dag

I will assume a three ton is correct size.

How are you heating your home now?

these are my minimum specs for a new HP system. both outside and inside units should be replaced to have a properly matched system.

15 SEER, 12.5+ EER, 9 HSPF
best matching VS air handler
full BTUs in both cooling and heating for your rated size
R-410a refrigerant(same as Puron)
scroll compressor preferred
electronic demand defrost preferred
thermostat with "dehumidify on demand" feature
staged backup heat strips
new and correctly sized refrigerant lineset

you want a thorough inspection of your ductwork system. size, overall condition, supply and return lines, insulation qualities, leak test, etc.

any hot/cold spot issues in your home should be addressed.

I would only use authorized dealers for the various brands that provide quotes. see mfg websites.

I would look at Trane/AmStd,Rheem,Carrier/Bryant.

yes, I would want the VS air handler and the XR15 HP mdl.

Trane makes a 7/12 KW staged heat strip module that I would recommend.

You will need the necessary capacity in your breaker panel service to handle the backup heat strip which is normally placed on a separate circuit.

you do not have natural gas service? or getting rid of propane?

this would be the configuration that I would recommend and it does qualify for fed govt tax credit.

3519776 Active Systems XR15 WEATHERTRON TRANE 4TWR5036E1 4TEE3F40B1 37400 12.70 15.00 36200 9.00 23400

IMO

What is the humidity like in your area in the summer? As much as I would say variable speed is the cat's meow, if you're in a low humidity situation it may not matter.

If you're moving from gas (of some sort) to HP, then it is quite possible you do not have sufficient electrical capacity. This is a Big Deal in that upgrading the service will not come cheap.

tigerdunes - we don't have gas lines in our area. The house is entirely electric. The unit we are replacing uses pure electric heating.

You seem to be down on Lennox. Any particular reason? They are viewed highly by people here.

weedmeister - it is not nearly as dry as you would think here in N. Texas. So, I would say humidity is a problem.

Thanks to both of you for responding.

I would probably go with the trane quote. Seems like most value for money, although the first quote is ok too.

Heat pump will save you money on energy over straight electric or propane.

Natural gas is cheaper to heat with right now when its cold out but probably won't be forever.

dag

how do you heat your home now?

heat strip only?

if so, what size?

It is true I am not a fan of Lennox and don't believe their HPs are a strength within their product line.

Lennox Merit series is low end Lennox. Trane's XR15 is a better unit.

Lennox XP17 is high end Lennox with a nice price.

I will stand with my previous post and recommendations.

IMO

tigerdunes -

Yes, it's heat strips only, 10kw I think. Like I said, it's a 28 year-old unit.

I've got two more bids coming. I think they are both Lennox, though. I will check on getting more from Trane and the others.

Thanks again.

I did have one more estimate:

Goodman DSZC16, with a AEPF3036 air handler, 16SEER, 12.5 EER, 9.75 HSPF for $6335. The estimator didn't think I needed the electric upgrade if I stuck with 10 kw heat strips, only if I went to 15 kw (which is standard on this unit).

dag

the Trane XR15 is a nice unit.

I personally would not have a Goodman.

You are going to save a pile of bucks with a heat pump over straight heat strip heating. I would hate to see your electric bill.

I like the 7/12 KW staged heat strip that Trane offers and that would be my selection. But if your electric panel requires upgrade, then stay with 10KW to avoid that additional cost.

IMO
Good Luck!

Bad news on the electrical upgrade. Cost will be significantly higher than I anticipated - $2500+!

Makes me wonder whether a heat pump is the right choice. If I stay with heat strips (I have a Lennox quote with that set up), the summer energy bill will still be much better. The winter energy biil will not, though.

Seems like no good (i.e., reasonably priced) options.

dag

I don't like to see homeowners taken advantage of or be snookered.

first off you need to find out KW size of your heat strip before you jump to any conclusion or decide against a HP.

for information, one KW equals about 3400 BTUs of heating.

find out about the size and post back.

and who is telling you the upgrade price of $2500 for your breaker panel-electrical contractor or HVAC dealer?

IMO

tigerdunes -

The upgrade quote is from an electrician I've used before and generally trust. I will get another quote before doing anything.

The problem seems to be that the outside unit of the heat pump will pull 60 amps when running. The air handler will pull another 30 when the heat strips are needed. The electric panel has only 60 amps dedicated to the HVAC unit. On top of that, the electric box is on one side of the house and the outside unit is on the other, with the air handler in the middle. With this set up, a lot of the cost is running new electric cable from the box to the air handler and then to the outside unit - within the space between the two stories of our house (first floor unit being replaced).

I replaced a full-electric furnace with a 2.5 ton XR14i a few years ago. I have 200amp service in the house due to the electric furnace. It drew 100a on it's own (it was on a 100amp breaker).

The HP has a breaker requirement of 30amps. The old AC it replaced was 40amps. I find it hard to believe that going from 2.5 tons to 3 tons would double the power required.

The VS blower with electric strips uses (I think) 60amps.

BTW: I had two breakers for the system, one for the AC unit and one for the furnace/blower. Are you saying you have only one?

weedmeister -

I may have flip-flopped the outside and inside amp requirements, but the net result is the same: I have only 60 dedicated to the current unit and I need 90 for the heat pump. One way or another, I would have to have more power available to run the heat pump than I currently have available.

