4 way or injection mixing

hr

Check out this article.

hot rod

http://www.pmengineer.com/CDA/ArticleInformation/features/BNP__Features__Item/0,2732,84948,00.html

<A HREF="http://www.heatinghelp.com/getListed.cfm?id=144&Step=30">To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"</A>

eleft_4

hr,

Good article, almost a no brainer to figure the one to use by Sig's stats.


Cost 919 more for 4way Only 3.73 a season more to operate variable! Do the math.

How many seasons @ 3.73 to break even.

Keep reading and feeding our brains.

Thanks al

heatboy

Great article.

Some very good points were made. I wish John would have brought condensing technology into the mix. A motorized three would seem to be the ideal choice when condensing. Both VSI and 4-way raise return water temperatures, which is not desirable when using a condensing boiler.

Warm Regards,

heatboy

climatecadvanced.com

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

Paul Pollets

He also made note

that he only extrapolated several sizing scenarios. What if the motor on the 4 way is variable speed? Great article and certainly timely. One would want to read Joe Fiedrich's articles (archived on the Stadler site) to get a bigger picture on the why's and wherefores. Will I be changing to injection? Nope. I can get 2 water temps out of a single 4 way and pumps are plugn'play with Vitotec.

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

Alan(CaliforniaRadiant)Forbes

Excellent Info.

Thanks for the link.

Best wishes,

Alan

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

kf_2

4-way vs. injection

The size systems that John compared were larger commercial systems. What he did not elaborate on is the fact that with an injection system there are a minimum of three pumps needed. A boiler pump, injection pump, and a system pump. On a system with 500,000 MBH - 1,000,000 MBH two of these pumps can be quite large and expensive to purchase (possibly in the thousands) as well as to operate. On a system with a 4-way valve there is usually only a system pump needed.

In a smaller residential system the costs between a 4-way valve and actuator and injection system are quite comparable even without the addition of 2 more pumps to make an injection system work.

Most important, if I'm a building owner and my 4-way valve actuator craps out at 2:00 AM I can manually adjust the valve to insure that the building has heat. Try doing that with an Injection pump.

kf

RB_2

I couldn't agree more....

I wrote our friend Siggy and thanked him for the article...it is well written, a fair comparison and left the reader with an objective view...but I also gave him our list prices and Cv's and asked him to re-evaluate the analysis...(a wink is as good as a nod...if ya get my drift)

You have to admit the man is a great technical writer...one of my favorites!

RB