors installed Trane's over the past 4 years and really like them. I saw a negative comment about the variable speed above. Why do you recommend against it? The neighbors are lovin them? Thanks for educating the uninformed here.

If/when they need repairs, the variable speed compressor motors are expensive ($$$). The attached article should help explain the differences.

http://www.airconditioningarizona.c...air-conditioner-vs-two-stage-vs-single-speed/

 

[PennStJeff]

If/when they need repairs, the variable speed compressor motors are expensive ($$$). The attached article should help explain the differences.

http://www.airconditioningarizona.c...air-conditioner-vs-two-stage-vs-single-speed/

I opted to replace 1 of my 2 HVAC units last year with the variable speed motor upgrade in the name of comfort (upstairs unit). After a year of use, I can't really detect much of a difference in overall comfort. Only notice it takes about a minute for the fan to get up to full speed. When I replace my second downstairs unit soon, I will stick with the basic stuff.

 

[LK64]

I was in need of a new HAVAC system about 6 years ago and there was a lot of advice from this board on different systems. To tell you the truth it was driving me a little crazy until one poster said, find someone who knows how to install the equipment ( helps on the repair side to have things put in properly ) as the parts are made by a few companies for all the brand names. I looked around in my area and found someone I was very comfortable with after getting recommendations etc. and went with the HAVAC line he carried. Most dealers handle a couple different brands. Haven't been sorry I found the dealer first then the brand.

 

[lilwashnitfan]

The old one is 16 years old. Here in Texas that's ancient. Time to bite the bullet.

I've been putting it off because I hear horror stories about the new Puron R410A systems running constantly and not cooling off as well as the old Freon R22 systems. Plus, they run under higher pressure and result in more breakdowns and service calls. Is it true? Also, do you still need one ton of capacity for every 1,000 s.f.?

Consumer reviews seem to favor systems made by Lennox and American Standard, followed by Trane and Carrier, then comes the rest of the field.

Thanks in advance.

I have a 2 ton carrier and it is great. Electric bill went down $30 a month. I have 1200 square feet uon the main level and 450 in the basement. Best move I made besides my Carrier high efficiency gas furnace.

 

[Nit777]

I have a 2 ton carrier and it is great. Electric bill went down $30 a month. I have 1200 square feet uon the main level and 450 in the basement. Best move I made besides my Carrier high efficiency gas furnace.

Live in an approximate 1,800 SF, single level condo in the Florida panhandle which came with a 5 ton.

Replaced it with a 3 ton Rheem about two years ago and efficiency is better.

You can probably drop from a 5 to a 4 or a 3 and be ok.

 

[PSUTENN1]

I will try to answer some of your questions and concerns;

But first, my resume - I am a licensed HVAC contractor in WNC. Full disclosure, I retired from the USCG, went into HVAC in eastern NC. In 2008 housing market collapsed along with my business. I kept my HVAC business but on a much smaller scale. Now I am a maritime consultant and I help a contractor in WNC where I live, so I'm still up to date on industry standards.

1. There is no such thing as tonnage vs square footage. There's a guess, which is 1 ton for every 650 sgft, but that's BS. You want your installer to do a heat load calculation. It takes into account the insulation in your walls and attic, the condition of doors and windows etc. It all counts. You want to know the biggest factor? It's the condition of your duct work. Is your duct work in an attic or crawl space? I can't tell you how many times a home owner will want a new "more efficient" unit, but pay no attention to the condition of their 30 year old leaky duct work. It makes zero sense. These days, the "efficiency" comes from a much more insulated, and tighter air handling system. The standard now a days is "leak free" duct work.

2. It's true that there are a very few manufacturers of compressors, fan motors and air coils, so the equipment manufactures all use the same stuff. No HVAC equipment supplier builds their own compressors, coils, fan motors etc. They just put it all together.

3. Here's my opinion on equipment - every manufacturer has at least a couple brand names in their line. American Standard = Trane, same unit, different name. Carrier = Payne, Rudd = Rheem. Lennox is Lennox. What's the best money can buy? Well, if you have really big bucks, Maytag makes a 100% stainless steel split system heat pump. But the best brand you would recognize IMHO is Lennox. American Standard and Trane are very good, but I think you pay for the name with those units. A really good compromise between price and quality is a Carrier or Payne. That's what I try to sell customers.

