I have been an avid reader/participant of some GardenWeb forums (kitchen, bathrooms, appliances), but am a newbie when it comes to HVAC. I'm trying to get up to speed on this area as quickly as possible so I can be somewhat knowledgeable. Our HVAC system is important to me because it's what I consider to be "a big spend", and because we want to get this right, as we hope to live in this house for the next 20+ years. We are doing a major renovation; the house was built in 1962 and is located in the DC metro area. It has a furnace and A/C system that covers the first three floors, and then has baseboard heat and window AC units on the third floor. All ductwork is original to the house, although most of this has already been removed from the first and second floors due to our renovation. I will post as much info as I can about the current systems as soon as I'm able.

Here's info on the 4 floors of the house:

Basement: Approximately 1,200 square feet. This area has a large utility room, bedroom, bathroom, small office and large living area that's L-shaped; but, it eventually will be opened up to one large room, plus the separate utility room.

First floor: After the renovation, this will be approximately 2,400 square feet. This area, along with the second floor, will be our primary living area. It has a living room, dining room, foyer, open kitchen and family room, small study and mudroom. The kitchen and family room sits atop a loggia. Pretty much getting all new ductwork because the only two rooms not being touched are the living and dining rooms.

Second floor: This will be approximately 1,300 square feet. Houses three bedrooms and two baths. Also getting all new ductwork.

Third floor: Approximately 600 square feet (plus about another 150 in insulated attic space). Houses two bedrooms and one bath. This floor will not be used except for guests, and maybe our kids will move up there once they're older. Also getting all new ductwork to tie into systems and get rid of the baseboard head and window AC units.

We are putting in new windows and doors (Marvin Wood Ultimate) in the renovated part of the house. We also plan to put in spray foam insulation.

We received quotes for geothermal and regular HVAC systems. We are considering going with geothermal due to the tax credits (federal, state, county) and because we'll be in the house for a long time. All proposals to date are from the same company. We will get other proposals, but first we want to narrow down choices, figure out what to request, etc.

Here are our options:

1. Go with geothermal. Was quoted two systems, the first covering the basement and first floor, the second covering the second and third floors.

System 1 -
TTV049AGC01ARKS Climate Master Tranquility 27 Two-Stage Geothermal Heat Pump
AFCG2B1 Grundfos Flow Controller
AHK5EC Flow Controller Hose Kit
AFC5F 1.25" PE Socket Fusion
ASP30 High Density Pad
ATP32U04 Climate Master Thermostat
AGL15A Auxiliary/Emergency Heater
HC10 Media Filter (20x25)
Hot water generator included with heat pump

System 2 -
TTS049AGC01CNNS Climate Master Tranquility 27 Two-Stage Geothermal Heat Pump
FV4CNB006T00 Carrier Variable Speed Fan Coil
AHK5EC Flow Controller Hose Kit
AFC5F 1.25" PE Socket Fusion
ASP30 High Desnity Pad
ATP32U04 Climate Master Thermostat
15KW Heat Package
HC10 Media Filter (20x25)
Hot water generator included with heat pump
Emergency drain pan
EZ Trape Condensaet Safety Switch and one Wet Switch
Refrigerant lines, condensate drain lines, control wiring and start up

All three proposals also include: increase the air return to the system, vent kitchen and bath exhaust (we need a MUA system in our county), ground heat exchanger. Electric, plumber and drywall repair will be by others.

Proposal #1 ($66K), includes the two systems above, plus new air trunk/branch lines to the first floor and complete duct system to second and third floors. No ductwork to basement specified.

Proposal #2 ($84K) includes the two systems above, plus air trunk lines to basement and first floor, complete duct system to second and third floors, one new air return to basement and first floor, and puts two zones in for each of the two systems (so 4 zones total, one per floor of the house). The zone system includes: zone equipment controller, user interface, smart sensor, damper control module, outdoor temperature sensor, automatic zone dampers, by-pass damper, control wiring and start up.

Proposal #3 ($77K) includes the two systems above, and is similar to Proposal #2, but there are only two zones (one for each system). The media filter changes to 16x25. This proposal looks like #1 to me, but with the addition of ductwork to the basement.

