Lots Of HVAC Questions For 1200 SF New Construction

Badfish740

I am in the process of evaluating my potential costs for building a "Katrina Cottage" from Lowes. Though the materials come as a package, no HVAC equipment is included, which I'm assuming is because there are so many options.

Am I correct in assuming that forced air heat will end up being the cheapest to install simply because the air ducts will be shared with the AC unit, as opposed to having to run pipe for a boiler AND ductwork for the AC? If so, I will definitely go with forced air, so lets assume I will.

The home in question is 1200 SF, 3 bedrooms (one on the first floor, two on the second), 2 bathrooms (one up one down), 8 rooms total (counting both bathrooms and the kitchen), 9 foot ceilings on the first floor, and 8 foot ceilings on the second floor. The home will sit on a full height heated basement, and will have 2x6 outer walls with R-19 insulation. The 2nd floor ceiling will have R-30 insulation. There will be a vented attic above the second floor. The two upstairs bedrooms will share one wall and will have two outer walls each. The downstairs bedroom will have three outer walls.

Based on that criteria, can anyone give me a ballpark size on a gas forced air heating unit and an AC unit? The home will be located in New Jersey, and as a side note I will also be installing a woodstove in the living room at the time of construction and intend to make use of it throughout the fall/winter.

Finally, (I realize this is a REALLY ballpark figure) what could I expect to pay to have the HVAC units and all ductwork installed? I'm just trying to get a rough idea so that I know what I'm looking at during the bidding process.

Thanks!

coolmen

what part of jersey ? You need to get a load calculation done to know what size is needed to get the best effiant system for the house.. to big is bad as well as to small. 1200 sq new construction good insulation, how many windows ? A guess would be 50,000 x 24,000 however a load calculation will put you pretty much where you need to be with equipment select.

MechanicalDVR

Ballpark would be 60,000btu furnace with 2 tons of a/c, depending on the glass type/amount/exposure.

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Badfish740

Thanks guys-I know I need to do a real load calc before I buy anything, but I just wanted to know what range of equipment I'm looking at. At least I know that I can price units in the 60,000 BTU/2 Ton range. What do you think of the HVAC-Calc software? I saw on their website that it was available as a trial version or something to homeowners for $49.99. Any good? By the way-the design calls for 14 windows, two outer doors, and I'm looking at the Warren County area, which is usually a few degrees colder than other areas of the state, but nothing dramatic. You're usually talking a difference of 200-300' of elevation. "Mountain" is a relative term here

coolmen

The hvac calc software is used by me on every one of my jobs. I find it to be fairly easy to use. being a first time user double check all the input info. I personally will add 20 % margin of error on the heat loss side and pay attention to the cooling sensible BTU and select equipment that will handle coolind sensible. I do work in warren county if down the road your in need of help.
Good luck,
CJ Mechanical of north jersey

Badfish740

Coolmen-thanks for the heads up. I'm looking at a few different building lots in the area with the help of an excavator who does septic systems, so we'll see what I come up with. Anyway, I just thought of another question. I plan on putting a woodstove in the living room on the first floor. Some of the Vermont Castings stoves put out quite a bit of heat, which would certainly help with the gas/propane bill, but I'm curious about something. I know that an oversized heating system is bad since because it won't run that often you can have problems with moisture and not enough air changes. If I'm burning a lot of wood during the winter, could it be ultimately detrimental since my furnace isn't running as much as it normally would?