New House

[VictorLawrence]

I tend to get wordy so I apologize in advance. I'll start with come back story, questions will be at the end if you want to skip

My wife and I are from South Carolina and just moved to Central NY so she can attend Cornell's veterinary program. We have both lived in old crappy houses our entire lives, with the last ~12 years being together in a 1994 mobile home (zero air tightness). Luckily, it rarely dips below freezing and we haven't seen snow in about a decade. While our budget is such that we are not going to be building our dream home, we've come up with what I think is a pretty decent compromise: We are building a 40x104 barndominum. The structure will be sheathed, with four inches closed cell spray foam on the roof deck, three inches on the walls, and R14 foam board under the slab (it is a non-weight bearing slab on grade house). There will also be 3" of foam board around the perimeter. The windows are Andersen 100 casements with low-e + heatlock glass. I had never run a Man J before but I downloaded the trial version of LoopCAD and came up with 45k btu heat loss. As a second opinion, I emailed Arctic Heat Pumps my info and they came back 42k btu heatloss, so safe to say I'll be somewhere in the neighborhood.

Though this is not our dream house, I am wanting to put in a few nice-to-haves, such as radiant heat. For months I've been researching air-to-water heat pumps from brands including Mitsubishi, Daikin, Nordic, Arctic Heat Pumps, Enertech, Taco, SpacePak and more. Most of the units are difficult or impossible to get in this country, and digging into the specs most top out at around 35k btu. SpacePak is one of the exceptions with units that go above 60k btu, though at -4F it drops to right around 42k. Where I'm at the average lo temp by month is Jan with an average low of 16F so I think the SpacePak would be ok.

However, this past week I've been putting together all of the components and holy cow are there a lot of additional options. To back up a smidge, I found a PE of fourty years that was going to design my system when I met him last year, but then when I came to him with radiant and air-to-water heat pumps he got confused because...HE HAD NEVER EVEN HEARD OF THAT TECHNOLOGY! He then tried to sell me on putting mini splits in every single room (6-8 would be needed) so I quickly dropped him. Back to present, I have found another person/company (heatloadusa.com) that I am about to pay to run a full Man J/S/D. However, I still need to tell her (them?) what some of the equipment will be, normal duct vs high velocity, etc

This is where I need help. I was mostly settled on getting the SpacePak ILAHP, but I'm not sure if it would be better to get their SIS unit so I don't need a 45% glycol mix (but the SIS is $3000 more expensive), not sure if I can hook up a regular air handler to that to avoid how expensive high velocity runs are (I'm assuming I could?). Would I need a backup electric boiler as a backup? considering the price of a boiler vs ILAJHP/SIS, would it be better to just skip a heat pump altogether and just run an electric boiler. If I do go with SpacePak, they can also cool which means I'll have duct work, so would it be beneficial to through in their $1000 electric heater to the air handler?

Another thing, HeatLoadUSA doesn't do makeup air calcs, but I'm assuming I would just match the Fantech CFMs to that of my range hood? (750cfm in both cases).

Main goal is to be all electric and energy efficient as possible within reason (eg can't afford geothermal). Today I was also reading a post on Green Building Advisor about how it can take awhile for in-slab radiant to catch up if the outdoor temp had a big fast swing when the sun goes down.

I thought I was so prepared now my shell is going up in a few weeks and I have no clue how I'm going to heat it this winter. Any advice is greatly appreciated.

[ModestoGarr]

Hi, Is it too late to increase the insulation in the walls and roof? Those measures would make heating the place easier and cheaper. Just to expose my slant, my walls are 8" foam and the roof is 12". Heating is very simple.

[kevinabraham]

When it comes to heating options, it's definitely a jungle out there with so many choices. It's smart to weigh the pros and cons of each, especially since you're aiming for energy efficiency.As for the radiant heat vs. air-to-water heat pumps debate, it sounds like you're doing your homework, which is half the battle. Don't stress too much about the options overload – sometimes, going with your gut instinct can be the way to go.By the way, I recently stumbled upon this dubai real estate companies and started pondering a move to the UAE. Crazy, right? If you're exploring new horizons like me, maybe check out sandytimes.ae for some inspo.

[steviewonder]

The SpacePak ILAHP and SIS units seem like viable options, with the main difference being the glycol mix requirement. If you can accommodate the glycol mix, the ILAHP may be the more cost-effective choice. However, if you prefer to avoid the glycol mix, the SIS unit could be the better option, even with the higher upfront cost.
Regarding connecting a regular air handler to the SpacePak unit, this is generally possible, but you'll want to confirm compatibility and ensure the air handler can handle the system's output.
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