My first thought is that builders hate change orders and usualy increase cost to buyer disperportionaly to what it increases the builder's cost. My next thought is that it sounds like a large footprint and you are useing one unit with 3 stats to zone. Make certain the HVAC contractor is compident in that type system because it is almost a specialty of it's own. If all or at least most zones are in use most of the time,a zoned single unit is ok. If one or more zones are vacant much of the time,multiple units are a better choice. And finally,don't overlook mini-splits,they are coming on like gang busters in North America.

thanks,
tell me about mini-splits...what should I ask the builder about? We are still in preliminary design phase so no change orders yet :)

We anticipate the two largest zones (first floor and lower level) to be used all the time, with the small bonus space on the upper level being a guest space that will be used much less.

The HVAC contractor is the same as the builder....this family has a HVAC business and a building business. The sales guy in the building part of the business told me a story of how once thie.r own HVAC company lost a bid on a house because of random quality control they have in place to check that they are staying competitive. The random quality control they have in place is for all contractor types not just the HVAC.

Anyways, what I'm trying to say is that although I don't know how to assess their competency I do know they do this type of installation routinely (18-20 homes per year).

Are there any questions I should ask about how they handle the HVAC? What do you think about the equipment? I got ahold of another home's specs from this builder in the same geographical area and they have a 100K btu unit where I see ours is 80K.

Also I see that our a/c is only 13 seer which is federal minimum. Is that a problem? We probably only us a/c for about 3 months out of the year and then on rare record high days in another month or two. but usually summer in Michigan is truly 3 months out of the year.

It sounds like a local company that has maintained their repitation so you should get what you pay for. Were you in the South,I would reccomend higher seer but with your mild summers,the payback would be much less. 13 seer makes sense for your application. Don't overlook asking your electric supplier about rebates and incentives for energy effecient appliances,lighting,hvac,windows,additional insulation or other upgrades.

Thanks for the suggestion about reebates. My question is will this equipment provide us good comfort? What does going to a 100k unit gain us?

I did forget to mention a whole home humidifier will be installed as well.

I don't believe you need the 100 K size Infinity furnace.

I would upgrade to a higher level SEER and model on the AC condenser.

Infinity controller and box filter cabinet.

If you are planning on 3 zones off one system, I would go to a two stage condenser and definitely Infinity zoning controls.

IMO

One other thought.

From your initial post, you describe the 925T as a var speed model furnace. In fact, it is not var speed. It does have a high eff blower motor but it is not var speed. You should know this.

IMO

Here is a link that might be useful: 925T Bryant Furnace

Google "minisplits", "mini-splits", or "mini splits" for info about those. Gas is so cheap now that it does not make sense to use heat pumps in a predominantly heating environment unless you think the price will blow up.

You might consider waiting on the humidifier being sure that you have the system designed to add one. New, tight homes don't have as much need. When heating, leaking homes and leaking exterior ducts cause low humidity.

thanks for letting me know that is not variable speed. I copied what the builder sent me on my inquiry about standard hvac equipment.

Do I need variable speed? (I don't even know what that means). I will ask about the infinity controller, two stage condenser, etc.

hmmm, one says 13 seer is fine, another says not enough.

This post was edited by illinigirl on Sun, Aug 4, 13 at 18:32

If the best dehumidification in AC cooling mode is important to you, then yes you should go var speed.

If you plan on zoning controls to handle multiple zones off one system, then yes go with two stage condenser as well. Preferably Infinity or Evolution zoning controls. Not cheap but the best in residential market.

IMO

another question- do i need to upgrade the furnace to an Infinity furnace in order to upgrade the thermostat to the Infinity? Or could I upgrade to the Infinity controller without upgrading the furnace?

I'm still waiting back on the costing of the different upgrades. I'll post them when i get them.

oh, they do include a box filter cabinet, which builder says is easy to change out the filter.

"another question- do i need to upgrade the furnace to an Infinity furnace in order to upgrade the thermostat to the Infinity? Or could I upgrade to the Infinity controller without upgrading the furnace?"

Yes. I would.

IMO

alright, for $2500 we can upgrade to these models:

187BNA048000 Bryant Evolution two-stage a/c

987MA6080V21 Bryant Evolution modulating furnace

SYSTXBBECW01 Evolution Connex control w/WI-FI

what do you think?

thanks!

What model evap coil?

What did you decide about the zoning?

Otherwise a top of line system.

Ductwork must be sized for 4 ton cooling. You want adequate returns. R-8 insulation on ductwork minimum.

I really would prefer to see a load calculation in writing both cooling and heating for correct sizing. I would insist on it.

If your new home has good building and insulation qualities, you might could get away with a 3 ton condenser since this is new construction.

IMO

we are definitely doing 3 zones. I don't know the evap coil model.

Based on what the builder is telling me the homes they build are pretty tight. I forgot what the HERS scores he said were typical for their builds.

thanks for the info. I'll ask about a 3 ton condenser. When you said we want adequate returns, is that achieved with your ductwork size recommendation or the number of returns or other?

I'll make sure to get the load calculations.

Does the upgrade figure ($2500) sound reasonable for this system?

thanks!

I actually would prefer to see a load calculation in writing both heating and cooling for accurate sizing. I would insist on it.
If your new home has good building and insulation qualities, you might could get away with a 3 ton condenser since this is new production..

Here is a link that might be useful: Heating and cooling Toronto