What is a 351' house?

351 sq foot house. Sorry. It is a tiny cottage.

I would be inclined to leave the heating system since it is a rental, and let the tennants go to the laundromat. Colorado can get cold. Best to have a good heating system.

Prospective tenants want a washer and dryer.

Thanks everyone for your concerns about my investment strategy. This is one of seven rental units we own, all cash flow well. I am concerned about having quality tenants, and the pool I want to attract wants in-unit laundry.

Any ideas about what type of heating unit I should get?

Home Depot or Lowe’s have wall units called Ventless gas heater ($150-$250), they are small and easy to install.

Mini split is probably your best bet. As small as this place is you could do a window unit or two one on one side one on the other. Colorado isn't what I consider an extreme climate either for heating or AC. It can get cold there but not like extreme cold like say Chicago.

If you put in window units, tenant may complain about noise. The other is that the tenant takes the window units when they move out (or gives burglars a easy way in). Having a mini split installed it's quieter, more efficient and attached to the structure.

I'm not really a fan of mini splits, but with such a small foot print there is little else that would work well.

You can get one-piece washer/dryer combos that fit under a kitchen countertop (maybe replace a dishwasher?), or portable units that move in and out for use. Have you considered these? - a lot less expensive than a new HVAC system.

LOL, the kitchen is even smaller. No dishwasher sadly. Great idea, unfortunately the kitchen is even smaller.

For health and liability reasons, it's best to avoid ventless heaters. Through-wall vented heaters are fine.

Modern mini-split heat pumps are outstanding even in very cold weather, so that's a good option too.

I think I would be looking into vented gas wall heaters. My grandparents had those in every room, some small some large. The alternative would be a mini-split.

DavidR, ventless heater is same as ventless fireplace which we have one. Would you please let me know for what health and liability reason? The stores all over the country are selling those ventless heaters and fireplaces. We should know if something wrong with it. Please do tell. Thanks

Summersrhythm, I remembered reading this article on realtor. com about a week ago. I had to go relook it up to post the link. I also typed health risks, ventless fireplace into google, and there is a variety of things that come up. You might want to read it all. https://www.realtor.com/advice/home-improvement/is-a-ventless-gas-fireplace-safe/

I don't think I would do the ventless, Especially because this property may work as a furnished traveling nurse rental, and something that operates like a hotel or with a thermostat might be better. I am leaning toward mini-split or PTAC unit.

Thanks Cat, Kim and David. Ours is linked with propane at weekend house. Propane is even dirtier than NG. We haven’t used it since we bought the place last year, it won’t turn on for some reason. I do have gas ranges at both places and will have to watch out. Thanks again for mentioning.

To be clear here, I wouldn't necessarily turn on the range hood just to boil a kettle of water on the gas stove. (Well, maybe in some of the newer, very tightly sealed houses.)

However, the oven typically uses around 16,000 BTU. Add a burner and you're over 20K. That's when you need ventilation for sure.

Thanks for the info. Will be careful with the gas range usage now. Don’t really bake much since I pretty much burn everything. :-)

Back to the original question, I use these ceiling-mount electric cove heaters for supplemental heat in the two outside corner rooms and in the bathroom. Each room will have its own thermostat to run it. I love the way the radiant heat feels, it is silent, and the set-back thermostat is great to use. Comfort Cove Radiant Heaters

I have asthma and will not use a gas stove. Those ventless gas heaters are a menace! So are the fireplaces.

When I lived in Colorado i had a cabin at 8200' in the Apsen park/Conifer area. Gas company installed a Rinnai (vented) unit. it worked extremely well. Only rib is that it was somewhat undersized. Salesman did not take into account the vaulted 12/12 ceiling and the minimal insulation. below 15 degrees it had troubles keeping up. The next bigger unit coast only $100.00. No AC, but the summers were so mild where i was it was not needed. https://www.rinnai.us/taxonomy/term/3241