Replacing AC with HP

[winksu]

With natural gas prices so unpredictable, I’m looking for a more consistent means of heating my home (2500 sq ft two story with 1000 sq ft finished basement). My current AC (4 ton contractor grade Carrier—10 SEER) is 13 years old and I feel is close to the end of its life. Additionally, our local overall electric rates are going up by 20% but a 30% discount is given Sept - April with a heat pump ($150 savings/year based on current usage). I’ve decided that it’s the right time to make the switch. My heater is a 13 year old Carrier single stage 80% efficient. I plan on staying in my home for at least 10 more years.

I live in what’s referred to as the Northland of Kansas City. I have received estimates from 3 local installers (Bryant, Amana, York) and 1 metro wide (Trane, Everest/Goodman). The three estimates from the local installers have been within $300—the metro dealer was $700 more for the Everest when compared to the Amana (which I’m assuming are identical because they are both made by Goodman and have the same SEER). I have one more estimate scheduled from a local Lennox dealer. I’m currently leaning towards the Bryant because: 1) I’m comfortable with the company because I’ve used them in the past to service my current equipment, 2) They are the only local installer that I’ve gotten an estimate from with a NATE heat pump certification, and 3) Was the only installer that indicated they did any analysis on the optimal SEER with my equipment—told me that the 14 SEER unit was actually more efficient than their 15 SEER unit.

1) How important is the NATE certification? One of the non-certified installers has been in business over 30 years. Is the company or individual given the certification?

2) I heat my basement with a pellet stove and it’s naturally cool in the summer so I have all the supply vents closed. The contractor that finished the basement didn’t put in any return air ducts—he stated that it brought too much moisture into the basement. After a couple of years, I know that I need to add returns. There are two problem areas: A rec room where water drips off a supply vent at the beginning of the cooling season and an office area that is static/stagnant and sometimes gets excessively warm because of the computer equipment. The one other large room in the basement doesn’t seem to have a problem. All the installers agree that I need returns in all three rooms. I’m not comfortable with these recommendations because they were made on the spot without any analysis.

I’ve read that you don’t want to create a negative pressure environment in the basement. One of the contractors stated that as long as the returns weren’t in the same room as the flue, I would be OK. Is he correct?

Knowing that air is going to take the path of least resistance, by adding too many returns in the basement will it be robbing too much return air from the upstairs areas?

3) The York dealer is pushing complete replacement with a 15 SEER Heat Pump and a 80% two stage heater. The basic argument is that the comfort level would be better, the reliability of having a newer unit, and a small increase in efficiency--York estimates that a two stage with variable speed fan is 15% more efficient than a standard 80%.

Is it crazy to replace an existing 80% with an 80%?

It’s been indicated that I’m limited to a 15 SEER unit because of my existing single stage furnace. If I do a complete replacement, should I bite the bullet and go for higher SEER and AFUE?

Would an option be to get a heat pump that will integrate with a two stage heater now with the anticipation of replacing the heater at some point in the future?

4) Reviewing the Carrier and Bryant websites (both owned by UTX) the units offered look very similar. Is there any real difference between the two?

5) I currently have a 1” electrostatic filter and I’d like to upgrade. All of the installers are pushing a 4-5” filter over an electronic air cleaner. They all state that the electronic filters don’t do a very good job although posted stats on the internet seem to disagree. I don’t like the idea of paying $70 annually on replacement filters when the electronic is washable. Are electronic filters effective?

6) The Bryant installer is proposing to use an N coil as opposed to the more standard A coil. I couldn’t find any information on what goes into the selection of a coil design. My ‘guess’ is that the N coil is more compact vertically. The only concern I have with the Bryant N coil is that it doesn’t “allow for easy inspection and cleaning from the front of the unit”. Any comments on N vs. A coils?

7) Every estimate has been for a 4 ton unit because that's what I currently have. No one has done an analysis to see if that's the correct size. Should they have?

Thanks in advance.