4. Yes, R410A operates at higher pressures, so what? You couldn't by an R22 unit if you wanted to. They are not manufactured. What I noticed is the R410A unit are physically larger, thus the claim that they are more efficient. In fact, they are just unit with a larger capacity to cool. R410A heat and cool much better then old R22.

5. Here's what I see a lot of and I really like, maybe not for Texas, but for colder climates is duel fuel systems. Heat pumps combined with a gas furnace. So the heat pump is the a/c for summer, but in the winter, the HP takes care of heating the home until it gets below freezing outside, then when it's really cold, the gas furnace takes over.

6. Do you have a split system heat pump? For between $6000 to $7000 you can have the equipment replaced. If your duct work is for crap, don't do it, you wont be happy. Bite the bullet, and ask the contactor for a quote to replace the duct work. Insist on at least R24 insulated duct work.

7. Do you live in a two story house? In most states, the energy code requires a thermostat on every floor that can be "occupied". Meaning it has bedroom or bathrooms. That's where all these "zone" systems come in. I'm not a huge fan of zoning, but if it's dome right, it works. I like a separate system for each story of a home.

8. There's a lot more to "heat pumps". A lot. I could write another post all together. Air or water source, make up heat, defrost cycles etc. etc. etc.

9. Mini splits, and of course the crème dela crème, water source heat pumps are a different topic, let me know if you have an interest in those.

 

[Lion78]

A really good compromise between price and quality is a Carrier or Payne. That's what I try to sell customers.

Wouldn't Bryant be in that discussion as well.

 

[PSUTENN1]

"Wouldn't Bryant be in that discussion as well."

Yea - I couldn't think of them all. Bryant is an excellent unit, I put it up there with a Lennox or Trane. I think Carrier recently has bought out Bryant. I know they use they same distributers.

The big boys in HVAC have exclusive deals with certain manufacturers, so no matter what, they are going to sell the customer their manufactures units. Like a car dealership. When I was really in it, I could give the customer the unit of their choice because I had no exclusive relationship with any manufacturer. Those guys got great prices for selling a certain unit though they don't pass that savings on to the customer.

I had really good success with Carrier/Payne Units.

 

[Nittany.Lion]

I will try to answer some of your questions and concerns;

But first, my resume - I am a licensed HVAC contractor in WNC. Full disclosure, I retired from the USCG, went into HVAC in eastern NC. In 2008 housing market collapsed along with my business. I kept my HVAC business but on a much smaller scale. Now I am a maritime consultant and I help a contractor in WNC where I live, so I'm still up to date on industry standards.

1. There is no such thing as tonnage vs square footage. There's a guess, which is 1 ton for every 650 sgft, but that's BS. You want your installer to do a heat load calculation. It takes into account the insulation in your walls and attic, the condition of doors and windows etc. It all counts. You want to know the biggest factor? It's the condition of your duct work. Is your duct work in an attic or crawl space? I can't tell you how many times a home owner will want a new "more efficient" unit, but pay no attention to the condition of their 30 year old leaky duct work. It makes zero sense. These days, the "efficiency" comes from a much more insulated, and tighter air handling system. The standard now a days is "leak free" duct work.

2. It's true that there are a very few manufacturers of compressors, fan motors and air coils, so the equipment manufactures all use the same stuff. No HVAC equipment supplier builds their own compressors, coils, fan motors etc. They just put it all together.

3. Here's my opinion on equipment - every manufacturer has at least a couple brand names in their line. American Standard = Trane, same unit, different name. Carrier = Payne, Rudd = Rheem. Lennox is Lennox. What's the best money can buy? Well, if you have really big bucks, Maytag makes a 100% stainless steel split system heat pump. But the best brand you would recognize IMHO is Lennox. American Standard and Trane are very good, but I think you pay for the name with those units. A really good compromise between price and quality is a Carrier or Payne. That's what I try to sell customers.

4. Yes, R410A operates at higher pressures, so what? You couldn't by an R22 unit if you wanted to. They are not manufactured. What I noticed is the R410A unit are physically larger, thus the claim that they are more efficient. In fact, they are just unit with a larger capacity to cool. R410A heat and cool much better then old R22.

