Insulation under Boiler?

nheater

<span style="font-size:12pt">Ok, here’s the question I just got.</span>

<span style="font-size:12pt"> </span>

<span style="font-size:12pt">Can I insulate under a Peerless ECT 150K boiler (steam)?</span>

<span style="font-size:12pt">There are three inch concrete blocks holding it off the floor.</span>

<span style="font-size:12pt">I have installed new heat pumps and HE furnaces with 2” foam under them.</span>

<span style="font-size:12pt">The space is unheated except for any thing that radiates off the furnace and stack.</span>

<span style="font-size:12pt">Yes, I understand that the cast iron is much heavier.</span>

<span style="font-size:12pt">The thought is that the floor is 50ish degrees and that much like the others installs they use it as a thermal/vibration break.</span>

<span style="font-size:12pt">I was thinking 2” rigid foam with something solid that distributes the weight.</span>

<span style="font-size:12pt">Has anyone installed one using this method?</span>

<span style="font-size:12pt">Thoughts? </span>

<span style="font-size:12pt"> </span>

<span style="font-size:12pt">Please hold out on the sanity comments, the jury is still out on that.</span>

Tim McElwain

You want to be careful

if secondary air for combustion is distributed from the bottom of equipment changes to that area can affect combustion.

kcopp

you could....

use rock wool but NOT foam...... It is combustible. If the boiler is already installed I would not bother. Although I will say that is a "problem" w/ many American made boilers... that lack of detail leads to more heatloss. The MPO/ Megasteam does address that.

bob_46

Combustible floor?

You don't say if the floor is combustible or not. If the floor is combustible you have to use the cement blocks with the holes horizontal so air can circulate through them or a base supplied by the manufacturer if they make one. A concrete slab of the same thickness won't work. i have seen cast boilers on a 4" slab on wood start the floor on fire.

Unknown

Isolation of boiler

Ok first, the Boiler is on four 3" concrete blocks on top of a concrete floor.

so, all four points of contact to the boiler cast iron are touching the cast blocks.

the space is unheated except by the boiler which keeps the room at around 70 degree (except the floor) due to a very long horizontal exhaust pipe run.

I won't be blocking any air intakes on the bottom.

I just want to stop the contact with 50 degree ground temp.

The thought is to help efficiency by not allowing heat to be taken away from the boiler

I know that this effects the heat pumps and new gas furnaces thats why we install the 2" insulation.

Note: I will not use anything that wouldn't be rated for the job.

JohnL_2

Insulating Bottom of Boiler

I would not recommend puting foam insulation under the boiler because it would cause a potential fire hazard.  It is my understanding that the boiler is placed on blocks for water protection.  If you are going to put any type of insulation material under the boiler, you should probably stick with mineralwool or calcium silicate block.