Best Of
Re: When to NOT use sharkbite? A question
The 150+ year old floor joists in my house which are far below code would disagree.
The building codes are the minimum allowed, not the minimum that will work.
Me, I think building codes are a great invention.
ChrisJ
Re: When to NOT use sharkbite? A question
Old growth lunber is compleatly different then todays lumber.
pecmsg
Re: Is a bridge valve enough or do I need recirculating pump?
if you don’t have a dedicated return line from the farthest fixture, you can put a valve that connects the hot and cold under the sink. Then the hot recirculates back through the cold line.
Is that the bridge valve you are talking about?
It does require a pump. The pump could be on a timer, a motion detection, or a door switch. No need to run it 24/7
hot_rod
Re: Confused - Hydronic air handler VS heat pump VS heat pump plus furnance
If you’re using AC, a heat pump is a no brainer. Add a furnace to it if you like. We can abandon the boiler idea here.
Re: Confused - Hydronic air handler VS heat pump VS heat pump plus furnance
This is where things can get complicated, especially with the majority of contractors simply not well versed on the “house as a system” approach.
A sealed crawlspace is superior to a ventilated crawl. Additionally, an unconditioned crawl space is a bad idea. Stale air in your crawl almost always leads to indoor air quality issues. Ventilated crawl spaces are rarely done well.
The cost difference between a basement and a crawl is often very little (especially in the greater picture).
If you are committed to a crawl then make sure it has ample headroom and access.
For your proposed project, I would have the air handler that you plan to locate in the basement of the original structure serving the 1-story addition, with the trunk extended into the crawl. This is the simplest and most cost effective approach. Air handler is located “centrally” in the basement.
Re: My proposed Install
A 4 way motorized mixing valve works well, IF you have a low pressure drop boiler, CI for example. And the valve needs to have an actuator and controller. The control adjust the desired mix temperature and also protects the boiler. Additionally it can have an ODR function.
This was the go to mixing/ protection system when CI boilers were the main boiler used on low temperature radiant. It does not require a P/S piping. It works fine with one properly sized circulator.
If you had a high pressure drop boiler, you would need that separate boiler circ.
A 4 way valve is unique in that it has two mix points, the system and the boiler circuits.
Your system as described in past posts should work with a single pump. Although it has been a moving target as to what you are trying to accomplish :)
My vote was for a mod con, but since you went with CI you need to adjust piping, mixing, and protection accordingly.
hot_rod
Re: 2" steel pipe radiant!
frank lloyd wright was a great architect but not that great an engineer.
mattmia2
Re: Confused - Hydronic air handler VS heat pump VS heat pump plus furnance
There's a lot of conflicting info simply because many if not most do not understand how things work.
My 150+ year old house with steam heat typically runs around 25% RH in the winter, and that's with a humidifier dumping 6+ gallons of water into the air a day. Without that humidifier it really gets dry.
My dad's 2006 house with forced air runs around 35% RH without any humidifier at all and it's generally 10 degrees colder where he is. My house is very drafty and his isn't. It's that simple really.
Drafts cause low humidity in the winter, nothing else. It's not a mystery. Exhaust fans, bathroom fans etc also contribute towards this but most would rather lowering the humidity a little over smelling bathroom stink. You have to pick your battles.
A properly designed forced air system in a well insulated and sealed house with wood flooring up on a foundation is perfectly comfortable. If a house is drafty it'll generally be more comfortable with a radiant style system. Slab floors will be nicer if they're heated as well. It's best to look at a heating and cooling system as being part of the house, rather than separate. The entire thing is a "system". If you install a forced air system no matter how well designed into a drafty house on a cold slab you're going to feel cold all of the time and there's no gimmicks to fix it. Insulate the floor and seal up the drafts and it'll be comfortable.
ChrisJ