5. Here's what I see a lot of and I really like, maybe not for Texas, but for colder climates is duel fuel systems. Heat pumps combined with a gas furnace. So the heat pump is the a/c for summer, but in the winter, the HP takes care of heating the home until it gets below freezing outside, then when it's really cold, the gas furnace takes over.

6. Do you have a split system heat pump? For between $6000 to $7000 you can have the equipment replaced. If your duct work is for crap, don't do it, you wont be happy. Bite the bullet, and ask the contactor for a quote to replace the duct work. Insist on at least R24 insulated duct work.

7. Do you live in a two story house? In most states, the energy code requires a thermostat on every floor that can be "occupied". Meaning it has bedroom or bathrooms. That's where all these "zone" systems come in. I'm not a huge fan of zoning, but if it's dome right, it works. I like a separate system for each story of a home.

8. There's a lot more to "heat pumps". A lot. I could write another post all together. Air or water source, make up heat, defrost cycles etc. etc. etc.

9. Mini splits, and of course the crème dela crème, water source heat pumps are a different topic, let me know if you have an interest in those.

It seems to me that most residential HVAC contractors wouldn't know a load calc if it bit them in the ass and their eyes glaze over when you mention manual J..... is that an accurate perception?

I just spent some time in FL and looked at some new construction... what do you think of installing ductwork, even properly insulated, in an attic that can reach temperatures of 140 degrees?

Another pet peeve is improper duct sizing and construction which leads excessively noisy systems and hot and cold spots, goes to your point about replacing ductwork, what good does it do to properly size the equipment if the ductwork is poorly designed and built?

Typical ductwork construction where I live (MO) is uninsulated/unsealed sheetmetal (in the basement) and uses enclosed floor joist space for returns and using wall stud cavities for supply to first and second floor.... is that common in your experience?

 

[Carl Spackler]

here in PA we use 600 sq. ft per ton. If you live in Texas and go 1 ton per 1000 sq.ft. it will run always. I would have no concerns with 410. New refrigerants are soon to hit the market. The new air to air heat pumps are incredible as far as efficiency goes.

PSUeng, you seem to know your stuff and we have always had air to air heat pumps of which there was carrying differences in heat, air con. always worked great. How new a unit and in what bottom temp. do new air to air heat pumps actually do a good job of heating? I curious as we have a 25 y.o. unit downstairs that may need to be replaced in our near future. Upstairs unit was replaced six years ago.

 

[PSUTENN1]

"Nittany.Lion, post: 3417208, member: 6110"]It seems to me that most residential HVAC contractors wouldn't know a load calc if it bit them in the ass and their eyes glaze over when you mention manual J..... is that an accurate perception?

I just spent some time in FL and looked at some new construction... what do you think of installing ductwork, even properly insulated, in an attic that can reach temperatures of 140 degrees?

Another pet peeve is improper duct sizing and construction which leads excessively noisy systems and hot and cold spots, goes to your point about replacing ductwork, what good does it do to properly size the equipment if the ductwork is poorly designed and built?

Typical ductwork construction where I live (MO) is uninsulated/unsealed sheetmetal (in the basement) and uses enclosed floor joist space for returns and using wall stud cavities for supply to first and second floor.... is that common in your experience?"



1. It is accurate, but a load calculation is easy. I have a CD, I can do a whole house in 30 minutes. In some areas the inspectors require a load calculation. That's the first sign about the professionalism of the contractor you are hiring. You bring up a point I should have mentioned earlier - contractors. There are TONS of "HVAC Contractors" that have not got a clue, and they're dangerous. Three questions you should ask your contractor;

a. Do you have hold a mechanical license? (ask this because the fly by night guys just pay for someone else to pull the permits for them, run from these people)

b. Can I have some customer references? (call two or three of their former customers, ask them if they're happy with the work)

c. What's the equipment warranty? (it should be 5 years on all parts and 12 months all labor, that standard. Nail your contractor down on this)

Never hire the cheapest, you're hiring a guy who shouldn't be installing HVAC systems and more than likely does not know what he or she is doing. Avoid Joe Bob who used to be in Navy.

The thing about duct work in the attic is this, on start up, it blows some hot air out, but after a few seconds that air clears the duct work and it starts blowing cool air. Sometimes there's no choice, the air handler and duct work have to go in the attic and in the winter that's good. The disadvantage - it's hot in attics in the summer. Honestly once the fan in the air handler has run for 30 seconds that hot airs gone. Duct work in the attic is also better for the mold problem.

