Are you sure the Amana dealer even did a load calc? 4 tons seems like too much for a well insulated house of that size, the Trane guy's 2.5 ton unit is more in line with what I'd expect. So far I'm liking the Trane quote better, though I'd caution you that it takes a good contractor to get zoning right. How big of a furnace is the Trane dealer planning to put in?

If you decide to go with less expensive equipment to save costs, I would go cheaper on the outdoor unit rather than the indoor unit. I would want to keep the variable speed blowers, and I would avoid the AMH95 furnace because it has 2 stages, but is only compatible with a single stage thermostat. Your only option is to use the built in timer on the board.

On the Trane AC condenser, I would want the two stage XR17 3 ton AC model.

What size XV95 furnace, 60 or 80 K size?

Did I miss this-nat gas fuel for heating? Pls confirm.

IMO

hvtech42/tigerdunes - I still have to scope the Trane dealer. We were supposed to talk today and I plan to talk with him tomorrow. I did find my load calculations from the Amana dealer which I will include below. tiger - you asked about the btu's of the furnace and that is one question I have for the Trane dealer. I thought it was 60k when I initially read the quote but the second time reviewing it, I wasnt sure. As for fuel type, we are right in the middle of the Marcellus Shale vein and I am banking on natural gas being pretty cheap so most of my appliances will be gas. hvtech - i do like the sound of a variable speed from what i read and are being told. I am also okay with spending a little more as long as it is justifiable. Here are the load calculations from the Amana dealer:

Design Conditions: Pittsburgh (just north of washington,pa)
Indoor
Summer Temp: 75
Winter Temp: 72
Relative Humidity: 50
Outdoor
Summer Temp: 90
Winter Temp: 0
Summer grains of moisture: 88
Daily temp range: medium
Sensible Gain (btuh): 37087
Latent Gain (btuh): 7650
Total Heat Gain (btuh): 44737 (3.5 tons)
Total Heat Loss (btuh): 112120

If you need to see the paper, I can scan and attach.

As for the York dealer, I spoke with him on the way home. He was still adamant on his original design which was to do two smaller systems to operate the first and second floors separately. The second floor furnace was going to go right onto the second floor in a dead space cavity between two rooms. He included an ERV and whole house humidifier as well.

hvtech42 - this may alleviate the risk you mentioned of not properly setting up zoning but it seemed a little overkill to be putting two systems in. The second and first floor share no space other than the stairs (no atrium or foyer).

the scary thing about the York dealer is that his price for two systems was cheaper than other dealers single systems. So i am either getting high prices on a single system or Yorks pricing is out of wack. I will list his specs when I get back to work tomorrow morning.

Load calculation summary:

Total Heat Gain (btuh): 44737 (3.5 tons)
Total Heat Loss (btuh): 112120

I would believe the heat gain if this were a typical 2X4 construction with R-13 insulation in the walls and R-30 in the attic. Your house has much higher insulation values so I would expect to be under 3 tons. The summer design temperature for Pittsburgh is 86 degrees F. You have some margin in the calculation.

The heat loss of 112,120 BTUs is wrong. Is this a typo mistake?

mike_home - I have uploaded the load calculations from the Amana dealer. I hope this helps.

This post was edited by downonthefarm on Wed, Oct 15, 14 at 11:40

Do you also have the load calc from the Trane dealer so we can compare the inputs?

BTW I would highly recommend that you edit your name/address out of that picture.

hvtech - good call. i rushed through that post because I was at work and missed that info. Secondly, I spoke to the Trane guy and he was not comfortable handing out his load calcs for fear of shopping it around. I did mention about the 4-ton Amana and his comment was that his calculations originally were at a 2 ton unit before adding the ERV which bumped his calcs up to a 2-1/2 ton. I also discussed my nervousness of the 2-way zoning and he said he has the same system in his house and also mentioned they use a static by-pass damper system. tiger - he did confirm that his was including the 60k btu furnace. Thermostat is the TCONT800 (XL800) and the ERV was the T-ERVR100A9P00A.

Doing some quick research, I see you can get a "T" or an "A" model ERV. What is the difference?

"A" and "T" just indicate the brand name. T for Trane, A for American Standard. Hard to comment on the huge size discrepancy between the calcs not having been to your house, but as already said the Trane quote sounds closer to what I would guess for a well insulated house of that size.

The Amana dealer is quoting the AMVC950905DX furnace which has a 92K BTU input. At a 95% rated efficiency the output would be about 87K BTU.

Why would he recommend this furnace if the heat load calculation is 112K BTU? I guess he doesn't believe the load calculation numbers either.

Do you give both contractors the house plans so that could get the room and window sizes, or did thy just estimate what they would be? Do they know the orientation of the house? Did you tell them the insulation values of the walls and attic?

mike - everyone had the plans. I did the drawings and detailed them well IMO. The second page is the spec sheet with all the insulation properties and the window schedule shows size and window make/model and a total SF of glass. Nobody had any of those questions when I spoke with them and so I am not sure either why the calculations are high. I am still waiting on Carrier to get back to me so I am curious to see how his redesign plays out.

You can get a one time use copy of HVAC Calc for $49. Since you have all the data and know it well, I suggest you do your own calculation.

It would be a shame if you spend all this money on upgrading the insulation and then install an incorrectly sized HVAC system.

This post was edited by mike_home on Wed, Oct 15, 14 at 17:27

I lived in PGH for three years and it is a humid area so variable speed is good for humidity control. I highly suggest that you leave the humidifier out and make provision for adding later. With a well-sealed house, you probably won't need one.

The heating BTU load may be because your using 72* indoors with 0* outdoors. My guess would be if you used a more reasonable 68* indoors with 25* outdoors, the numbers would change downward.

The design temperature for Pittsburgh is 7 degrees F. I would not recommend using 25 degrees as an outdoor design temperature.

The indoor winter design temperature is usually 72 degrees. But if the OP knows he will never go up to that temperature then it would be reasonable to use something lower.

ionized - thanks for the comment and I will definitely look into adding a humidifier later on vs at the beginning. I moved from a house in the North Hills that was your typical 1950's Pittsburgh Cape Cod and in the winter we had a big problem with static which I would like to dry to avoid in my new home. I realize I might be off the mark for my reason on humidity control but in general, I just want to do this system right because I have that option.

to all - can anybody give me a range that I should be paying for a new high efficiency system (as spec'd above) from either Trane, Carrier, Amana/Goodman, or York for my size house? Quotes as mentioned before are on top of each other so thats what makes me comfortable with them but it would be nice to hear from someone on here as a sounding board. Thanks to all the previous comments and suggestions.

2 systems or 1 system with zoning controls?

IMO

one system with zoning controls

What zoning system? how does that integrate with variable speed - sometimes they are exclusive.

If this was my new home, I would get a Carrier or Bryant dealer involved.

These brands have the best integrated system in the residential marketplace for zoning off one system. Infinity HVAC, Infinity controller, Infinity zoning controls.

Regardless though, you must qualify dealer's demonstrated experience in zoning and correct ductwork design.

IMO

You can do zoning with variable speed in 2 ways:

1. Use the manufacturers communicating zoning product. Carrier and Trane are the best examples. Generally, these don't use bypass dampers at all and they have direct control over the variable speed blower.

2. Use any zone panel, but be sure to avoid barometric bypass dampers.

Zoning works best when used with multistage equipment. When you use multistage equipment, zone panel selection is very important. You do NOT want a panel that will stage based on a timer. You DO want a panel that will stage based on the zones calling.