[totaleclipse]

1. NATE is a good thing, however there are a lot of good techs out there that are not certifyed for any number of reasons.
2. Basements are few and far between here, so I am going to leave this one to someone else.
3. If you are going to go with a dual fuel set-up, you will not be running the furnace all the time, and when the furnace runs due to low outdoor temps, it will run in low fire and try to heat the house without switching to high fire. If it is unable to heat the house on low fire in a sertain period, it will switch to high fire which is roughly the same as what your existing furnace runs at all the time.
4. I dont think so, but I dont do much with Carrier/Bryant.
5. IMO a 4 or 5" media filter is much better than a electro static filter. The media requires changing once a year, done. The electro static requires mounthly cleanings, produce ozone, and dont filter the air very well. Well worth the cost of the replacement filter, especally when you figure in time and materials (water and cleaner) to clean the other.
6. Again, dont do much with Carrier/Bryant.
7. YES.

A few things to consider. You need to make sure your house has at least a 200A service and additional breaker locations for the extra power the air handler requires over a furnace. Hopefully the contractors looked into this, but this is something a sales man can overlook as they are just trying to sell a box without consideration of what the requirement are to put it in. Also, if your house is not insulated, or insulated poorly, I would recommend you look into upgrading that as a heat pump does not produce air as hot as a furnace does.

[jkc]

Carrier and Briant are basiclly the same, the variable speed motor will definately make a big differance in comfort and effincy, you cant have too much return and will not create negative pressure unless you do not have supply air in the same room. I have been told that to get 15 seer or higher you have to have variable speed blower. In my house I plan to go with Carrier Infinity with 90+ furnace and 2 speed 17 seer heat pump. Bryant has the same type system but I don't remember what they call theirs ( I am service tech for Carrier dealer).

[allstar08]

I will say this, in this day and age we should be pushing fo 90%+ furnaces on new installs and retro fits. Replacing an 80% with an 80% when you are worried about your bills is bad form.
I must admit in my area, Seattle, that dual fuel is becomming more popular with rising gas and electric rates. I will always give a customer that option.
A 95%+ modulating furnace with a heat pump, and with the rebates that are offered today, will pay itself off soon enough, even sooner if rates keep rising the way they have been.
In a perfect world we would manual J every house we looked at, but in this competitive market we just ask the question," are you happy with the way this system cools your house?" If you are we assumme that the system is sized right for your home. I know assumming can get you introuble from time to time, but in most cases it works well.
Nate certification is cool to have, but a good reputation, and BBB membership, and years of expertise are better.
I loved and pushed electronic and electrostatic filters for years, but you know what, a media filter provides the same, and even better performance in most cases, and best of all it is easier to remember to change your filter once a year than once a month. One return in the basement usually does the trick.
Good luck

[beenthere]

With natural gas prices so unpredictable, I’m looking for a more consistent means of heating my home (2500 sq ft two story with 1000 sq ft finished basement). My current AC (4 ton contractor grade Carrier—10 SEER) is 13 years old and I feel is close to the end of its life. Additionally, our local overall electric rates are going up by 20% but a 30% discount is given Sept - April with a heat pump ($150 savings/year based on current usage). I’ve decided that it’s the right time to make the switch. My heater is a 13 year old Carrier single stage 80% efficient. I plan on staying in my home for at least 10 more years.

I live in what’s referred to as the Northland of Kansas City. I have received estimates from 3 local installers (Bryant, Amana, York) and 1 metro wide (Trane, Everest/Goodman). The three estimates from the local installers have been within $300—the metro dealer was $700 more for the Everest when compared to the Amana (which I’m assuming are identical because they are both made by Goodman and have the same SEER). I have one more estimate scheduled from a local Lennox dealer. I’m currently leaning towards the Bryant because: 1) I’m comfortable with the company because I’ve used them in the past to service my current equipment, 2) They are the only local installer that I’ve gotten an estimate from with a NATE heat pump certification, and 3) Was the only installer that indicated they did any analysis on the optimal SEER with my equipment—told me that the 14 SEER unit was actually more efficient than their 15 SEER unit.

1) How important is the NATE certification? One of the non-certified installers has been in business over 30 years. Is the company or individual given the certification?


Its not. Nate is the idividual not the company.

2) Returns in the basement could help heat from the pellet stove heat the rest of your house bettter.

I’ve read that you don’t want to create a negative pressure environment in the basement. One of the contractors stated that as long as the returns weren’t in the same room as the flue, I would be OK. Is he correct?


Would have to examine your basement to know.

Knowing that air is going to take the path of least resistance, by adding too many returns in the basement will it be robbing too much return air from the upstairs areas?