Duct sizing is all in the mechanical code, if you have noisy air system, it's because the installer didn't size it correctly and the inspector didn't check it properly. That can be fixed though. A brand new system with poorly insulated and leaky duct work is just a huge waste of money and energy.

Yes. It's very common in older homes to use the floor joists and space between the wall studs as duct for the air return and supply. It does not meet the energy code requirements anymore though. Those floor joists have a huge insulation value. My belief is the more duct work insulation the better. Even return air ducting should be insulated.

 

[LurkerLazarus]

How can you replace duct work, though, without ripping up the entire goddamned house? I have a two-story house with basement, and there's ductwork running all over the place inside the walls. Seems like you'd have to dismantle the whole inside of the house and start over if you replace the ducts in a house like mine.

I'd love to move to a 2-zone system, and have the second floor on a different zone than the first, but it seems like converting to that would cost a fortune with all of the work involved.

 

[PSUTENN1]

How can you replace duct work, though, without ripping up the entire goddamned house? I have a two-story house with basement, and there's ductwork running all over the place inside the walls. Seems like you'd have to dismantle the whole inside of the house and start over if you replace the ducts in a house like mine.

I'd love to move to a 2-zone system, and have the second floor on a different zone than the first, but it seems like converting to that would cost a fortune with all of the work involved.

Do you have an attic and/or a basement?

It’s not inexpensive for sure, but more likely than not it could be done.

If you had an attic I would put the upstairs system up there with the supply
vents in the ceiling.

For the downstairs I would hang the air handler in the basement and the vents would supply through the floor.

 

[LurkerLazarus]

Yes, I do have both an attic and a basement, but how the heck do you get the system from the basement up into the attic? That doesn't seem very straightforward at all.

The thing about the 2-zone system is really all about the AC effectiveness. Heating the house is fine, as is, but per usual the second floor doesn't cool down as much as we'd like when it's really hot. What could you recommend for that situation? I have a 27 yr old house that is about 4000 square feet after additions, with a single 4 ton unit. As typical, basement is really cool, first floor is fine, and second floor is not quite cool enough.

The newer houses today with the 2-zone systems are much better.

 

[PSUTENN1]

There are “zones” and “systems”

In an earlier post I stated I don’t really like “zones” and this is the reason why.

Your home has one system. (What is it by the way, HP or Gas Furnace?) with two “zones”.

More than likely the downstairs is the main zone. Let’s say your trying to cool on a hot day. The way a zone is set up, the down stairs is the master t-stat. As long as your down stairs is calling for cooling, the unit must share the air going to the upstairs and down stairs.

Once the down stairs t-stat is satisfied, some mechanical valves in the duct work open and close and then all the air is supposed to be directed upstairs. It also is supposed to recirculate some of the cooling discharge air back through the unit.

They’re complex and unless the installer is very good and knows his stuff, a zone will not wok correctly.

I would sell you two independent split systems each with their own independent duct work. One for upstairs and one for down stairs.

4000 sqft home, depending on where you live and the condition of the windows, doors and attic insulation, I would guess your looking at 4 to 5 total tons of cooling. All new out the door for 10 to 12.5k.

There are lots of variables.

What kind is system would you prefer and where do you live?

 

[PSUTENN1]

Yes, I do have both an attic and a basement, but how the heck do you get the system from the basement up into the attic? That doesn't seem very straightforward at all.

The thing about the 2-zone system is really all about the AC effectiveness. Heating the house is fine, as is, but per usual the second floor doesn't cool down as much as we'd like when it's really hot. What could you recommend for that situation? I have a 27 yr old house that is about 4000 square feet after additions, with a single 4 ton unit. As typical, basement is really cool, first floor is fine, and second floor is not quite cool enough.

The newer houses today with the 2-zone systems are much better.

 

[LurkerLazarus]

Probably the system you recommend. I'm in western PA, and my current equipment is American Standard. It's 12 years old, and natural gas.

With all of the main ducts being in the basement ceiling and everything coming off of those, is is just a matter of dealing with them, and leaving the rest of the ductwork as is? That wouldn't seem too intrusive.

