Heating Help

need a reasonablly-priced tankless water heater as a temp

while we rip out the boilers.  Need seperate intake and pvc exhaust.  Any suggestions?  Thanks  Mad Dog

if its just...

for DHW can you just get a 50 gallon electric? Done that before and it worked great....no venting needed.

Matt

50 gallon electric with a tempering valve ... run it at 150 or so .
We do this alot

Ditto

Ditto on the above posts.  Used to do this all the time on residential and light commercial change outs.

Thanks, but I should have clarified

that this is an apartment complex...a 50 gallon electric would never recover fast enough.  I keep a 40 gal in the barn for oil to gas conversions, so I can rip everything out and still give them hot water.  Nope, tankless is the way to go here.  I know the condensing tanklesses can be vented with pvc, but the Navien and Noritz are kinda pricey.  These can almost be throwaways.  Mad Dog

Here is an odd....

thought... Can you put in a standard  outdoor tankless that mounts outside and pipe w/ pex back into the building? No venting needed.

Same idea but different.

Same idea but different.

Temp in a oil or propane unit that is installed in an enclosed structure on a trailer.  Basically a water heating system on wheels.  Somewhere on the wall I saw a picture of someone who put a furnance on some pallets and used it to keep a concrete slab warm during a winter construction project.

If the load is big enough, you can rent entire heating plants on semi-trailers for temporary installations, but of course you already knew that.

Didn't somebody else asked about putting a steam boiler in a box truck for a portable kitchen?

Tankless

Will never keep up with an apartment building unless everyone has a schedule ...
Apart # 1 8:00
Apart # 2 8:15
You need a oil HWH with a large tank 
whats in there now Matt ?

little 10 gpm everhots

and a few boiler rooms have a 50 gallon storage tank too.   These aren't HUGE apartment bldgs...maybe 10 units per bldg  Mad Dog

Boss wont go for that

Doesn't wanna spend $$$ on  a trailer  Mad Dog

thought of that too

Still in the mix  mad Dog

Temporary Tank

We once had a similar situation, where the load was more than we could "temporily" supply because the original boiler installation was such a cluster ? that we would need a couple of days to clean it up and get the new boiler online.
We put the 80g indirect in place, plumbed it to the domestic lines as needed.  Then we took 2 electric 20g / 120v tanks that we plugged in where we could on seperate circuits and used Taco 006 pumps to pump out of the cold and into the hot on the 120g.  So essentially, we had 2 "heating" tanks working to keep the tank hot.  We left the Taco's running 24/7 and did the connections with pex (we only had to run one of the tanks from 20' away to get on a seperate electrical circuit.  We set both "heater" tanks to the same temperature and had no issues while we installed the new boiler over the next three days.

Essentially, you could do the same with 2 (or 3, or 4, etc) 220v 40g tanks if you have the electrical feeds to do it.  There's a point of ridiculous, but don't have enough info on your precise requirements to know where that is yet.

Trained Tenants....

Oh yeah, I forgot. Tenants live in tenements,,, OK, take two.

Learned Residents... I have had situations before whereby there was not enough space to set a good temporary water heater. In most cases, we had a couple of recycled self contained gas fired condensing tank type high efficiency water heaters that we'd set outside the boiler room, literally outside, and run PEX and CSST to for temporary DHW. This tank was behind a welded wire mesh fence to keep busy fingers at bay, with DANGER signs in English and Spanish on the fence.

We would then establish a use schedule, giving the people who live in EVEN numbered apartments use between 4 AM and 5:30 AM, and the balance of the ODD apartments use between 5:30 AM, and 7 AM. We also put the people on notice that they could expect shortages of hot water but that they would be short in duration. We also told them that if their available time slot didn't work out due to scheduling, etc, that they could swap their slot with another resident.

We also encouraged them to bathe their children at night, right before bed time to spread the loads out over a longer period of time. These "systems" usually were on line for not more than a week, and the residents actually did an excellent job of working together to stretch the DHW resources so that everyone got what they needed.

Being on the Isle of Long, peoples attitudes may be different than they are out here in the WIld WIld West, but it is still worth a shot.

Your milage may vary...

ME

attitudes is right

we'll see   md

Thanks for all the great ideas

Mad Dog