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8 Answers

Boiler upgrade recommendation?

I’m currently looking to upgrade my old boiler as it developed a small crack and is leaking. My current boiler is a P-468U-wt (151,000 btu/hr) Weil-McClain oil-fired boiler with a 40-gallon hot water holding tank.

I’m getting two different suggestions from two of my plumbers and would love some input on their recommendations. One recommends replacing it with an Energy Kinetics System 2000 and the other one is suggesting a Navien Combi-boiler.

Asked By Joe Pavia | Jul 1 15
22 Answers

It's 2015 and they still build like this...

Brand new build going up in Phoenix, AZ. What you see is completely 100% framed and ready for stucco. The missing OSB sheathing is done on purpose. They do "open framing" and only use sheathing where required. The rest is open 2x4 framing.

They will stuff R-13 batts within the 2x4 walls, staple on some building paper and then put 1" of rigid EPS on the outside and use conventional stucco to finish it off.

A recent blower door test on a home like this showed 15 air changes per hour.

ALL of the duct work and air handlers are installed in the 150F unconditioned attic.

Asked By Peter L | Jul 1 15
10 Answers

Is my 5000 BTU LG 10 year old window unit significantly inefficient ?

My wife says so, in comparison with similar modern window units. She wants it replaced. The unit runs on all work days, during summer work hours, in my home office in San Antonio, Texas. San Antonio summers are hot, but not as hot as north Texas, as an example comparison. My question is whether efficiency advances in 10 years have made a big difference for small window units.

I tried to search, but every search returned hundreds of irrelevant topics.

Asked By Weldon Cabaniss | Jun 28 15
65 Answers

Attic is hot after closed-cell spray foam was installed

Finished attic with 4 foot knee wall , duct located in knee wall to support 2 floor,extremely hot, BASF spray tite 2 inches with spray foam wraped around rafter in knee wall but with Sheetrock on ceiling just 2 in foam In cavity . Suggestions to handle heat issue. Richmond Virginia all attic seal very well thinking heat coming from rafters under Sheetrock. Thermal convection coming from rafters. Worked done in the winter, crawl space also done, house built 1994 colonial 2 story with garage with room above with dormer. Also in crawl space does it really need supply vent and return vent

Asked By Mark Hippchen | Jun 27 15
7 Answers

ZIP R-Sheathing Climate Zone 5?

I am considering ZIP R-sheathing for a home in Climate Zone 5. The wall assembly would be a ventilated rainscreen as follows (exterior to interior)

1. Hardie Panel siding
2. 3/4" furring/airspace
3. ZIP 1.5" R-sheathing (R6.6 total, 12-16 perms for the OSB, <1.0 perm for the polyiso)
4. 2x6 studs
5. Icynene Low Density (5.5" thick R-20, 11 perms)
6. 1/2" gypsum

Asked By Joseph Yount | May 12 15
5 Answers

Relative value of air sealing at exterior sheathing

I am trying to understand the relative value of air sealing at the sheathing. To do this lets consider cost as the benchmark. I realize that there is value beyond cost but this is an easily quantifiable benchmark and the one that seems most resonate with my clients.

Asked By Hugh Stearns | Jul 1 15
74 Answers

Geothermal nightmare

We truly hope you can help us. We had a geo-thermal closed loop system (into the river) put in and it went online March 2012. WaterFurnace Super DeHeater, 4 Multi-Aqua mini-splits (included for AC) and an air-handler (included for AC). 3200 sq ft home with baseboard and in-floor radiant heating. $34,000 and we have had nothing but problems.

Asked By Colleen Nicholson | May 30 13
3 Answers

Details about drywall under tongue and groove as an air barrier

I have read often on gba about the importance of using an air barrier under tongue and groove and I may be over thinking it but it seems that 1/2" ultralight has the potential for more air leaks around nail penetrations due to occasional voids in ultralight and that 1/2" could more likely bust around nail penetrations and let air in versus 5/8" but before I wear myself out hanging 77 lb sheets I figured I should ask an expert.

Thanks,

Matt

Asked By Matthew Seabolt | Jul 1 15
5 Answers

How do I get and keep air out of my geothermal loop?

We have a "closed loop" geothermal heating and cooling system. 97 wells 300 ft. deep. 4 story building. 36 water source heat pumps. 72 electric water pumps. 219 ball valves.
There is no way at the high point (attic over 4 story) to release air and no easy way to add water to displace the air. The contractor keeps trying with their big pump and tank trailers to purge the system by driving the air bubbles out through the basement. No surprise to me, having observed the bubbles in my bathtub travelling upward, this approach keeps failing.

Asked By Todd Conradson | Jul 1 15
1 Answer

Dense-packed cellulose in exterior walls

I have a 100+ year old home and there is currently no insulation in the walls. There is vinyl siding on the exterior and I think it was installed over the old wood siding. I am considering having dense-packed cellulose blown into my 2x4 exterior walls. Am I going to have a moisture problem if I do so? I've read conflicting opinions. I would appreciate any advice you can offer.

Asked By T S | Jul 2 15
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