 

[PSUTENN1]

I get it Laz. I’m sorry. You currently do not have a zoned system. My bad.

Well, a contractor can install a “zones” system using your existing duct work.

It can be done. I’m not a huge fan, but it can be done.

4 tons sounds about right.

 

[LurkerLazarus]

Is it a whole lot more $$ to do as you suggested, and put in two separate systems? At some point, I have to replace the original system anyhow, which is as I said 12 years old.

 

[PSUTENN1]

So, you have central forced air natural gas heat and a/c system in a two story 4000 sqft home. You have too many options for me explain here, and I have a plane to catch at 2:30.

So, I will explain "zones" and what I might recommend for you.

First, it sounds like all you current duct work runs through the walls, even to the upstairs and in the summer it stay hot upstairs and your central heat and a/c system is not "zoned".

First zones - in your house with that rectangular metal duct this wouldn't be easy but here's how it works. There's two mechanical valves installed in the duct work, one in the main supply line to downstairs vents and one in the main supply line to upstairs vents. There is a zone control board that both t-stats send their singles to.

Let's say there are fewer supply vents upstairs then down. When your down stairs t-stat is satisfied, it shuts the valve in the duct work supplying the downstairs vents. Now you have a lot more air flowing upstairs, too much in fact. So to alleviate that a bypass valve is installed in the duct work that opens on an increase of static air pressure to allow a portion of the air flowing upstairs to be redirected to the inlet side of the a/c, thus slowing the flow of air upstairs so it's not noisy, and super cooling the air because a portion of it is flowing through the a/c coil more than once. So theoretically the upstairs should cool super fast, which would satisfy the upstairs t-stat and the unit can shut off. Theoretically. That air that is bypassed back to the air handler is controlled by a weighted valve that is opened by static air pressure. If the installer didn't do his job properly, the system will not function properly. That bypass valve setting is vital.

So, you can apply that to any scenario for zoned systems, one story, two stories it does not matter, that's how "zones" work.

In your situation, to save money, you could isolate your current system duct work to downstairs only and have a second split system heat pump or even gas furnace installed in the attic. The new system would have a main duct trunk line with branch lines that feed all the vents, which would be in the ceiling, and a larger return air filter vent would be installed in a ceiling hallway upstairs. The existing floor vents could be removed and/or covered. It would have it's own thermostat and be independent of the down stairs system.

That's one of many scenarios available to you.

There's so many different options it's impossible to tell you what each might cost, but very rough estimate, if you went with two 80,000 btu gas furnaces and two 2 ton a/c, with all new duct work in the basement and in the attic, I think you would be looking at 10 to 12.5k.

 

[LurkerLazarus]

Thanks so much. You've given me a lot to think about!

 

[PSUeng]

PSUeng, you seem to know your stuff and we have always had air to air heat pumps of which there was carrying differences in heat, air con. always worked great. How new a unit and in what bottom temp. do new air to air heat pumps actually do a good job of heating? I curious as we have a 25 y.o. unit downstairs that may need to be replaced in our near future. Upstairs unit was replaced six years ago.

The new units can go down to 15 degrees but you start losing heating capacity. As others have said depending on where you live requirements change. In some locations you need to design your system for the heating load instead of the cooling load. This may make the system larger then needed for cooling, causing the compressor to cycle more. This should not be a problem if you go with a variable refrigerant flow system or a 2 stage unit. I do mostly commercial work so small system are not my forte. You can download loads programs for free if just looking for block loads.

 

[bar2ski]

"Wouldn't Bryant be in that discussion as well."

Yea - I couldn't think of them all. Bryant is an excellent unit, I put it up there with a Lennox or Trane. I think Carrier recently has bought out Bryant. I know they use they same distributers.

The big boys in HVAC have exclusive deals with certain manufacturers, so no matter what, they are going to sell the customer their manufactures units. Like a car dealership. When I was really in it, I could give the customer the unit of their choice because I had no exclusive relationship with any manufacturer. Those guys got great prices for selling a certain unit though they don't pass that savings on to the customer.

I had really good success with Carrier/Payne Units.

I can recommend Payne. My son in laws cousin is in HVAC and recommended Payne. Same components , lower price because of the name. I'm fact the air condenser unit has Payne on it and the furnace has Carrier. 8 years with no service except cleaning. Great unit.