2. Go with our current HVAC system for the first and second floors, and add a heat pump for the second and third floors.

Proposal #1 ($23K) includes air trunk/branch lines for first floor, no bath/kitchen venting, refrigerant lines, condensate drain lines, control wiring, start up, plus the following for the second and third floors:

FE4ANF005 Carrier Infinity Series, Fan Coil
25HPA636A003 Carrier Performance Series, 16 SEER Heat Pump
15 KW Heat Package
Infinity Controller
HC10 Media Filter (16x25)
Duct system for second and third floors

Proposal #2 ($44K) includes air trunk lines and new air returns to basement and first floor, kitchen and bath exhaust, plus the following for the second and third floors:

25HNB648A003 Carrier Infinity Series 2-Stage Heat Pump
FV4CNB006T00 Carrier Variable Speed Fan Coil
Carrier Infinity Thermostat
15 KW Heat Package
HC10 Media Filter (20x25)
Duct system for second and third floors
Emergency drain pain
EX Trap Condensate Safety Switch and one Wet Switch

And adds two zones in for each of the two systems (so 4 zones total, one per floor of the house). The zone system includes: zone equipment controller, user interface, smart sensor, damper control module, outdoor temperature sensor, automatic zone dampers, by-pass damper, control wiring and start up.

Proposal #3 ($36K) is the same as Proposal #2, but with two zones (one zone for basement and first floor, one zone for second and third floors).

3. Go with all new HVAC systems ($52K).

For basement and first floors:
58MVC080-20 Carrier Infinity Series, 95% AFUE Gas Furnace
24ANB736A003 Carrier Infinity Series, 2-Stage Air Conditioner
Carrier Infinity Thermostat
CNPVP4221ATA Carrier Cased Coil
HC10 Media Filter (16x25)
Air trunk lines to basement, first floor, and new air returns; vent kitchen and bath exhaust

For second and third floors:
25HNB648A003 Carrier Infinity Series, 2-Stage Heat Pump
FV4CNB006T00 Carrier Variable Speed Fan Coil
Carrier Infinity Thermostat
15 KW Heat Package
HC10 Media Tilter (20x25)
Duct system for second and third floors
Emergency drain pan
EX Trap Condensate Safety Switch and one Wet Switch

And adds two zones in for each of the two systems (so 4 zones total, one per floor of the house). The zone system includes: zone equipment controller, user interface, smart sensor, damper control module, outdoor temperature sensor, automatic zone dampers, by-pass damper, control wiring and start up.

My questions:
1. Spray foam insulation will be placed atop the loggia/under the first floor of the kitchen/family room addition. I'm concerned about this floor being cold in the wintertime. We were considering hydronic radiant heat (really to heat the floor) or an electric mat, but our GC has assured us that the iso will be enough. Thoughts??
2. I don't yet have a quote for the spray foam insulation, but should we definitely do this?
3. Would you go with geothermal in our situation? Or would you go with all new systems, or reuse what we have and add a system for the second and third floors?
4. How many zones do you think we need? If cost weren't an issue, we'd love to have one zone per floor. But we don't have an unlimited budget :-) Our GC says he thinks we should zone the basement because of humidity issues in our area. Our architect, however, thinks it's more important to zone the third floor because otherwise it will get pretty hot up in those bedrooms. Although we don't plan to use the third floor space a lot initially, we will have three kids sharing two bedrooms, and I expect some of our kids may move up to the third floor once they're older. Otherwise, this space will be used for guests.
Should we get new ductwork in the basement since we're opening up the space (and the ductwork is old)?
5. I do not see any well drilling costs in any of the proposals. Should this be included?
6. How do these prices look for our area? They seem extremely expensive to me, and we will get more quotes....
7. What should we be asking to narrow down our quotes?
8. Any other advice?

Thanks!

Since you plan to be in this home for 20 plus years geo may make sense. If you were to consider a conventional heat pump I would suggest the Carrier Infinity Greenspeed series.

While you are renovating, I would upgrade all the duct work possible and insulate with Soya based polyurethane spray foam. You will definitely need either an HRV or ERV fresh air exchanger. 1 zone per floor would also be preferable.

If you want a mix of forced air and in-floor radiant look for a triple function geothermal heat pump, forced air heating and cooling, full capacity hot water for in-floor radiant and a desuperheater for domestic hot water.

From what I see in the quote it sounds like they plan to install 1.25in diameter HDPE pipe in the boreholes. I see no indication as to how many feet per ton they plan to drill, whether they plan to connect the boreholes in series or parallel, whether they plan to install separate ground loops for each HP or a combined loop field with variable speed flow centre - all very important factors!

I would also consider the inclusion of an expansion tank in the ground loop circuit and a visual method to check flow rate of the fluid circulating in the ground loops, Blue-White F-410.

http://www.blue-white.com/Products/VariableArea/F-400/acrylictube.asp

Drilling costs should be included, as should the type of antifreeze and concentration.

No mention of Manual J load calcs or design temperatures either...