No, if your putting air into rooms upstairs, then the returns for upstairs will bring back that same amount of air.

3) The York dealer is pushing complete replacement with a 15 SEER Heat Pump and a 80% two stage heater. The basic argument is that the comfort level would be better, the reliability of having a newer unit, and a small increase in efficiency--York estimates that a two stage with variable speed fan is 15% more efficient than a standard 80%.

A 2 stage furnace is no more efficient then a single stage of the same AFUE rating. But comfort is better.

If he's talking about the Affinity YZE model, you want a VS blower, so a new furnace is what you need to do.



It’s been indicated that I’m limited to a 15 SEER unit because of my existing single stage furnace. If I do a complete replacement, should I bite the bullet and go for higher SEER and AFUE?

15 SEER, and 90%+ AFUE

Would an option be to get a heat pump that will integrate with a two stage heater now with the anticipation of replacing the heater at some point in the future?

Its a poor option, as you won't get the full benifit of the 2 stage heat pumps.

4) Reviewing the Carrier and Bryant websites (both owned by UTX) the units offered look very similar. Is there any real difference between the two?

Just the name.

5) I currently have a 1” electrostatic filter and I’d like to upgrade. All of the installers are pushing a 4-5” filter over an electronic air cleaner. They all state that the electronic filters don’t do a very good job although posted stats on the internet seem to disagree. I don’t like the idea of paying $70 annually on replacement filters when the electronic is washable. Are electronic filters effective?

Electro static filters are very restrictive, and slow down your air flow.

The media may have to be changed twice a year, but its easier to do that then, clean an electronic every 30 days, and have to wait till its dry to put it back in.

6) The Bryant installer is proposing to use an N coil as opposed to the more standard A coil. I couldn’t find any information on what goes into the selection of a coil design. My ‘guess’ is that the N coil is more compact vertically. The only concern I have with the Bryant N coil is that it doesn’t “allow for easy inspection and cleaning from the front of the unit”. Any comments on N vs. A coils?



Not up on Carrier coils.

7) Every estimate has been for a 4 ton unit because that's what I currently have. No one has done an analysis to see if that's the correct size. Should they have?


It would be best if they did.

If it comes out to 3.5 tons, and you want a 2 stage het pump, you would still have to use a 4 ton, because 2 stage units are not made in half ton sizies.
You may have a hard time finding a company that will do a load calc though.

Thanks in advance.

Click on the hvac calc link, pay the 50 dollar fee, and you can do your own, and then ask questions about your results here.

[dngtig]

Not all electronic air cleaners are created equally. April Aire model 5000 has been rated by consumer reports to work better than the rest. I have heard good things about the trane clean effects. Those all have a replaceable filter media in them. The older style electronic air cleaners without filter media in them are garbage in my opinion. The April Aire 2600 or Trion Air Bear are also good relaceable filters.

[heatpumpguru]

I put in 95%V/S and 2 stage heat pump due to FUEL is not getting any cheaper and I am not moving.

[winksu]

Thanks for the responses.

You need to make sure your house has at least a 200A service and additional breaker locations for the extra power the air handler requires over a furnace.

The house has 200A and there is 50A going to the AC and 15 to the furnace. By additional breaker locations do you mean unused locations on the breaker box?

Since you brought up electricity, I remembered another question. Should the lights in my house dim when my neighbors AC kicks on? They do just briefly...

The media requires changing once a year, done.

best of all it is easier to remember to change your filter once a year than once a month

So far the installers that I’ve talked to stated that they need to be changed twice a year. Are they just trying to drum up repeat business?


Now for a stupid question: If I decide to replace the furnace, what will happen to the old furnace? It still works, seems like a waste to dispose of it.

[beenthere]

Your lights shouldn't dim when the neighbors a/c starts up.
Call the power company.
Not uncommon to have to change the media twice a year.

Your old furnace will most likely be sent to the salvage yard.

No need to up grade your panel box because of duel fuel.

[winksu]

you cant have too much return and will not create negative pressure unless you do not have supply air in the same room

Currently, I have all the supply vents closed in the basement. In the summer it would get too cold. In the winter, I heat most of the basement with a pellet stove, but there is one room that is cooler that I could open.

Will keeping all the supply vents closed with a single return cause a problem? Would an option be to cover the return when all the supply vents are closed?