 

[LurkerLazarus]

This is a great ****ing board.

 

[PSUeng]

There are “zones” and “systems”

In an earlier post I stated I don’t really like “zones” and this is the reason why.

Your home has one system. (What is it by the way, HP or Gas Furnace?) with two “zones”.

More than likely the downstairs is the main zone. Let’s say your trying to cool on a hot day. The way a zone is set up, the down stairs is the master t-stat. As long as your down stairs is calling for cooling, the unit must share the air going to the upstairs and down stairs.

Once the down stairs t-stat is satisfied, some mechanical valves in the duct work open and close and then all the air is supposed to be directed upstairs. It also is supposed to recirculate some of the cooling discharge air back through the unit.

They’re complex and unless the installer is very good and knows his stuff, a zone will not wok correctly.

I would sell you two independent split systems each with their own independent duct work. One for upstairs and one for down stairs.

4000 sqft home, depending on where you live and the condition of the windows, doors and attic insulation, I would guess your looking at 4 to 5 total tons of cooling. All new out the door for 10 to 12.5k.

There are lots of variables.

What kind is system would you prefer and where do you live?

instead of two different system, why not multiple AHU and one variable flow condensing unit. also , as efficiency goes ductless system work well. I would suggest a ductless system instead of new ductwork.

 

[Carl Spackler]

The new units can go down to 15 degrees but you start losing heating capacity. As others have said depending on where you live requirements change. In some locations you need to design your system for the heating load instead of the cooling load. This may make the system larger then needed for cooling, causing the compressor to cycle more. This should not be a problem if you go with a variable refrigerant flow system or a 2 stage unit. I do mostly commercial work so small system are not my forte. You can download loads programs for free if just looking for block loads.

Thank you for the info and advice. I'll keep it in mind as our downstairs unit is a 1992 model, works well but have to think its days are numbered. We were told that, as heating is our primary concern, a propane aux. unit comes with the premium unit whereby we could us it for axillary heat when temps. fall below the efficient heating range of the air to air system. Right now we use an insert but that has to be fed constantly and watched. Plus, should be not be at home most of the time we end up back to the emergency heat setting which causes the electric meter to spin like a top and the dollars fly out the proverbial window.

AND, our ducts in the chilly basement are metal causing a great loss of heat produced, quite inefficient. Ductless has its appeal to me in our situation.

 

[PSUeng]

Thank you for the info and advice. I'll keep it in mind as our downstairs unit is a 1992 model, works well but have to think its days are numbered. We were told that, as heating is our primary concern, a propane aux. unit comes with the premium unit whereby we could us it for axillary heat when temps. fall below the efficient heating range of the air to air system. Right now we use an insert but that has to be fed constantly and watched. Plus, should be not be at home most of the time we end up back to the emergency heat setting which causes the electric meter to spin like a top and the dollars fly out the proverbial window.

AND, our ducts in the chilly basement are metal causing a great loss of heat produced, quite inefficient. Ductless has its appeal to me in our situation.

you can get low temp package that will reduce units down to 0 or lower. elec is the normal backup. how often does it get below 15 in your area. the new unit will be much cheaper to run. with a 25 year old unit, I would consider replacing it. good luck

 

[Carl Spackler]

you can get low temp package that will reduce units down to 0 or lower. elec is the normal backup. how often does it get below 15 in your area. the new unit will be much cheaper to run. with a 25 year old unit, I would consider replacing it. good luck

Our lowest was -9 on New Years Day, North Central Ohio. You say there is a package that electrically lowers the capacity of the unit or am I misunderstanding you. The dealer noted the gas backup. Yes, we know the unit is not as efficient as a newer model but you know, limited income and replacements are sometimes a tough choice. Anyway, the notes you presented are welcome from a layman's standpoint, thanks.

 

[ftlpsu]

"Nittany.Lion, post: 3417208, member: 6110"]It seems to me that most residential HVAC contractors wouldn't know a load calc if it bit them in the ass and their eyes glaze over when you mention manual J..... is that an accurate perception?

I just spent some time in FL and looked at some new construction... what do you think of installing ductwork, even properly insulated, in an attic that can reach temperatures of 140 degrees?

