Community: Mechanicals

[Click map to enlarge]

Please register for a free account or sign in to ask and answer green building questions.

The usual rules of courtesy apply:
1. Be nice.
2. If you can't be nice, be polite.
3. If you can't be nice or polite — well, please be brief.

To attach a photo or illustration:
Under the box labeled "More explanation," look for the words "File attachments."
Click that, and you should be able to attach a photo.

Thanks for joining the conversation!


42 Answers

Solar thermal systems for heating water

Jin this is for you and Richard

Let's run the costs and the systems through the paces

so far I hear $16,000 for a Caleffi system and maybe that for labor? $32,000
saves $500 a year

CO2 production unknown to manufacture
Very little CO2 to run the ECM circulators

There are much less costly systems

NYSERDA here in NY is unveiling a new program this January
Will post more about it when they tell us more

Jin, Richard, others... what say you all

Asked By aj builder, Upstate NY Zone 6a | Dec 15 14
14 Answers

Unfinished basement, Cgi 5 gas boiler, Z vent. The outside air is making the basement cold. Can it be louvered?

Hi all,

So Ive just finished sealing the rim joist with 2" XPS (Dow Blue board) and spray foam, sealed the perimeter between the walls and floor with silicone, installed a air tight sump lid but was still getting drafts.

So Ive tracked it back to the Z vent for our CGi5 boiler, it seems the air is coming in through the z vent and back that way. It has the Z Vent termination cap on outside but was wondering if it could use a metal louver on the outside so when the boiler isnt firing it the drafts stay outside?

Asked By Darren Finch | Dec 16 14
38 Answers

Heating with modulating condensing units

So far my looking into the use of a modulating condensing unit has left me with
the following;

They are high tech
They cost more than some older tech
They need good water with proper hardness and PH
They need a tech that is trained to maintain them
They do not condense if the return water is above 125 degrees.
Many install set ups include primary, secondary and what I call tertiary loops which to me add cost.

I can't understand how we go from $1000 to heat water to $8000 for all the parts for a fairly basic

Asked By aj builder, Upstate NY Zone 6a | Dec 15 14
7 Answers

Flow control valves for radiant floor heating

I have high efficiency house in central Vermont. It has radiant tubing in the floor for heat. I am trying to get the on demand hot water heater, a Takagi, and the circulator pumps to run as little as possible. Electricity is the biggest obstacle. The house is off grid with PV and batteries. Both are a little on the small side. The house has 6 zones with flow valves on each. No zone is over 400 feet. Tubing is 1/2 inch PEX. Current Delta T when three or more zones are open is 10 degrees. I currently have all flow valves wide open.

Asked By Jon Olson | Dec 16 14
9 Answers

What about installing a cooktop downdraft vent/ducting in a slab?

I have installed two cook top downdraft vent/ducting systems with great success but never in a slab. In this case the duct would be embedded in the concrete slab with exterior grill through the perimeter foundation and still above grade. What should I look out for, take into consideration?

There will also be a return from an HVR system in the Kitchen area. (Thanks to the excellent article by Martin I am in dialog with Zehnder)

Asked By Caroline Di Diego | Dec 14 14
84 Answers

Modern (hydronic) heating and what all should start to know as of 2014

I stumbled upon this site to do with researching an update to a (hydronic) heating system I installed two decades ago.

So much has changed mainly the best change is the access we all have now to information.

This is the best read I have had off the internet to do with modern current (hydronic) heating.

Dana, besides your wealth of help here, this pictorial is great for the visual types like me.

http://www.duluthenergydesign.com/Content/Documents/GeneralInfo/Presenta...

Asked By aj builder, Upstate NY Zone 6a | Dec 4 14
8 Answers

Will my generator run a minisplit safely?

My new house will be heated with two minisplit heat pumps. Here in Maine, we have lots of power outages, so we're also putting in a whole house standby generator.

I've been informed by the Fujitsu installer that we should not plan to run the minisplits off the generator when the grid power goes out. We also may install a heat pump water heater and maybe even a heat pump dryer. We'll have some backup heat.

I have two questions:

1. Would the generator power damage the heat pumps or prevent them from operating?

Asked By stephen sheehy | Dec 13 14
1 Answer

Flitch Hydronic redesign thread

Flitch we need pics and pipe sizes and run lengths and details on what items are on the loops.

I have to put your pet bear here too cause I like the look of that furry animal.

Asked By aj builder, Upstate NY Zone 6a | Dec 11 14
4 Answers

Hot basement

I have just moved into a home with a wood burning furnace hooked up to the NG furnace and duct work. When I run the wood furnace (wf) the basement gets really warm. Should I cut a register into the cold air trunk? Thank in advance for any suggestions.

Asked By Dennis Krawchuk | Dec 10 14
8 Answers

Mini Splits winning the battle; with PV as a source let's even call it green.

Mini splits with PV are a great option even if not super insulated yet.

Pellet stoves do well, cost as much as a mini split and you have to attend to them.

Oil seems outdated and expensive and smells in old systems and very expensive to install.

Solar thermal there are a few that feel they can justify this, not all.

LP is never going to be as inexpensive as NG, NG is a good value for now, and maybe half a century more, depends on if we start really selling our frack fuel to Europe, which I doubt for now as they have Russia and Russia needs the sales Putin threats or no threats.

Asked By aj builder, Upstate NY Zone 6a | Dec 11 14
Register for a free account and join the conversation


Get a free account and join the conversation!
Become a GBA PRO!