HVAC for Climate zone 6, NY State
I am preparing to build our home this upcoming year. I thought I had my mind make up on what to do for HVAC but now I’m not so sure. I am self performing a lot of labor.
-2,700 square foot home. Two story. Living room is about 18 x 18, open to two stories.
-2×6 wall filled with batts, 2” rigid exterior foam. Huber Zip wrb.
-I have plenty of windows, Marvin elevate.
-shooting for under 1ach50.
– natural gas is available
I was planning to do hydronic radiant throughout, using the ultra fin system. A/c will be ducted forced air, zoned into 3, with a dual or variable speed unit. We are not a fan of forced air heat. One concern I have is that I am already being inefficient in using two different systems for heating/cooling. Now, radiant will be fairly inexpensive for me as I can run all the pipe, install the fins, etc. However, will it be effective in a tight and well insulated home.
I am not a huge fan of the ductless mini splits. National Grid (our utility company) has some incentives right now for heat pump systems. My budget is limited, I’m not building a super expensive home, but I would like to install a decent hvac system, balanced with efficiency and cost. Can someone give me some ideas based on their experience?
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Replies
Hi Dennis,
A ducted, variable speed heat pump allows you to use the same ducts as AC and will better match your homes heating needs than a furnace can. It can easily be supplemented with gas or electric as well.
Another, less common, option would be an air to water heat pump, which would thrive with the low water temperatures a ultra fin system would require. The low temps (based on your building’s anticipated insulation and air sealing) also mean the floor will not be particularly warm.
Even DIY (loops not the boiler itself), the hydronic portion (boiler or air to water heat pump) will not be cheap, so the extra $10-20k or whatever is your call.
Thanks for the reply Paul. If you don’t mind explaining, why would a ducted heat pump suit my needs better than a gas furnace?
Modulation - a ducted heat pump can lower its output much lower than any furnace can. For example, a Mitsubishi 3 ton Hyper heat can go down to 13k Btu at 47 degrees. The highest end Trane furnace can only get down to 24k Btu, so will cycle 2x as much with cold air being blown in between cycles.
A ducted heat pump is also much more efficient. The most efficient furnace can only get .99 MMBtu output for every 1 MMBtu gas input. A heat pump can get 1.5+ MMBtu for every 1 MMBtu gas input.
They can be paired - a heat pump handles the majority of the heating with a furnace coming on for the coldest temperatures when cycles are longer and a heat pump loses some efficiency.