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4 Answers

Ductless minisplit question

What models are available that will work at the lowest temperatures, it would be for a house in zone 4 (close to 5), about 4500HDD, at a design temp of -5F (-22C). The owner would likely keep the house temp at about 15C all winter, and the house probably has a heating load in the 20-30k range (at room temp so less at 15C).

Cost is of course a consideration, its an open concept two floor house with cathedral ceiling and unfinished basement,

Asked By Alan B | Apr 20 15
21 Answers

Is it reasonable to use 3/8" PEX supply lines to all fixtures?

I am planning the plumbing system for my Net-Zero Energy home that is being built to Passive House standards. I will be using PEX tubing with a manifold system using home runs. I designed the house so that the bathrooms and laundry room are centrally located, making the supply runs pretty short. I want to minimize the amount of water and energy being used and low-flow fixtures provide plenty of water for my needs (2.2 gpm at sinks and 2.5 gpm for showers).

Asked By Gerald Blycker | Mar 11 14
1 Answer

Thermal bridging via a steel I-beam in an exterior wall

We have a masonry row house building with interior insulation (about R16) in New York city. The exterior of the building consists of 3 wythes of brick (about 12" thick). We are now building a steel frame deck. 2 steel i-beams will be inserted into the outermost wythe to support the deck. Does this present any kind of thermal bridging?

Note, the i-beam does not penetration the two innermost layers of brick npenetor the interior insulation. It only penetrates 4 " or one brick width in.

Asked By Daniel Herskowitz | Apr 21 15
15 Answers

'Finishing' above-grade Roxul Comfortboard: What are the best practices?

I'm building a new home. The exterior of the home, from the bottom of the basement to the edge of the roofline, is covered in 2" Roxul Comfortboard.

Asked By Ryan Lazuka | Apr 14 15
8 Answers

Vented SIP roof — fascia detail

Trying to find a photo or a detail of a vented SIP roof fascia area. Typically they use 1x or 2x furring strips on top of the SIP and then the layer of sheathing and roofing material. How the fascia gets finished is something that is hard to find. There is a 1" or 2" vent gap there so how does that all come together?

I did an internet search and could not locate any such detail.

Asked By Peter | Apr 16 15
2 Answers

Insulation under lap siding on the west side of a house

I am changing out the siding on a 1987 house that has a tyvek layer. With window trims I do not have space for a think insulation thus can only use a 1/8-1/4 inch thickness This is at 5600 feet on the west side where there is a lot of afternoon solar gain. Is there a thin insulation (possibly with a reflective coating) that I can put between the Tyvek and the siding that will help block summer heat. It would also be great to help keep in winter heat. House is located in Colorado any comments are appreciated.

Asked By Mark Rosenblum | Apr 21 15
25 Answers

HPWH, HRV, bathroom vent, stove-top vent, make-up air, and balancing house ventilation

So ventilation or rather balanced ventilation seems so distant, especially when using a comprehensive ventilation strategy for all the appliances that need ventilation.

The house will be built in zone 6A, and is all electric, with PV - hoping for Net Zero.

Asked By brad hardie | Apr 9 15
1 Answer

Is it a good idea to condition a crawl space instead of insulating it?

what would be better for a crawl space/sleepers to insulate or to do a parameter insulation and condition the area with the house system
thanks in advance

Asked By Schlomo | Apr 20 15
18 Answers

Building my own home in North Dakota

Hello, I've been lurking on this website for a few months and have found the information to be invaluable. I live in central North Dakota (technically Zone 7 and about ~9500 HDD) and am currently building my own house. My family and I plan on living here for many decades, so I'm very focused on building an efficient and comfortable home. I am also trying to keep a reasonable budget and simple design. The house will be split entry (lower level is half underground and half above ground) with approximately 1200sq ft. per level. The foundation has already been poured using ICFs.

Asked By Adam Emter | Apr 19 15
5 Answers

Laying out mini-splits for a new home

I have a new home in the design stage and have been working with with my HVAC sub and the wholesaler to layout and locate mini-splits for the project. The house will be 2550 sq.ft. on a slab with R40 walls, R75 ceiling and very tight. We are in zone 5, floor plan is attached. We will be installing an ERV for fresh air.

The HVAC guy and the wholesaler want to put a head in each bedroom as well as the entry, office, family room and great room and run them off of 2 separate outdoor units. Their concern is to provide uniform temps throughout the house.

Asked By Terry | Apr 17 15
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