I am currently building a new house and the framers are almost done so we are about ready to start rough ins. My house is going to have two electric heat pumps. One for downstairs and one for upstairs. I am not ready to install a boiler yet, but I want to do any rough ins now so it will be easier to install later. I plan to have the boiler run my hot water and put a heat exchangers in my heat pump duct work for house heating. I already had a sleeve installed in the foundation so it will be easy to install the waterlines from the boiler into my crawl space. What else do I need to have done now as far as wiring and piping is concerned? I am mainly concerned about anything that would be in the wall behind drywall making it difficult to access later. I am thinking i need to run a supply and return water lines from the crawl space to the attic since the duct work for the upstairs will be in the attic. Is standard Pex ok for this? If so what size should it be? Does it need to be insulated in the wall/pipe chase? Any electrical wiring for thermostats or controls need to be run? I am just trying to do everything now so I am not ripping out drywall later. Any info or help would be appreciated.
Prepping new house to add outdoor wood boiler later
- Thread starter fourwheelinj1
- Start date
-
Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.
We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.
We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
maple1
Minister of Fire
Bad LP
Minister of Fire
NEVER NEVER AGAIN. Built a 3500 sqft spec house a few years ago. NG unit in the attic for the second floor. House was all spray foam including the roof so the unit was in the conditioned space. I swore that if I ever built another house the equipment would not go in the attic. PITA to service and all that ductwork makes the attic useless for anything else.
When starting from scratch there is no excuse not to run ducts up within closet walls.
Manage another property where there are 5 hydroair units in the attic. Its a big place but working on these units is always tough. I'd like to stab the architect.
When starting from scratch there is no excuse not to run ducts up within closet walls.
Manage another property where there are 5 hydroair units in the attic. Its a big place but working on these units is always tough. I'd like to stab the architect.
maple1
Minister of Fire
Also mention of foundation & crawlspace & sleeve in between is a bit confusing. Are you talking an outdoor boiler? The horse might be too far out of the barn for the overall optimization you're looking for.
I'd run supply and return Pex (if the system is treated it can be standard Pex) from top to bottom air handler and to the water heater area, along with at least a 3 wire thermostat wire to signal a pump. That run could be uninsulated as it should only have to run during a call for heat.
Then run insulated piping (1" Pex minimum) from the water heater to the sleeve through the wall and 120 v. power wire from panel.
Run extra thermostat wires from wherever you want the stats to the air handlers.
So with all this you can pump a continuous primary loop to a flat plate at the water heater, secondary loop off that through the coils in the ducts during either stat's call for heat.
Then run insulated piping (1" Pex minimum) from the water heater to the sleeve through the wall and 120 v. power wire from panel.
Run extra thermostat wires from wherever you want the stats to the air handlers.
So with all this you can pump a continuous primary loop to a flat plate at the water heater, secondary loop off that through the coils in the ducts during either stat's call for heat.
Yes the duct work is in the attic. That is how pretty much all homes are built here in NC. My attic is a huge walk in attic though so there is plenty of room to work. And yes i am talking about an outdoor wood boiler. So i need to run a pex supply and return line from the crawl space to the attic but what size? The upstairs area being heated isn't that big. Its only about 800 sqft. So I need to run extra thermostat wire from the thermostat on the wall to the air handler both upstairs and down, but what about the controls for the pump? Does a thermostat wire run that also? If so i guess i just need a thermostat wire from the crawl space to the thermostat location upstairs. Is that right?
Yes, I see that kind of setup in VA too a lot.
We usually run 3/4" Pex from top to bottom as it will push air out easier and still has enough flow to heat fine.
If you pull an extra stat wire from the upstairs stat location to the upstairs air handler, and also from the attic to the crawl space you can splice whatever you need later to signal the pump relay. Basically we pump a loop through both coils and relay it so either thermostat can turn the pump on to pump the loop.
And if your top and bottom air handlers are in accessible places like an open attic and crawl space all you really need is the two Pex pipes from top to bottom with a stat wire. And extra stat wire to each stat location, and wire down into the crawl space from the panel.
We usually run 3/4" Pex from top to bottom as it will push air out easier and still has enough flow to heat fine.
If you pull an extra stat wire from the upstairs stat location to the upstairs air handler, and also from the attic to the crawl space you can splice whatever you need later to signal the pump relay. Basically we pump a loop through both coils and relay it so either thermostat can turn the pump on to pump the loop.
And if your top and bottom air handlers are in accessible places like an open attic and crawl space all you really need is the two Pex pipes from top to bottom with a stat wire. And extra stat wire to each stat location, and wire down into the crawl space from the panel.
Last edited:
Similar threads
