New build; what route to take?

drewster2016

Hey everyone. First post. 

Looking at doing a 16-1700sqft Modular ranch here in ma. Currently just in the planning stages but hoping to start pulling the trigger soon. Trying to figure out the best route to take for the mechanicals. Here are the options I have come up with so far. Any advice is appreciated! House is going to be forced air with registers in the floor (possibly in the ceiling but not 100% sure yet)

1: heat pump with propane furnace backup, propane tankless water heater

2. Heat pump with propane furnace backup, heat pump water heater 

3. heat pump with oil boiler backup, hot water off boiler  

Don’t plan on having any other propane appliances, would probably rent a 120gal tank as I don’t imagine I’d go through tons of propane, but never had propane so could be wrong. 

Previous house we had oil baseboard heat. (I work for an oil company and can service the boiler myself) obviously pricing will play a big factor.
No plans for solar/geothermal

Curious to see what route people Would take.

Hot_water_fan

I like 1 or 2. I’d skip the tankless unless you’re short on floor space. So tank, either propane or electric heat pump. A new house that size should have a low heat loss, so a heat pump could handle it all, but the propane is easy power outage insurance, even if propane operating costs are high. A propane furnace is a better sized backup than oil. 

drewster2016

Hot_water_fan said:

I like 1 or 2. I’d skip the tankless unless you’re short on floor space. So tank, either propane or electric heat pump. A new house that size should have a low heat loss, so a heat pump could handle it all, but the propane is easy power outage insurance, even if propane operating costs are high. A propane furnace is a better sized backup than oil. 

I was leaning towards 1/2. Only reason to consider oil is that I work with it and have the knowledge to work on the boiler myself. And from what I hear oil is a bit cheaper than propane currently (but that fluctuates) I’m not sure how well the new home is going to be insulated but I’m assuming it’ll be fairly decent. I’m sure I could get away with just the heat pump. But I talked to some of the techs at work and they suggested having a backup. As the electric strips are EXPENSIVE to run and our electricity is already super expensive. 

Plenty of floorspace in the basement. I hear a lot of people like the tankless propane heaters  but again I don’t have experience with them or the heat pump water heaters. Not sure about tanked propane heaters. Don’t they cycle often to keep the water warm?

ChrisJ

#4 : Heatpump with propane furnace and a propane tank WH.

But #5 is by far the best.
#5 propane boiler and propane tank water heater. Separate air handler ductwork for heatpump and AC.

drewster2016

ChrisJ said:

#4 : Heatpump with propane furnace and a propane tank WH. But #5 is by far the best. #5 propane boiler and propane tank water heater. Separate air handler ductwork for heatpump and AC.

May I ask why a propane tank water heater over a tankless? 

#5 what do you mean separate ductwork? From my understanding (I am just researching so I am very clueless currently) is the best pump does the cooling and the heating? Why would I want a separate boiler and ductwork? 

ChrisJ

drewster2016 said:

ChrisJ said:

#4 : Heatpump with propane furnace and a propane tank WH.

But #5 is by far the best.
#5 propane boiler and propane tank water heater. Separate air handler ductwork for heatpump and AC.

May I ask why a propane tank water heater over a tankless? 

#5 what do you mean separate ductwork? From my understanding (I am just researching so I am very clueless currently) is the best pump does the cooling and the heating? Why would I want a separate boiler and ductwork? 

I meant a propane boiler with either in floor radiant, baseboard or cast iron radiators and then a separate system with ductwork for the heatpump A/C.


I don't care for tankless. They seem to have too many issues for me so I've stuck to a power vented tank so far. I just replaced mine last summer.

Hot_water_fan

I hear a lot of people like the tankless propane heaters but again I don’t have experience with them or the heat pump water heaters. Not sure about tanked propane heaters. Don’t they cycle often to keep the water warm?

The tankless are great at saving space. They're equal in terms of efficiency and capacity to higher capacity tank units. In my opinion, there's not a compelling reason to make hot water instantaneously, it's cheap to store. Having a buffer lets you have short, high draws of water without going cold like a tankless would.

s the electric strips are EXPENSIVE to run and our electricity is already super expensive.

They are, but remember that's only a small portion of the year and the house isn't sprawling. Electric strips, cold climate heat pumps w/o them, and propane backup all have pros and cons. Strips are cheapest and let you size cooling better, propane provides backup in case of power outage (provided you have a generator) and cold climate heat pump is a bit cheaper to run and avoids the propane tank expenses.

Zman

What are your DHW needs? Big tubs to fill or low-flow fixtures? Do you need AC? What are your local propane and electric prices?

drewster2016

Zman said:

What are your DHW needs? Big tubs to fill or low-flow fixtures? Do you need AC? What are your local propane and electric prices?

Only 2 of us, right now, so no big tubs to fill or anything like that. Don’t *need* AC but figure it’s not going to cost much more to add, may as well do it. 

I have no idea what propane costs I’d have to call around 
electric is about .24 cents I think ( would have to confirm as well) but you can lock in a lower rate (.17) obviously subject to change 

hot_rod

Planning on being there for years? Decades?
Build the house efficiently as possible. Imagine 10- 15 BTU/ sq ft design load.
1700 X 15= 25,5000 btu/hr load. Or less! Some passive solar possible?

This makes a 3 ton ccA2WHP a viable option. AC? Some units can also provide DHW if you don't mind all your eggs in one basket. You'll need some space for a buffer tank, even with the variable speed HPs.

What type of heat emitters.

Radiant floors, walls or ceilings would be the lowest SWT. panel rads next

Cooking, clothes drying? Electric or LP?

Budget?

Certainly if you can service oil, you can service basic LP boiler. With a 25K load and low temperature emitters a LP water heater could be the backup, no need for a boiler.

#2 If 2 gpm DHW is adequate a 120 combi would cover heat and dhw. Mini split for AC.

No question a properly sized/ applied HP will have the lowest operating cost, shoot for 2.5- 3 COP in your design. SWT below 120F is the key.

The HP examples in this journal are upstate NY area.