At least that's my understanding of the problem.

its hard to believe you need you upgrade you electrical service if you've been heating your house with just straight electric before.

Maybe just have a smaller electric strip backup. 5 kw maybe. It will dampen the effect of the cold air when heatpump goes into defrost. With your climate the heatpump should be able to handle worst winter days without backup quite possibly.

neohio -

The current set-up does not require the condenser to run for heat, only the air handler (with the heat strips). Right now, it runs one or the other, but not both. The heat pump will need to run both simultaneously exceeding the 60 amps allotted. Therein lies the problem - that and the difficulty in getting the extra juice from one side of the house to the other in between the first and second level of the house.

Keep in mind a brand new high efficiency system is definetly drawing less energy than the old system. If the old system was 10 seer or less and the new one is 15 seer the outside unit will be using significantly less energy. If the old unit is nearly 30 years old it was probably less than 10 seer. I would consider just downsizing on the heatstrips a little to make it economically feasible.

neohio -

One of the HVAC guys said that might be enough juice for the heat pump, but I think the problem also goes to separating the breakers (and the associated electric lines). There is currently have one 60 amp breaker for the unit. With the heat pump (even if 60 amps total is enough - and there are varying opinions about that), they (and the associated lines) have to be broken into two 30 amp breakers. That will still incur a cost.

Again, I'm applying layman's terms to this after talking with several more knowledgeable folks.

I guess the bottomline question is: can you run a 3 ton HP on one 60 amp breaker? If so, how does it work? What is the max heat strips?

You could consider having the heat pump without the electric strips in the furnace. Realistically in your climate you might not have a ton of weather events that force your heatpump to go into defrost when you have a heatpump with demand defrost.

My heatpump has demand defrost. As I write this the outdoor temp is 36 degrees fahrenheit and its been snowing/sleeting. When it was snowing/sleeting it seemed to freeze up quick. Now that its not its not going into defrost as much.

Keep in mind that a heatpump works best at maintaining temps. In mid 30's weather it will go on for a while, then turn off a while. When it turns off it kinda gets a free defrost (assuming out temps are above freezing). If it was running nonstop it would most likely go into defrost more. As it turns off the out door unit will warm up to outside temperatures.

Defrost is probably the only thing you need the heat strips for. Ofcourse, if something happened to your heatpump you would like to have emergency heat. You could get some portable electric heaters for worst case scenario's. You don't happen to have a propane fireplace by chance do you?

"I guess the bottomline question is: can you run a 3 ton HP on one 60 amp breaker?"

As I said, my 2.5 ton is rated for a 30a breaker. The blower would use a 10a breaker if there were NO heat strips. (It is rated for 5.4a, but you can't get a 5.4a breaker.) So you could run BOTH the blower and the HP on 60a with NO heat strips. I can't believe that going from 2.5 tons to 3 tons would increase the power requirement by much, especially since the XR15 is more efficient.

So lets say you could run the whole thing on 40a with NO heat strips. 20a left over would give you 5kw or there abouts of heat strip. This isn't very much.

Personally I'd see about running a separate line to the condenser.

The electrician consensus is that we need to add a separate 30 amp breaker for each heat pump (the house has two, though we're only replacing one). Costly (at least $1500), but necessary.

Final selection for the 3 ton heat pump:

Trane XR15, 4TWR5036E1000A with a 4TEE3F39A1000A air handler, rated 15 SEER/13 EER/ 9 HSPF for $5815; or

Lennox XP17-036-230-50W49 with a CBX40UHV-036 air handler, rated 16.2 SEER/ 13.5 EER/ 9.2 HSPF for $7480.29 - $650 rebate.

The sales guy who bid the Trane also has a Carrier Comfort with a 16/13/9.2 rating for $7865. Seems too high compared with the other two. He also said that Trane does NOT recommend staged heat strips. Reason given: "it will end up costing more in electric use because of a prolonged run time with less heat present." Make any sense or should I insist on staged strips?

I also think that the Lennox bid can be negotiated down some, based on the apparent desperation of the sales guy. If you favor the Trane, is there a price point that the Lennox becomes a better deal?

Thanks again for any advice.

Hi Dag63 - so which system did you end up purchasing? did you upgrade your electricity breaker?

neohio -

We're going with the Trane. And, yes, I will upgrade the electric. Need to add a 30 amp circuit for the heat pump (while they're doing that, we'll also add one for the upstairs unit, though it's not being replaced yet).

They are balking a little about the staged heat strips. They claim that Trane "recommends" 15kw without sequencing. But they will check with their Trane rep about the 7/12kw strips.

Thanks for all of your advice.

sounds good. I would definitely go with staged strip heat.. 15kw strip heat is alot to use everytime your auxiliary comes on.

dag

Trane/AmStd offer two different sizes staged heat strip.

a 7/12 KW mdl

a 10/15 KW mdl

certainly you don't need a 15 KW sgl stg mdl

remember, each KW produces about 3400 BTUs of heat.

IMO

tigerdunes -

Do you have a part number or webpage for those staged heat strips? Then I can give more definitive info to the HVAC guys.

Thanks.

dag

there is a part number but I can't find it. your dealer should call his Trane wholeseller and surely they have a residential specialist who can give him price and availability.I would think for a three ton system, the 7/12 unit would be more than adequate.

IMO