SR

Do you know the tax credit net cost on the geo units? Have you looked into being able to use all the tax credits in your particular financial situation. Some have AMT issues (I am pretty sure the federal one does not), some have tax liability issues - in my state, the credit can only reduce liability and it has 5 years to do so. Not usually an issue but if you are getting a large credit, then it might be. You also have to do some clever math as the credits aren't additive. For instance, we have combined 65% credit on solar but it really is more like 50% because of the interaction.

What is your electric rate?

I can't imagine not having 4 zones. In my state, it is code. Are you sure in your state it isn't? If you delay, it might become code. Something to consider.

So is the addition on a crawl space? You could probably seal the crawlspace for less than foam and be perfectly comfortable.

Above poster said that you need an HRV - this is a 1962 house. I'm not sure why you would need an HRV unless you were stripping the siding and sheathing of the entire house and putting in foam. I am willing to bet that a 1962 house with a renovation with some foam will leak like a sieve.

Thanks very much for your responses.

- Everyone I've spoken with, and you've confirmed, that one zone per floor makes sense. If I'm missing anything else about "zones", please let me know!

- How much should it cost to go from 2 zones to 4?

- We are definitely going to put in all new ductwork. Is there anything here that I should be aware about or ask for? Any sites (besides GW) to get more knowledge on this area so I can ensure we get the ducts sized properly?

- Good comments on getting more info on the geo wells, piping, etc. Will do.

- Can I get a Manual J done even if the house is under construction? Framing is almost done, but the exterior work is not complete, and so it's open to the elements right now.

- Yes, we have a natural gas furnace and electric AC in the house. It appears that a NG furnace was installed in 2007. The unit is a Lennox Signature Collection, model CX34-62D-6F. We also have an electric hot water heater, AO Smith ProMax Plus, model FCG 75 300. Does it make sense to re-use these or upgrade? Obviously, the furnace will be out if we go with geo.

- Here's a summary of our NG and electricity rates. I hope I'm doing this correctly -- taking the bill amount and dividing by the energy used. Some months may need to be taken out because the numbers are too high/low. Please note that we have not lived in the house, so this is what we were paying for several months before construction commenced. So I would expect actual usage, and thus our bills, to be higher, but I guess that the cost per unit would be somewhat proportional.

Natural Gas
Monthly Charge / Therms Used / All-In Cost Per Therm
$18.06 / 5.1 / $3.54
$16.76 / 5.1 / $3.29
$51.90 / 32.5 / $1.60
$78.53 / 57.7 / $1.36
$339.62 / 314.7 / $1.08
$362.71 / 321.1 / $1.13
$184.41 / 154.8 / $1.19
$81.98 / 60.4 / $1.36
$66.62 / 47.4 / $1.41
$18.45 / 7.1 / $2.60
$16.18 / 5.1 / $3.17
$1.97 average

Electricity
Monthly Charge / KWH Used / All-In Cost Per KWH
$285.18 / 1757 / $0.16
$137.36 / 786 / $0.17
$77.44 / 416 / $0.19
$57.91 / 316 / $0.18
$66.29 / 382 / $0.17
$86.87 / 524 / $0.17
$61.02 / 341 / $0.18
$24.50 / 76 / $0.32
$25.22 / 80 / $0.32
$38.34 / 73 / $0.53
$21.23 / 53 / $0.40
$32.62 / 140 / $0.23
$0.25 average

- It must not be code on my state (MD) to have each floor zoned. Our bids have been for two zones (on per system, one system covering basement and first floor, second system covering second and third floors), or for four zones (running off two systems).

- Thanks for the heads up on the tax credits. My husband is tracking these, so I'll make sure he knows this.

- The addition is on a loggia, not crawl space. So the basement is a walk-out basement, and the loggia will in effect extend the basement, and then the kitchen/family room addition will be above this, and our master bedroom addition above that. It's at the back of the house. Here's an early photo so you get the idea. The house is brick, and the addition will be part brick, part clapboard.

- I am trying to learn what an HRV is, so am looking into this.

- If it's not a good idea to go with spray foam insulation, let me know! Thanks for the info on what type would be good.

- More thoughts on what system to go with, pricing, etc.??

THANKS AGAIN!!

Geo is really good when you don't have NG available and also pretty far north. It is also good when electricity is cheap. You have none of these things. Even with a good COP, NG would be cheaper to heat with. The difference in a/c season is probably only 20% vs a decent new a/c.

Why are you going geo? You pay $1000 a year to heat. With geo it might be $1000 also. It might be more.

I think at $.10 a kwh, the current NG price equals a cost equivalent is at about COP 3.5. At your price, you would need a COP around 6 which is near impossible to reach. Most people are at 4 or 4.5.