Shop Heating with propane

Re: Shop Heating with propane

Darryl

I sometimes use a propane heater with force fan. The kind that builders use. I always turn it on for a bit before I start making dust. Afraid to run it while there is wood shavings in the air. After I tke the chill off I run and electric heater.

Re: Shop Heating with propane

Jorge

Darryl,

I am talking about heating antifreeze and circulating it through the slab, not heating the air.

Re: Shop Heating with propane

Barry Irby

Don't know a lot about it, but my understanding is propane is about triple the cost of Natural Gas.

You obviously know you have to place the piping for this in the slab, so if you have poured the slab already it's too late unless you want to pour a topping slab.

These systems can be very nice in some aspects. Safe, quiet, don't blow the air around. OTOH, they don't filter the air and they are ponderous. They take a LONG time to heat up and cool down. Hours. So basically you have to leave them on all winter. You can't "knock the chill off", work for a few minutes and leave.

You also should install insulation under the slab and heavily around the perimeter, especially the edges.

I think the current technology uses high density PEX (polyethylene) pipe in the slab. Radiant slabs are rare here in the South.

Re: Shop Heating with propane

Jorge

Barry, I did lay the pex way before the slab was poured, My home is heated likewise, except the furnace is oil burner and I am moving away from that. Natural gas is not an option here in this island.

Re: Shop Heating with propane

mikeee12345

Jorge,

I have worked on a few of these systems over the years. You have several options if you

want to use propane. You can install a propane gas water heater and circulating pump and

use a thermostat and contactor to cycle the circulation pump. Your other option would be a propane fired boiler system with a circulating pump and similar control scheme for the pump. You also need to have an expansion tank installed on the system to account for expansion and contraction of the volume of the fluid as it expands when heated and contracts in volume while cooling.

Re: Shop Heating with propane

Jeff Smith

I'm just finishing up setting up a new shop - we, too, live on an island. Haven't decided what to heat the shop with, but our house is heated with a propane fired boiler that also functions as hot water heater and supplies radiant heating for the main floor and about 1/3 of the upstairs.

Seems to work well - we've owned it for two years so far. Just getting familiar with the system, but it seems more economical than the forced air furnace we had in ourlast home on the mainland.

All told, we fill our 500 gal tank twice a year (about 750 - 800 gals/yr. total). Our cost for gas - propane (including cooking), electricity and water are about a third of what we're used to...

Our system is a shallow pour over 2x12 truss floor, fully insulated from below with a foot of foilfaced batting. It heats fast - within 20 minutes, and retains good temperature. It is setup to cool in the summer, but we haven't had a need yet.

Re: Shop Heating with propane

mikeee12345

You can also incorporate an electric water heater into this type of system and use a

wind turbine or solar panels to power the system. With a well insulated shop floor

and building you can use the concrete floor as your storage system for the energy.

As long as you have wind or sun the energy is converted into heat which goes into

the concrete floor. You could also use this energy for a wood drying kiln if you ended

up with an excess of energy/heat from your system. A fan/coil unit can be easily

added to provide a forced air system for a small room.

Question....

Barry Irby

If you want to use solar power for heat why would you use PV panels?

In the late 70's I built a very low tech solar water heater out of scavenged materials. It was about 4" by 16' and provided about 40 gallons of very hot water any day the sun shined.

OTOH, once you had all the hot water you wanted and the floor was warm or in summer the system would not be as handy as PV.

Another thought might be to use a heat pump water heater. ?????

Re: Question....

mikeee12345

Barry,

With a wind turbine or PV system, the storage of the energy is the expensive part of the system.

Using a water heater element to convert the energy into heat allows you to easily heat the liquid

used in your heating system and transferring the energy to your concrete floor which ends up being

the storage mass system for the energy produced. A well insulated concrete floor and building will

stay warm for a number of days after coming up to temperature. A bank of batteries can get expensive

and requires some maintenance for reliable service. You could also utilize a large insulated water tank

to hold hot water as your energy storage system. I have seen various system employed to provide heat

on hydronic systems. It really comes down to what your property will allow and what you can afford.

You could also use a passive hydronic solar panel system that converts the sun light into heat and heats the

liquid in the system and then circulates the liquid through the concrete floor. This type of system usually requires a small circulating pump and expansion tank to move the fluid through the system.

Re: Shop Heating with propane

George Van Beynen

Jorge, 20 years ago I installed a wall mounted propane boiler in my workshop and a propane boiler and hot water maker in the house. Both systems work very well. It is important to size the pump properly to get an adequate temperature drop on all loops. I also switched from a wall mounted thermostat to a slab temperature sensor, it seems to control the temperature more evenly.

In 2008 I installed a Garn high efficiency wood boiler. It heats the workshop and house and heats the domestic hot water 12 months a year. I still have the propane boilers for backup when I am gone for an extended period of time.