Another pet peeve is improper duct sizing and construction which leads excessively noisy systems and hot and cold spots, goes to your point about replacing ductwork, what good does it do to properly size the equipment if the ductwork is poorly designed and built?

Typical ductwork construction where I live (MO) is uninsulated/unsealed sheetmetal (in the basement) and uses enclosed floor joist space for returns and using wall stud cavities for supply to first and second floor.... is that common in your experience?"



1. It is accurate, but a load calculation is easy. I have a CD, I can do a whole house in 30 minutes. In some areas the inspectors require a load calculation. That's the first sign about the professionalism of the contractor you are hiring. You bring up a point I should have mentioned earlier - contractors. There are TONS of "HVAC Contractors" that have not got a clue, and they're dangerous. Three questions you should ask your contractor;

a. Do you have hold a mechanical license? (ask this because the fly by night guys just pay for someone else to pull the permits for them, run from these people)

b. Can I have some customer references? (call two or three of their former customers, ask them if they're happy with the work)

c. What's the equipment warranty? (it should be 5 years on all parts and 12 months all labor, that standard. Nail your contractor down on this)

Never hire the cheapest, you're hiring a guy who shouldn't be installing HVAC systems and more than likely does not know what he or she is doing. Avoid Joe Bob who used to be in Navy.

The thing about duct work in the attic is this, on start up, it blows some hot air out, but after a few seconds that air clears the duct work and it starts blowing cool air. Sometimes there's no choice, the air handler and duct work have to go in the attic and in the winter that's good. The disadvantage - it's hot in attics in the summer. Honestly once the fan in the air handler has run for 30 seconds that hot airs gone. Duct work in the attic is also better for the mold problem.

Duct sizing is all in the mechanical code, if you have noisy air system, it's because the installer didn't size it correctly and the inspector didn't check it properly. That can be fixed though. A brand new system with poorly insulated and leaky duct work is just a huge waste of money and energy.

Yes. It's very common in older homes to use the floor joists and space between the wall studs as duct for the air return and supply. It does not meet the energy code requirements anymore though. Those floor joists have a huge insulation value. My belief is the more duct work insulation the better. Even return air ducting should be insulated.

100% accurate--did my own research 2 yrs ago did a proactive replacement for 2 original Rheem's that were 16 yrs old. Chose Lennox Elite series SEER 16-made and assembled in IOWA. Did research on Carrier-Trane etc. chose Lennox. My Electric bill dropped $40/month. Had a great install team and it has been flawless-very happy.

 

[Cosmos]

AS a PSA, I wanted to put out an update on my HVAC search...
https://bwi.forums.rivals.com/threads/ot-advice-on-new-hvac.205827/

Recently, I put out a solicitation on Angie's List asking for a new unit plus a load test per PSUTenn1's recommendations (attached). In the solicitation I stipulate, "If you don't want to do a load test then don't bother answering." Sure enough, and to Nittany.Lion's point, most don't want to perform a load test. They just want to do the standard "change out" which relies on charts and graphs provided by either manufacturers and/or the trade group. But that doesn't take into account your house's unique characteristics much less improvements made since your last HVAC install to include, in my case, new doors and windows. As a result of this stipulation only 3 of 12 contractors answered my solicitation! And one politely bowed out after "talking to his techs." And so my search continues for good contractors who will do the 'Manual J' load test.

Note: I limited my solicitation to HVAC contractors having an A to B review rating of 95% or greater on Angie's List. Two of the 12 chosen I've done business with before. They are reputable.

Anyway, I'll let you know how it goes. As a PSA.
I hope to get my HVAC system replaced before the Spring rush hits down here in Texas.

I thank you.

 

[91Joe95]

AS a PSA, I wanted to put out an update on my HVAC search...
https://bwi.forums.rivals.com/threads/ot-advice-on-new-hvac.205827/

Recently, I put out a solicitation on Angie's List asking for a new unit plus a load test per PSUTenn1's recommendations (attached). In the solicitation I stipulate, "If you don't want to do a load test then don't bother answering." Sure enough, and to Nittany.Lion's point, most don't want to perform a load test. They just want to do the standard "change out" which relies on charts and graphs provided by either manufacturers and/or the trade group. But that doesn't take into account your house's unique characteristics much less improvements made since your last HVAC install to include, in my case, new doors and windows. As a result of this stipulation only 3 of 12 contractors answered my solicitation! And one politely bowed out after "talking to his techs." And so my search continues for good contractors who will do the 'Manual J' load test.

