r/PassiveHouse

We live near a nuclear power station and a big city and I am the type of person who just likes to know where the airplane exits are, so that they’re in the back of my head just in case….

What do I do with my MHVR if nuclear dust was to be settling around the house? I am not sure how many days sealing off the MHVR would be safe for in the house before oxygen is a problem.

Building cold storage in the UAE isn't just about cranking up the AC—it’s an ongoing battle against extreme external heat and internal humidity control. When we engineered our latest mobile container cold rooms, we had to rethink a few standard industry practices to keep power consumption low and food/pharma shelf-life high.

Here are the 3 biggest technical hurdles we solved:

• The Thermal Bridge Problem: Standard shipping container steel frames turn into ovens under the desert sun. We had to implement a complete thermal break using high-density polyurethane insulation panels (100mm to 150mm thickness) to ensure zero metal-to-metal contact from the outside to the inside.
• Precision Humidity Control: In cold storage, moisture is the enemy—it causes evaporator icing and ruins agricultural produce. We integrated active dehumidification cycles that balance the relative humidity ($RH$) perfectly based on what's inside (e.g., maintaining 85-90% $RH$ for fresh vegetables vs. low humidity for dry logistics).
• True Plug-and-Play Mobility: The goal was a unit that could be dropped off a flatbed truck on a remote farm or construction site and running within an hour. We localized the entire refrigeration plant onto a heavy-duty, integrated skid with smart monitoring so it operates autonomously.

If you are dealing with cold chain logistics, vertical farming, or specialized commercial cold rooms in high-ambient temperature regions, I’d love to chat about what specs you're running.

Drop any questions about insulation, cooling loads, or humidity control below—happy to talk shop!

Hi folks,

Wondering if there are any good rule of thumbs to follow when looking at buying a home on its potential to retrofit/ how much things can be improved before a reconstruction makes more sense?

New construction costs are such that we are priced out of that. Instead we are looking at lot sizes / older well built homes that allow us to renovate overtime.

Here is an example:

https://www.zillow.com/homedetails/3767-N-Raleigh-St-Denver-CO-80212/13312228_zpid/?utm_campaign=zillowwebmessage&utm_medium=referral&utm_source=txtshare

Of course I could consult with professionals in this space, but I'm more interested in sense checking when searching for properties before knowing when to move on and continue search versus spend money for inspections etc and invest time in pursuing.

Thanks all!

Looking for opinions on whether I should install triple pane,Saint Gobain Cool lite glazing or double pane in the Philadelphia Suburbs.

We are considering,,AdamS or Oknoplast, uPVC windows. The triple upgrade is very reasonable. The salesman feel the triple is unnecessary in this area.

Much less expensive than Marvin.

Any opinions?

Thank you

I am adding an extension to my house and late to the game on efficiency and so now backing into an energy strategy.

I am trying to figure out how we can create the air barrier for an unvented attic and use exterior insulation to the roof, which gives us a better approach across the old and new roofs.

The design for the new roof includes trusses with 6 inch tails / cantilevers. I am trying to figure out how we can create an air barrier for the conditioned attic and also support exterior insulation on the roof.

Because we're backing into this the trusses have been ordered and are currently in production. I can't make changes without some significant costs.

Unfortunately my architect is not knowledgeable about building for energy efficiency and isn't helpful. My builder is old school but willing to learn and build whatever we ask for. We've just run into an issue and I don't have anyone on the project that can help work through our overall approach to the thermal and air barriers, insulation and building constraints.

I'm hoping this community has seen this before, and any approaches or links to sources would be much appreciated.

The old roof has rafters that I think we have an approach for, but I'll take any advice here as well.

Thanks

The consumables of our passive house bugged me during the design phase. I purchased a case of filters for our European ERV system 10 yrs ago and in that time their price has gone up just like everything else. Originally I hoped the market would democratize, others would be producing similar products and through competition the price would fall. That hasn't happened.

I know little about filter materials but imagine cutting out the spent stuff and glueing into the proprietary shaped plastic frame filter membrane I've taken from a similarly rated material could work... if done right. The glue, material, there are concerns that the rabbit hole that is research will make it worth it.

Any suggestions? I'll post similar to the HRV reddit too.

Ive seen a lot of controversy, regarding insulated houses and their ability to keep you cool in summer as well as warm in winter. well here is definitive proof. Thanks to Guy Martin.