Recycled heat off Raypaks?

[Waxman]

There must be a way to use some heat off my 2 large Raypak boilers as extra heat for my IBA bay.

I have seen a fan unit that connects to a vent pipe. That makes sense because the vents get plenty hot and that heat is not captured except to blow out the stack. Will I capture enough heat this way to make any difference in bay temp?

Any ideas???

 

[GoBuckeyes]

I know it sounds like a logical idea, however, Huron Valley told me you run the risk of condensation falling back down on to your heat exchanger. The hot flue gas condenses on the colder stack unit. Flue gas is corrosive and therefore not a good thing to have falling back on your heat exchanger.

 

[Waxman]

then what about running another hot water line to a blower unit?

 

[mjwalsh]

Check with Raypak ----- an engineer told me that on a newer model they built it for & with similar heat reclaim as you describe. We have a 399K Raypak that is dormant because our more efficient Hydrotherm pulse condensing boilers are available at night when the Raypak tends to be needed for our deicer pad area.

Another approach which is somewhat unique to our situation relates to our laundromat sharing the same wall as our new pet wash. It appears to be worthwhile capturing the surface heat off of 8 of our 30 lbs laundry clothes dryers' exhaust. There are several key differences that appears to be working in our favor vs doing it on the boiler. Condensation is not a problem because of the extra force of the dryer fans & the fact that we are blowing our heat reclaim fan around the 19 foot long duct (approx. 17"x16" cross section). The duct is horizontal where the heat exchange is occurring so drainage does not go back into the burner area. We have a straight away shot to clean the lint so it looks like a win win. The outer chamber has 2 inches of insulation so heat migration during the summer is not an issue or when the dryers are not going the cold doesn't seem to migrate either. The metal does conduct the cold from the outside portion some though. It would be nice to have the where with all to be able to present the exact logging of the temperatures that is somewhat happening from the ethernet enabled PLC that is controlling it.

 

[Waxman]

Checked the Raypak website and couldn't find anything.

Sent them an email; see if they respond.

Thanks.

 

[ToFarGone20]

Waxman...I will take a picture of our system and post it.

 

[soapy]

Most Raypacks run about 65 to 70% efficient. That means at least 30% of the gas you are paying for is going up the stacks. A more effecient boiler in the 90+ range will save you 25% on your heating bills. You will have to figure out your payback and if it is right for you to convert to a better boiler.

 

[Waxman]

what is the difference in efficiency? what creates it? can a boiler be modified to make it more effieient.

my Raypaks are practically new and an upgrade is not in the cards at this point, i think.

 

[soapy]

Look at your boiler to see what the input BTU rating is, let say around 200,000 btu then look at the output BTUs if it says 140,000 BTUs you can divide the output BTus by the input BTUs and in this example get a rating of 70%. Newer technology boilers are normally over 90%.

 

[Waxman]

Soapy you were right about the efficiency rating of these.

Sadly, I'm a ham and egger and will wait till these are a year older b4 replacing.

I am talking w/my plumber to install another heat line going to a modine unit to blow auxilliary heat into the iba bay.

 

[ToFarGone20]

Sorry it took me a while. The name on ours is "Therma-Stak Heat Reclaimer".
It was made by Energy Saving Devices LTD. Lynbrook New York. Scavenges heat from boiler exhaust.

 

[Waxman]

what was the unit's cost?

thanks.

 

[ToFarGone20]

They are 25 years old....not sure what they would be now.