Note: I limited my solicitation to HVAC contractors having an A to B review rating of 95% or greater on Angie's List. Two of the 12 chosen I've done business with before. They are reputable.

Anyway, I'll let you know how it goes. As a PSA.
I hope to get my HVAC system replaced before the Spring rush hits down here in Texas.

I thank you.

Inquiring minds on this board are definitely interested in how you make out.

 

[PeetzPoolBoy]

I hope to get my HVAC system replaced before the Spring rush hits down here in Texas.

Now is actually a good time to replace your unit before the HVAC contractors get busy again and raise their prices. Last week I replaced one of my R-22 5 ton units. Pricing is better and the installers aren't having to sweat to death in the attic connecting the coil, plenums etc...

 

[Pinkhippo PeanutButter]

Replacing my heat pump due to leaks. Some manufacturers have switched to aluminum coils (Trane).

My knowledge of materials says that may be less corrosion. But copper is better at heart transfer. I assume though that the system is designed to work with the materials they choose.

Which is truly more reliable? My current system is failing by leaks.

Second question is also reliability. I am thinking to buy a lower efficiency unit this time, actually, as it seems to me that the high efficiency unit I bought last time probably is harder to repair too (More & more expensive components).

Bottom line is reliability. My unit has been on emergency\backup heat for a month and a half, heating well but I have no warning anything is wrong til I see massive electrical bills.

 

[Pinkhippo PeanutButter]

Replacing my heat pump due to leaks. Some manufacturers have switched to aluminum coils (Trane).

My knowledge of materials says that may be less corrosion. But copper is better at heart transfer. I assume though that the system is designed to work with the materials they choose.

Which is truly more reliable? My current system is failing by leaks.

Second question is also reliability. I am thinking to buy a lower efficiency unit this time, actually, as it seems to me that the high efficiency unit I bought last time probably is harder to repair too (More & more expensive components).

Bottom line is reliability. My unit has been on emergency\backup heat for a month and a half, heating well but I have no warning anything is wrong til I see massive electrical bills.

 

[Nitwit]

The old one is 16 years old. Here in Texas that's ancient. Time to bite the bullet.

I've been putting it off because I hear horror stories about the new Puron R410A systems running constantly and not cooling off as well as the old Freon R22 systems. Plus, they run under higher pressure and result in more breakdowns and service calls. Is it true? Also, do you still need one ton of capacity for every 1,000 s.f.?

Consumer reviews seem to favor systems made by Lennox and American Standard, followed by Trane and Carrier, then comes the rest of the field.

Thanks in advance.

Did you consider York? I got quotes today on 3 different systems to replace my central air (4 ton) and gas furnace. The York was a few thousand cheaper then Carrier with almost identical specifications, the main difference was that the Carrier furnace was two stage, and the York 1. Both come with a variable speed blower. The Carrier uses their own thermostat, and the York uses Honeywell. Both were internet enabled to allow remote programming and usage through a phone ap. Seer ratings for both are 16, and warrantees were identical. These were from the same company which has been servicing my current equipment and they are very reliable and responsive. The price was lower than some of my neighbors paid for American Standard. Thanks

 

[PSUSignore]

Duct sizing is all in the mechanical code, if you have noisy air system, it's because the installer didn't size it correctly and the inspector didn't check it properly. That can be fixed though. A brand new system with poorly insulated and leaky duct work is just a huge waste of money and energy.

Hijacking this thread, because I have a noisy furnace and this is one of my biggest pet peeves about my home. My furnace is in a hallway and it can be heard from every room in the house. The hallway is open to the living areas and causes inconveniences like having to increase the TV volume when it's on, for example. What steps can I take to fix this? I have a small 1500 sq. ft. single story home in Texas. I believe existing duct work runs in the attic. My home, like most in central Texas, does not have a basement.

I had one person tell me it's because I have an return vent and cabinet directly under the furnace and there is no ducting between the return and furnace, which causes the noise to come right out of the return vent and into the house. While this is true about how the noise can escape, I don't know if him suggesting moving the return to a different location and putting in some ducting is the proper solution.