Recent content by Mark_F

Thanks again for your expert and knowledgable discussion of this! You clearly possess a lot of detailed and specific knowledge about these products, systems and more. Are you an engineer of some type?

If I do pipe the furnace intake to the outside as planned, so I can close off my crawl space vents, I am concerned about the effect of that on the crawl space. I don't want to create a condensation/mold type issue. This is a very dry climate and the crawl space is very dry. Radon may also be a...

The foundation walls are insulted with rigid foam, but I think it's only like 1.5" or maybe 2" can't remember. R maybe 10. It was a long time ago. I could go look and verify but you get the idea. Crawl space floor is unfortunately dirt and very uneven with lots of big rocks. Wish I had done a...

Wow Dana. Very thorough discussion. When I built the addition in 1986 the code was for R30 in roofs. Now everyone uses spray in foam and I don't know what r-value they achieve but it's high. Also eliminates the need for venting the rafter spaces. Like you , I like to be thorough and if I'm...

Dana, you rock! All the info I wanted to know and more. Very helpful, Thanks! I’m not sure what stack effect is, but I’m going to learn more about it and will seal off the B vent at both open ends in the attic. The attic is a “cold roof” so the attic isn’t actually vented. The vent space is...

No, the furnace gets it’s combustion air from the crawl space. The crawl space is vented as stated above. I show the attic photo so you can see where the combustion air pipe would come up to and turn out thru the wall and exit as shown in outside photo. The pipe is 3” all the way, not sure...

I recently had my older 80% efficient gas furnace replaced with a new 98% efficient furnace. The furnace is located in an unheated 18' x 30' crawl space. The crawl space is vented to the outside with two 6 x 14 vents at opposite corners of the crawl space. The old furnace used combustion air...