Takagi direct vent install

[Eric in North TX]

I'm planing an install of a Takagi T-KD20 in the first floor of a 2 story addition. I'm a little confused by their install instructions. Do I need to go through the second story roof with the exhaust vent? My first choice would be to make it as short as possible. There are no first floor windows on that wall, & only 2 on the entire wall, both 15' or more from the intended location, there is a gable vent ~ 20' above the intended location.

[Eric in North TX]

Perhaps I should have mentioned that a Takagi T-KD20 is a direct vent tankless hotwater heater.

[thefavorite]

I just installed the same thing... Works great, but beware of the temperature. (It gets REALLY HOT). Also, be aware of your flow rate, we had to change a few aerators (sp).

As far as venting, I would vent it out the side of the first floor as long as there are windows close...

[Eric in North TX]

. Works great, but beware of the

Could you elaborate? Temperature; too hot or too cold? Flow rate; seriously reduced? I'm running an 85 psi booster, I hate wimpy water pressure. Vent; I plan to run it out the wall behind the unit, curious if I need to get it above the roof.

[Wayne Whitney]

My understanding is that a direct vent appliance typically has its vent terminated at the side wall and that there is no need to get above the roof. The appliance's manual should list the necessary clearances between the vent termination and varous other features of the house.

BTW, if you live in a climate where it never freezes, consider an exterior model, it makes venting very easy.

Cheers, Wayne

[PSZach]

first floor of a 2

The Takagi Exhaust Venting instructions place a lot of burden on the installer to be in accordance with the section on venting of equipment in the latest edition of the National Fuel Gas Code. Based on your criteria, if the gable vent has a negative pressure or in other words does draft inwardly, then there should be a concern.

For venting parts that would comply with Wall Thimble Termination consider visiting

.

For the actual 4? ProTech Systems FasNSeal Wall Thimble with Termination Telescoping Elbow Appliance Adapter mentioned in the Takagi Exhaust Venting instructions, click here?.

Here some instructions from another manufacture ?Rheem?

They talk about horizontal termination in the installation section.

[MDT at Paragon Home Inspection]

I have these installed in several buildings as sidewall vent units.

1) If your's is a freezing climate, make sure you install a TK-TV03 back draft preventer.

2) If you want output hotter than 122F, you will need to install an external TK-RE02 controller.

3) You will need a TK-BK01 wall mount kit.

4) Takagi specs a TK-TV05 wall-mount terminator kit. It's a big unit, make sure that you allow a full 16" stud bay for its installation, and plan the heater location with this in mind. It's helpful to have the fill kit on site so plumbers and electricians can visualize what's involved.

5) Don't forget that the unit will need 120V power.

6) You will need 2x wall SS vent pipe and fittings (check with Takagi, at the time I installed they had approved two manufactures), and HT sealant. It's simplest if you order the pipe, fittings and TV-03 (if used) from the same source, so everything fits.

7) You will need .75" gas pipe (or equivalent CSST) ALL THE WAY to the heater - you are putting in a 190,000 BTU appliance - probably, larger than your gas furnace or boiler - and you may need to upsize piping or even, on low pressure NG systems, an unsized meter!

8) You will need a TPRV rated for 200K BTU.

On later installs I used these isolation valves, they make for a cleaner install, you can order either .75" sweat or IPS:

Michael Thomas Paragon Home Inspection, LLC Chicago, IL mdtATparagoninspetsDOTcom eight47-475-5668

[Eric in North TX]

Thanks for your reply! That's a very detailed and helpful post. I'll be using LPG and the proposed site is a couple of yards from the tank, so a new line shouldn't be much problem, I'll talk to my propane guy to see if I can flow enough gas to run it, and what to do if not, he is a certified, licenced, LPG plumber, he will know what to do. I may not need much chimney, as the unit should mount right to the TK-TV05 wall-mount terminator kit. Everything is right there as it will replace an electric one already occupying that site. It does freeze here maybe 2 weeks a year, but the spot it will occupy will be somewhat heated, it is a large utility closet under landing for the stairs. though it won't be directly heated it should stay 50 degrees or better, I'll still look into the back draft preventer.